LK204-7T-1U-YG-LV

LK204-7T-1U Including the LK204-7T-1U-USB va riant Technical Manual Revision 2.7 PCB Revision: 1.0 or Higher Firmware Revision: 5.0 or Higher 1 Revision History Revision 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 0.1 Date January 4, 2018 January 14, 2015 June 26, 2014 March 12, 2014 March 10, 2014 June 24, 2013 October 29, 2012 December 14, 2011 November 18, 2011 Description Correction to Set Non-Standard Baud Rate command Revision to GPO Indicator Table Revision to GPO On and Off commands and LED Indicator Table Revision and correction to Colour in Ordering Options Revision to the Dimensional Drawing Updated Power/Communication Header Updated Alternate Power Header Initial Release Initial Concept Author Divino Clark Martino Martino Martino Clark Clark Clark Clark 2 Contents 1 Introduction ............................................................................................................................................... 5 2 Quick Connect Guide.................................................................................................................................. 6 2.1 Available Headers ............................................................................................................................... 6 2.2 Standard Module ................................................................................................................................ 7 Recommended Parts ............................................................................................................................. 7 Serial Connections................................................................................................................................. 7 I2C Connections ..................................................................................................................................... 8 2.3 USB Module ........................................................................................................................................ 9 Recommended Parts ............................................................................................................................. 9 USB Connections ................................................................................................................................... 9 3 Software ................................................................................................................................................... 10 3.1 uProject ............................................................................................................................................. 10 3.2 Application Notes.............................................................................................................................. 11 4 Hardware.................................................................................................................................................. 12 4.1 Standard Model ................................................................................................................................ 12 Extended Communication/Power Header .......................................................................................... 12 Serial DB9 Connector .......................................................................................................................... 12 Power Through DB9 Jumper ............................................................................................................... 13 Protocol Select Jumpers ...................................................................................................................... 13 4.2 USB Model......................................................................................................................................... 14 Mini USB Connector ............................................................................................................................ 14 Alternate USB Header ......................................................................................................................... 14 Alternate Power Connector ................................................................................................................ 14 4.3 Common Features ............................................................................................................................. 15 General Purpose Outputs ................................................................................................................... 15 Dallas One-Wire Connector ................................................................................................................ 15 5 Troubleshooting ....................................................................................................................................... 16 5.1 Power ................................................................................................................................................ 16 5.2 Display ............................................................................................................................................... 16 5.3 Communication ................................................................................................................................. 17 3 5.4 Manual Override ............................................................................................................................... 17 6 Commands ............................................................................................................................................... 18 6.1 Communication ................................................................................................................................. 18 6.2 Text.................................................................................................................................................... 19 6.3 Special Characters ............................................................................................................................. 21 6.4 General Purpose Output ................................................................................................................... 24 6.5 Dallas One-Wire ................................................................................................................................ 25 6.6 Keypad............................................................................................................................................... 26 6.7 Display Functions .............................................................................................................................. 28 6.8 Data Security ..................................................................................................................................... 29 6.9 Miscellaneous ................................................................................................................................... 30 7 Appendix .................................................................................................................................................. 31 7.1 Command Summary ......................................................................................................................... 31 7.2 Character Sets ................................................................................................................................... 34 7.3 Environmental Specifications............................................................................................................ 35 7.4 Electrical Tolerances ......................................................................................................................... 35 7.5 Optical Characteristics ...................................................................................................................... 35 7.6 Dimensional Drawings ...................................................................................................................... 36 8 Ordering ................................................................................................................................................... 37 8.1 Part Numbering Scheme ................................................................................................................... 37 8.2 Options .............................................................................................................................................. 37 8.3 Accessories ........................................................................................................................................ 38 9 Definitions ................................................................................................................................................ 40 10 Contact ................................................................................................................................................... 40 4 1 Introduction Figure 1: LK204-7T-1U Display The LK204-7T-1U is an intelligent alphanumeric liquid crystal display designed to decrease development time by providing an instant solution to any project. In addition to the RS232, TTL and I2C protocols available in the standard model, the USB communication model allow the LK204-7T-1U to be connected to a wide variety of host controllers. Communication speeds of up to 115.2kbps for serial protocols and 100kbps for I2C ensure lightning fast text and graphic display. The simple command structure permits easy software control of many settings including backlight brightness, screen contrast, and baud rate. On board memory provides up to forty custom characters which can be saved within the unit and recalled for start screens, bar graphs or larger numbers. User input on the LK204-7T-1U is available through a built-in seven key tactile keypad. Three bi-colour LEDs provide visual outputs on each model. In addition, the option of a Dallas One-Wire header provides a communication interface for up to thirty-two devices. The versatile LK204-7T-1U, with all the features mentioned above, is available in a variety of colour, voltage, and temperature options to suit almost any application. 5 2 Quick Connect Guide 2.1 Available Headers Figure 2: LK204-7T-1U Header Locations Table 1: List of Available Headers # 1 2 3 4 5 6 7 Header Alternate Power Connector Communication/Power Connector DB9 Serial Header Mini USB Connector Alternate USB Dallas One-Wire GPO Header Mate PCS SCCPC5V/BBC CSS1FT/CSS4FT EXTMUSB3FT/INTMUSB3FT None Offered Temperature Probe None Offered Population All Models Standard Model Only Standard Model Only USB Model Only By Custom Request Only By Custom Request Only All Models 6 2.2 Standard Module The standard version of the LK204-7T-1U allows for user configuration of three common communication protocols. First, the unit can communicate using serial protocol at either RS323 or TTL voltage levels. Second, it can communicate using the Inter-Integrated Circuit connect, or I2C protocol. Connections for each protocol can be accessed through the four pin Communication/Power Header as outlined in the Serial Connections and I2C Connections sections below. Recommended Parts The most common cable choice for any alphanumeric Matrix Orbital Display, the Communication/ Power Cable offers a simple connection to the unit with familiar interfaces. DB9 and floppy power headers provide all necessary input to drive your display. Figure 3: Communication/Power Cable (SCCPC5V) For a more flexible interface to the LK204-7T-1U a Breadboard Cable may be used. This provides a simple four wire connection that is popular among developers for its ease of use in a breadboard environment. Figure 4: Breadboard Cable (BBC) Serial Connections A serial interface provides a classic connection to the LK204-7T-1U. The Communication/Power Cable is most commonly used for this set up as it provides connections for DB9 serial and floppy power cables. To place your board in Serial mode, adhere to the steps laid out below. 1. Set the Protocol Select jumpers.  RS232: Connect the three jumpers* in the 232 protocol box with the zero ohm jumper resistors provided or an alternate wire or solder solution.  TTL: Connect the two jumpers* in the TTL protocol box. *Note: Jumpers must be removed from all protocol boxes save for the one in use. 7 2. Make the connections. a. Connect the four pin female header of the Communication/Power Cable to the Communication/Power Header of your LK204-7T-1U. b. Insert the male end of your serial cable to the corresponding DB9 header of the Communication/Power Cable and the mate the female connector with the desired communication port of your computer. c. Select an unmodified floppy cable from a PC power supply and connect it to the power header of the Communication/Power Cable. 3. Create.  uProject or a terminal program will serve to get you started, and then move on with your own development. Instructions for the former can be found below and a variety of application notes are available for the latter at www.matrixorbital.ca/appnotes. I2C Connections A more advanced connection to the LK204-7T-1U is provided by the I2C protocol setting. This is best accomplished using a breadboard and the Breadboard Cable. Power must be supplied from your breadboard or another external source. To dive right into your application and use the LK204-7T-1U in I2C mode, get started with the guidelines below. 1. Set the Protocol Select switches.  I2C: Ensure that the two I2C jumpers in the corresponding protocol box are connected while all others are open. 2. Make the connections. a. Connect the Breadboard Cable to the Communication/Power Header on your LK204-7T-1U and plug the four leads into your breadboard. The red lead will require power, while the black should be connected to ground, and the green and yellow should be connected to your controller clock and data lines respectively. b. Pull up the clock and data lines to five volts using a resistance between one and ten kilohms on your breadboard. 3. Create.  This time you're on your own. While there are many examples within the Matrix Orbital AppNote section, www.matrixorbital.ca/appnotes, too many controllers and languages exist to cover them all. If you get stuck in development, it is possible to switch over to another protocol on the standard board, and fellow developers are always on our forums for additional support. 8 2.3 USB Module The LK204-7T-1U-USB offers a single USB protocol for an easy connection to a host computer. This simple and widely available protocol can be accessed using the on board mini B style USB connector as outlined in the USB Connections section. Recommended Parts The External Mini USB cable is recommended for the LK204-7T-1U-USB display. It will connect to the miniB style header on the unit and provide a connection to a regular A style USB connector, commonly found on a PC. Figure 5: External Mini USB Cable (EXTMUSB3FT) USB Connections The USB connection is the quickest, easiest solution for PC development. After driver installation, the LK204-7T-1U-USB will be accessible through a virtual serial port, providing the same result as a serial setup without the cable hassle. To connect to your LK204-7T-1U-USB please follow the steps below. 1. Set the Protocol Select jumpers.  USB: The LK204-7T-1U-USB offers USB protocol only. Model specific hardware prevents this unit from operating in any other protocol, and does not allow other models to operate in USB. Protocol Select jumpers on the USB model cannot be moved. 2. Make the connections.  Plug the mini-B header of your External Mini USB cable into your LK204-7T-1U-USB and the regular USB header into your computer USB jack. 3. Install the drivers. a. Download the latest drivers at www.matrixorbital.ca/drivers, and save them to a known location. b. When prompted, install the USB bus controller driver automatically c. If asked, continue anyway, even though the driver is not signed d. When the driver install is complete, your display will turn on, but communication will not yet be possible. e. At the second driver prompt, install the serial port driver automatically f. Again, if asked, continue anyway 4. Create.  Use uProject or a terminal program to get started, and then move on with your own development. Instructions for the former can be found below and a number of application notes are available for the latter at www.matrixorbital.ca/appnotes. 9 3 Software The multiple communication protocols available and simple command structure of the LVK204-25 means that a variety of applications can be used to communicate with the display. Text is sent to the display as a character string, for example, sending the decimal value 41 will result in an 'A' appearing on the screen. A number of control characters are also activated. Commands are merely values prefixed with a special command byte, 254 in decimal. While many software programs are available to communicate with the LVK204-25, a number of more common samples are detailed in depth below. Table 2: Reserved Control Characters 8 Backspace 10 Control Characters Line feed / New line 12 Clear screen / New page 13 Carriage return Once the correct communication port is identified, the following communication settings can be applied to communicate correctly with the LK204-7T-1U. Table 3: Communication Settings BPS 19200 Data Bits 8 Parity None Stop Bits 1 Flow Control None Finally, with a communication port identified and correctly setup simple text strings or even command bytes can easily be transmitted to control your display. 3.1 uProject The Matrix Orbital alphanumeric display tuner, or uProject, is offered as a free download from the www.matrixorbital.ca support site. It allows the basic functionality of any display* to be tested using a simple graphical user interface system. While basic functionality can be tested using the GUI portion of the program, more advanced users will enjoy the scripting capability found in the uploader tab. Here commands can be stacked, run, and saved for later use. Although many commands are available to be dragged into the script dialog, perhaps the most powerful is the raw data command found in the other branch. *Note: The uProject AutoDetect function will not perform correctly when a USB display is connected. Please manually configure any USB display. 10 This command allows raw bytes to be sent to the display, permitting many different formats for entry and displaying in decimal notation. Any command from this manual may be entered in decimal notation separated by slashes. /254/ /88/ Figure 6: uProject Command Again, the clear screen command is sent to a connected display, this time using uProject raw data command style. Scripts can be run as a whole using the execute command from the script menu, or as single commands by selecting execute once. Before issuing commands, it is a good idea to ensure communication with a display is successful using some of the more basic GUI functions in the main window. This program provides scratch pad upon which a tome of display projects and ideas can be assembled. 3.2 Application Notes Full demonstration programs and code are available for Matrix Orbital Displays in the C# language from Simple C# AppNote Pack in the Application Note section at www.matrixorbital.ca/appnotes. Difficulty increases from beginner, with the Hello World program, to advanced with the Dallas One-Wire temperature reading application. Many additional applications are available in a number of different programming languages. These programs are meant to showcase the capability of the display and are not intended to be integrated into a final design. For additional information regarding code, please read the On Code document also found on the support site. 11 4 Hardware 4.1 Standard Model Extended Communication/Power Header Table 4: Communication/Power Pinout Figure 7: Extended Communication/Power Header Pin 1 2 3 4 Function Vcc Rx (SCL) Tx (SDA) Gnd The Extended Communication/Power Header provides a standard connector for interfacing to the LK2047T-1U. Voltage is applied through pins one and four of the four pin Communication/Power Header. Please ensure the correct voltage input for your display by referencing Voltage Specifications before connecting power. Pins two and three are reserved for serial transmission, using either the RS-232/TTL or clocking data through the I²C protocol, depending on what has been selected by the Protocol Select Jumpers. The versatile Tyco 640456-4-LF style header used can be mated to a number of connectors, the Molex 22-01-3047 for example. Serial DB9 Connector Table 5: Serial DB9 Pinout Pin 2 3 5 9 Function Tx Rx Gnd NC/Vcc* Figure 8: Serial DB9 Connector The LK204-7T-1U provides a DB-9 Connector to readily interface with serial devices using EIA232 standard signal levels. It is also possible to communicate at TTL levels of 0 to +5V by setting the Protocol Select Jumpers to TTL. As an added feature it is also possible to apply power through pin 9 of the DB-9 Connector in order to reduce cable clutter. A standard male DB9 header will provide the perfect mate for this connector. *Note: Do not apply voltage through pin 9 of the DB-9 Connector AND through the Communication/Power Header at the same time. 12 Power Through DB9 Jumper In order to provide power through pin 9 of the DB-9 Connector you must connect the Power Through DB-9 Jumper labelled with white brackets, as illustrated below. This connection can be made using a zero ohm resistor, recommended size 0603, or a solder bridge. The LK204-7T-1U allows all voltage models to use the power through DB-9 option, see the Voltage Specifications for power requirements. Figure 9: Power Through DB9 Jumper Protocol Select Jumpers The Protocol Select Jumpers provide the means necessary to toggle the LK204-7T-1U between RS-232, TTL and I²C protocols. As a default, the jumpers are set to RS-232 mode with solder jumps on the RS232 jumpers. In order to place the display module in I²C mode you must first remove the solder jumps from the RS232 jumpers and then place them on the I2C jumpers. The display will now be in I²C mode and have a default slave address of 80, unless changed with the appropriate command. Similarly, in order to change the display to TTL mode, simply remove the zero ohm resistors from the RS232 or I²C jumpers and solder them to the TTL jumpers. 13 4.2 USB Model Mini USB Connector Table 6: Mini USB Pinout Figure 10: Mini USB Connector Pin 1 2 3 5 Function Vcc DD+ Gnd The LK204-7T-1U-USB comes with a familiar Mini USB Connector to fulfill both communication and power needs. The standard MiniB style header can be connected to any other USB style using the appropriate cable. Most commonly used with a PC, this connection creates a virtual com port that offers a simple power solution with a familiar communication scheme. Alternate USB Header Some advanced applications may prefer the straight four pin connection offered through the Optional Alternate USB Header. This header offers power and communication access in a simple interface package. The Optional Alternate USB Header may be added to the LK204-7T-1U-USB for an added charge as part of a custom order. Please use the Contact section to request more information from the friendly Matrix Orbital sales team. Alternate Power Connector Table 7: Alternate Power Pinout Figure 11: Alternate Power Connector Pin 1 2 3 4 Function Vcc Gnd Gnd NC The Alternate Power Connector provides the ability to power the LK204-7T-1U-USB using a second cable. The Tyco 171825-4 style header is particularly useful for connecting to an unmodified floppy power cable, a 171822-4 for example, from a PC power supply for a simple bench power solution. 14 4.3 Common Features General Purpose Outputs Table 8: GPO Pinout Figure 12: GPO Header Pin 1 2 3 4 5 Function GPO 1 GPO 2 GPO 3 NC Gnd Pin 6 7 8 9 10 Function Vcc Vcc Vcc Vcc Vcc A unique feature of the LK204-7T-1U is the ability to control relays* and other external devices using either one or six General Purpose Outputs. Each can source up to 10mA of current at five volts when on or sink 20mA at zero volts when off. The two row, fourteen pin header can be interfaced to a number of female connectors to provide control to any peripheral devices required. *Note: If connecting a relay, be sure that it is fully clamped using a diode and capacitor in order to absorb any electro-motive force (EMF) which will be generated. Dallas One-Wire Connector Table 9: Dallas One-Wire Pinout Figure 13: Dallas One-Wire Connector Pin 1 2 3 Function Vcc D Gnd In addition to the six general purpose outputs the LK204-7T-1U offers an Optional Dallas One-Wire bridge, to allow for an additional thirty two one-wire devices to be connected to the display. This header can be populated with a Tyco 173979 connector at an added cost by custom order only. Please use the Contact section to request more information from the Matrix Orbital sales team. 15 5 Troubleshooting 5.1 Power In order for your Matrix Orbital Display to function correctly, it must be supplied with the appropriate power. If the backlight is not illuminated, power may not be applied correctly. Try the tips below.     First, check the power cable which you are using for continuity. If you don't have an ohm meter, try using a different power cable, if this does not help try using a different power supply. If power is applied through the DB9 connector, ensure that the Power Through DB9 Jumper is connected. If changes have been made to the protocol select block, ensure all the appropriate protocol select jumpers are connected and all unused protocol jumpers are disconnected. The last step will be to check the interface connector in use on your display. If the power connections have become loose, or you are unable to resolve the issue, please Contact Matrix Orbital for more information. 5.2 Display If your display is powered successfully, the Matrix Orbital logo, or user created screen should display on start up. If this is not the case, check out these tips. • • Ensure the contrast is not too high or too low. This can result in a darkened or blank screen respectively. See the Manual Override section to reset to default. Make sure that the start screen is not blank. It is possible to overwrite the Matrix Orbital logo start screen, if this happens the screen may be blank. Try writing to the display to ensure it is functional, after checking the contrast above. 16 5.3 Communication When communication of either text or commands is interrupted, try the steps below. • • • • • • • • First, check the communication cable for continuity. If you don't have an ohm meter, try using a different communication cable. If you are using a PC try using a different Com/USB Port. Next, please ensure that the display module is set to communicate on the protocol that you are using, by checking the Protocol Select Jumpers. In serial and USB protocols, ensure that the host system and display module are both communicating on the same baud rate. The default rate for the display module is 19200 bps. Match Rx from your display to the transmitting pin from your host and the Tx pin to the receiving pin. If you are communicating to the display via I²C* please ensure that the data is being sent to the correct address. The default slave address for the display module is 80. In I2C mode, connect Rx to the clock line of your controller and Tx to the data output. Unlock the display. See the Set and Save Data Lock command for more info. Finally, you may reset the display to its default settings using the Manual Override procedure outlined below. *Note: I²C communication will always require pull up resistors on SCL and SDA of one to ten kilohms. 5.4 Manual Override Should the settings of your display become altered in a way that dramatically impacts usability, the default settings can be temporarily restored. To override the display, please follow the steps below. 1. 2. 3. 4. Disconnect power from your display. Hold down the bottom left dot key. Reconnect power to your unit, and wait for the start screen before releasing the key. Settings will be temporarily** overridden to the defaults listed in the Manual Override Settings table. At this point any important settings, such as contrast, backlight, or baud rate, should not only be set but saved so they remain when the override is removed. Parameter Backlight Contrast Baud Rate 2 I C Address Value 255 128 19200 80 Table 10: Manual Override Settings **Note: The display module will revert back to the old settings once turned off, unless desired settings are saved. 17 6 Commands 6.1 Communication 1.1 Change Baud Rate Dec 254 57 Speed Hex FE 39 Speed ASCII ■ 9 Speed Immediately changes the baud rate. Not available in I2C. Baud rate can be temporarily forced to 19200 by a manual override. Speed Byte Valid settings shown below. v5.0 Table 11: Accepted Baud Rate Values Rate Speed 1200 83 2400 41 4800 207 9600 103 19200 51 28800 34 38400 25 57600 16 *76800 12 *115200 8 *Note: Baud rates 76800 and 115200 added after firmware revision 5.0 was released as per PCN 2006-08-2 2 1.2 Change I C Slave Address Dec 254 51 Address v5.0 Hex FE 33 Address ASCII ■ 3 Address 2 Immediately changes the I C write address. Only even values are permitted as the next odd address will become the read address. Default is 80. Address Byte Even value. 1.3 Transmission Protocol Select Dec 254 160 Protocol v5.0 Hex FE A0 Protocol ASCII ■ á Protocol Selects the protocol used for data transmission from the display. Data transmission to the display is not affected. Must be set to the protocol in use to receive data correctly. 2 Protocol Byte 1 for Serial (RS232/RS422/TTL/USB) or 0 for I C. 1.4 Set a Non-Standard Baud Rate Dec 254 164 Speed v5.0 Hex FE A4 Speed ASCII ■ ñ Speed Immediately changes the baud rate to a non-standard value. Baud must be a whole number between 977 and 153800. Due to rounding, error increases with baud rate, actual baud must be within 3% of desired baud to ensure accurate communication. Not available in I2C. Can be temporarily forced to 19200 by a manual override. Speed Short Calculations shown below, standard crystal speed is 16MHz. 𝑆𝑝𝑒𝑒𝑑 = 𝐶𝑟𝑦𝑠𝑡𝑎𝑙𝑆𝑝𝑒𝑒𝑑 −1 (8 × 𝐷𝑒𝑠𝑖𝑟𝑒𝑑𝐵𝑎𝑢𝑑) Equation 1: Speed Byte Calculation 𝐴𝑐𝑡𝑢𝑎𝑙𝐵𝑎𝑢𝑑 = 𝐶𝑟𝑦𝑠𝑡𝑎𝑙𝑆𝑝𝑒𝑒𝑑 (8 × (𝑆𝑝𝑒𝑒𝑑 + 1)) Equation 2: Actual Baud Rate Calculation |𝐷𝑒𝑠𝑖𝑟𝑒𝑑𝐵𝑎𝑢𝑑 − 𝐴𝑐𝑡𝑢𝑎𝑙𝐵𝑎𝑢𝑑| < 0.03 𝐷𝑒𝑠𝑖𝑟𝑒𝑑𝐵𝑎𝑢𝑑 Equation 3: Baud Rate Error Calculation 18 6.2 Text 2.1 Clear Screen Dec 254 88 Hex FE 58 ASCII ■X Clears the contents of the screen. v5.0 2.2 Change the Start Up Screen Dec 254 64 Characters v5.0 Hex FE 40 Characters ASCII ■ @ Characters Changes the message displayed on start up. Custom characters can be included by adding their decimal value (07). Characters will automatically wrap on the display. Characters 80 bytes, space characters can be added as needed 2.3 Auto Scroll On Dec 254 81 v5.0 Hex FE 51 ASCII ■Q The entire contents of screen are shifted up one line when the end of the screen is reached. Display default is on. 2.4 Auto Scroll Off Dec 254 82 v5.0 Hex FE 52 ASCII ■R New text is written over the top line when the end of the screen is reached. Display default is Auto Scroll on. 2.5 Set Auto Line Wrap On Dec 254 67 Hex FE 43 ASCII ■C Text will wrap to the next consecutive line once a row becomes full. Default is Auto Line Wrap on. v5.0 2.6 Set Auto Line Wrap Off Dec 254 68 v5.0 Hex FE 44 ASCII ■D Text will skip one line when wrapping once a row becomes full. Writing order will be rows 1, 3, 2, and then 4. Default is Auto Line Wrap on. 2.7 Set Cursor Position Dec 254 71 Column Row Hex FE 47 Column Row ASCII ■ G Column Row Sets the cursor to a specific cursor position where the next transmitted character is printed. Column Byte Value between 1 and number of character columns. Row Byte Value between 1 and number of character rows. 19 v5.0 2.8 Go Home Dec 254 72 Hex FE 48 ASCII ■H Returns the cursor to the top left of the screen. v5.0 2.9 Move Cursor Back Dec 254 76 Hex FE 4C ASCII ■L Moves cursor one position to the left. Cursor will obey wrap settings. v5.0 2.10 Move Cursor Forward Dec 254 77 Hex FE 4D ASCII ■M Moves cursor one position to the right. Cursor will obey wrap settings. v5.0 2.11 Underline Cursor On Dec 254 74 Hex FE 4A ASCII ■J Displays a line under the current cursor position. Can be used with block cursor. v5.0 2.12 Underline Cursor Off Dec 254 75 Hex FE 4B ASCII ■K Removes line under current cursor position. v5.0 2.13 Blinking Block Cursor On Dec 254 83 Hex FE 53 ASCII ■S Displays a blinking block over the current cursor position. Can be used with underline. v5.0 2.14 Blinking Block Cursor Off v5.0 Dec 254 84 Hex FE 54 ASCII ■T Removes blinking block over current cursor position. 20 6.3 Special Characters 3.1 Create a Custom Character Dec 254 78 ID Data v5.0 Hex FE 4E ID Data ASCII ■ N ID Data Creates a custom character. Each character is divided into 8 rows of 5 pixels; each data byte represents one row. Each byte is padded by three zero bits followed by five bits representing each pixel state. A one represents an on condition while a zero is off. Characters are lost when a new memory bank is loaded, unless they are saved. ID Byte Character ID, value between 0 and 7. Data Byte[8] Character pixel data as shown below. Table 12: Custom Degree Character Data[1] 000 p1 p2 p3 p4 p5 00001000 8 Data[2] 000 p1 p2 p3 p4 p5 00010100 20 Data[3] 000 p1 p2 p3 p4 p5 00001000 8 Data[4] 000 p1 p2 p3 p4 p5 00000011 3 Data[5] 000 p1 p2 p3 p4 p5 00000100 4 Data[6] 000 p1 p2 p3 p4 p5 00000100 4 Data[7] 000 p1 p2 p3 p4 p5 00000011 3 Data[8] 000 p1 p2 p3 p4 p5 00000000 0 3.2 Save Custom Characters Dec 254 193 Bank ID Data v5.0 Hex FE C1 Bank ID Data ASCII ■ ñ Bank ID Data Provides access to all memory banks to create and save custom characters, graph bars, and large digits. Any new characters saved will overwrite the old, so care should be taken when writing to any bar or digit memory bank. Bank structure is shown below. Bank Byte 1 byte, memory bank ID, value between 0 and 4, as below. ID Byte 1 byte, value between 0 and 7. Data Byte[8] 8 bytes, character pixel data as above. Table 13: Custom Character Banks 0 Start-up Characters 3.3 Load Custom Characters 1 Horizontal Bars 2 Vertical Bars 3 Medium Digits 4 Large Digits Dec 254 192 Bank Hex FE C0 Bank ASCII ■ └ Bank Loads a bank of custom characters into memory for use. Must be issued before using a bank of characters. Alternatively, an appropriate initialize command can be used. Bank Byte Memory bank ID, value between 0 and 4, as above. 21 v5.0 3.4 Save Start Up Dec 254 194 ID Data v5.0 Screen Custom Hex FE C2 ID Data ■ ┬ ID Data Characters ASCII Saves a custom character to memory for the start up screen or repeated use. Start up characters are displayed by sending their ID to the screen. ID Byte Value between 0 and 7. Data Byte[8] Character pixel data, see Custom Degree Character example. 3.5 Initialize Medium Numbers Dec 254 109 v5.0 Hex FE 6D ASCII ■m Loads the medium number custom character bank into memory. Medium numbers must be initialized before use. 3.6 Place Medium Numbers Dec 254 111 Row Column Digit v5.0 Hex FE 6F Row Column Digit ASCII ■ o Row Column Digit Places a single medium decimal digit of 2 row height and 1 column width on the display at the position specified. Medium numbers must be initialized before being placed. Row Byte Value between 1 and 20. Column Byte Value between 1 and 4. Digit Byte Single decimal digit to display. 3.7 Initialize Large Numbers Dec 254 110 Hex FE 6E ASCII ■n Loads the large number custom character bank into memory. Large numbers must be initialized before use. v5.0 3.8 Place Large Numbers Dec 254 35 Column Digit v5.0 Hex FE 23 Column Digit ASCII ■ # Column Digit Places a single large decimal digit, 4 rows in height and 3 columns in width, on the display at the position specified. Medium numbers must be initialized before being placed. Column Byte Value between 1 and 20. Digit Byte Single decimal digit to display. 3.9 Initialize Horizontal Bar Dec 254 104 v5.0 Hex FE 68 ASCII ■h Loads the horizontal bar graph custom character bank into memory. Horizontal bar characters must be initialized before a graph is displayed. 22 3.10 Place Horizontal Bar Graph Dec 254 124 Column Row Direction Length v5.0 Hex FE 7C Column Row Direction Length ■ | Column Row Direction Length ASCII Places a horizontal bar graph on the screen beginning at the column and row specified. The bar extends either right or left to the length indicated. New bars will overwrite old. Column Byte 1 byte, value between 1 and 20 Row Byte 1 byte, value between 1 and 4 Direction Byte 1 byte, 0 for right and 1 for left Length Byte 1 byte, length in pixels of the graph, value between 0 and 100 3.11 Initialize Narrow Vertical Bar Dec 254 115 Hex FE 73 ASCII ■s Loads the narrow horizontal bar graph custom character bank into memory. A narrow bar is 2 pixels wide. Horizontal bar characters must be initialized before a graph is displayed. v5.0 3.12 Initialize Wide Vertical Bar Dec 254 118 v5.0 Hex FE 76 ASCII ■v Loads the wide horizontal bar graph custom character bank into memory. A wide bar is 5 pixels wide. Horizontal bar characters must be initialized before a graph is displayed. 3.13 Place Vertical Bar Dec 254 61 Column Length v5.0 Hex FE 3D Column Length ASCII ■ = Column Length Places a vertical bar graph on the screen extending from the first row of the column specified. The bar extends upwards to the length indicated. A new bar will over write the old. Column Byte Value between 1 and 20. Length Byte Height in pixels of the graph, value between 0 and 32. 23 6.4 General Purpose Output 4.1 General Purpose Output On Dec 254 87 Number Hex FE 57 Number ASCII ■ W Number Turns the specified GPO on, sinking current to an output of zero volts. Number Byte GPO to be turned on. v5.0 4.2 General Purpose Output Off v5.0 Dec 254 86 Number Hex FE 56 Number ASCII ■ V Number Turns the specified GPO off, sourcing current from an output of five volts. Number Byte GPO to be turned off. 4.3 Set Start Up GPO State Dec 254 195 Number State v5.0 Hex FE C3 Number State ■ ├ Number State ASCII Sets and saves the start up state of the specified GPO in non volatile memory. Changes will be seen on start up. Number Byte GPO to be controlled. State Byte 1 for on or 0 for off. LED Indicators The LK204-7T-1U has 6 General Purpose Outputs which control 3 bi-colour LEDs. Red, green, and orange-yellow colours can be created using these software controlled GPOs. Odd numbered GPOs control red while even numbers switch the green aspects of the LEDs, as shown in the table below. Table 14: LED Output LED 1 2 3 GPO 1 2 3 4 5 6 Yellow On On On On On On Green Off On Off On Off On Red On Off On Off On Off Off Off Off Off Off Off Off Figure 14: LED Location 24 6.5 Dallas One-Wire 5.1 Search for a One-Wire Device Dec 254 200 2 v5.0 Hex FE C8 02 ■ ╚ SOT ASCII Sends a search query to each of the up to 32 devices on the one wire bus. Any connected device will respond with an identification packet. Response Bytes [14] Dallas One-Wire identification packet as shown below. Table 15: Dallas One-Wire Packet Information Offset 0 Length 2 2 1 3 4 5 13 1 1 8 1 Value 9002 138 10 49 0 0 Description Preamble Another device packet will follow OR Last device packet Packet Type Error Code (0 indicates success) Device Address CRC8 address check (0 indicates validity) 5.2 Dallas One-Wire Transaction Dec 254 200 1 Flags Send Bits Receive Bits Data v5.0 Hex FE C8 01 Flags Send Bits Receive Bits Data ■ ╚ STX Flags Send Bits Receive Bits Data ASCII Performs a single Dallas 1-Wire transaction. Consult your device documentation for information regarding device specific protocols. If an error is encountered, a corresponding value will be returned by the device. Flags Byte Flags for transaction, see below. Send Bits Byte Number of bytes to be sent to the device. Receive Bits Byte Number of bytes expected to be received from the device. Data Byte(s) Data to be transmitted LSB to MSB. Table 16: Dallas One-Wire Flags Bit 7 6 5 4 3 2 1 0 25 Flag Description Unused 0 (Future Compatibility) Add CRC8 to transaction 0 (Future Compatibility) Read CRC8 from transaction Reset Bus prior to transaction Table 17: Dallas One-Wire Errors Code 0 1 2 3 Error Description Success Unknown Command No Devices Found Fatal Search Error 6.6 Keypad 6.1 Auto Transmit Key Presses On Dec 254 65 Hex FE 41 ASCII ■A Key presses are automatically sent to the host when received by the display. Default is Auto Transmit on. v5.0 6.2 Auto Transmit Key Presses Off Dec 254 79 v5.0 Hex FE 4F ASCII ■O Key presses are held in the 10 key buffer to be polled by the host using the Poll Key Press command. Use this mode for I2C transactions. Default is Auto Transmit on. 6.3 Poll Key Press Dec 254 38 v5.0 Hex FE 26 ASCII ■& Reads the last unread key press from the 10 key display buffer. If another key is stored in the buffer the MSB will be 1, the MSB will be 0 when the last key press is read. If there are no stored key presses a value of 0 will be returned. Auto transmit key presses must be turned off for this command to be successful. Response Byte Value of key pressed (MSb determines additional keys to be read). 6.4 Clear Key Buffer Dec 254 69 Hex FE 45 ASCII ■E Clears all key presses from the key buffer. v5.0 6.5 Set Debounce Time Dec 254 85 Time v5.0 Hex FE 55 Time ASCII ■ U Time Sets the time between a key press and a key read by the display. Most switches will bounce when pressed; the debounce time allows the switch to settle for an accurate read. Default is 8 representing approximately 52ms. Time Byte Debounce increment (debounce time = Time * 6.554ms). 6.6 Set Auto Repeat Mode Dec 254 126 Mode v5.0 Hex FE 7E Mode ■ DEL Mode ASCII Sets key press repeat mode to typematic or hold. In typematic mode if a key press is held, the key value is transmitted immediately, then 5 times a second after a 1 second delay. In hold mode, the key down value is transmitted once when pressed, and then the key up value is sent when the key is released. Default is typematic. Mode Byte 1 for hold mode or 0 for typematic. 26 6.7 Auto Repeat Mode Off Dec 254 96 Hex FE 60 ■` ASCII Turns auto repeat mode off. Default is on (typematic). v5.0 6.8 Assign Keypad Codes Dec 254 213 Key Down Key Up v5.0 Hex FE D5 Key Down Key Up ■ ╒ Key Down Key Up ASCII Assigns the key down and key up values sent to the host when a key press is detected. A key up and key down value must be sent for every key, a value of 255 will leave the key unaltered. Defaults are shown below. Key Down Bytes [25] Key down values, beginning at row one column one moving right then down. Key Up Bytes [25] Key up values, beginning at row one column one moving right then down. Figure 15: Default Tactile Key Down Values Figure 16: Default Tactile Key Up Values *Note: Values are not mapped to a physical key. 6.9 Keypad Backlight Off Dec 254 155 Hex FE 9B ■¢ ASCII Turns the keypad backlight off. v5.0 6.10 Set Keypad Brightness v5.0 Dec 254 156 Brightness Hex FE 9C Brightness ■ £ Brightness ASCII Immediately sets the keypad brightness. On time is set using the Backlight On command. Default is 255. Brightness Byte Brightness level from 0(Dim) to 255(Bright). 27 6.11 Set Auto Backlight Dec 254 157 Setting v5.0 Hex FE 9D Setting ■ ¥ Setting ASCII Set the way the display and keypad backlights respond when a key is pressed. The options in the tables below allow a keypress to turn on the display and/or keypad backlights after they have timed out or been turned off. Setting Byte What portions of the unit light on a keypress, if any, and if that press is returned. Table 18: AutoBacklight Settings 0 1 2 3 Transmit First Keypress No Lighting Change Light Keypad Backlight Light Display Backlight Light Keypad and Display 8 9 10 11 Omit First Keypress No Lighting Change Light Keypad Backlight Light Display Backlight Light Keypad and Display 6.7 Display Functions 7.1 Backlight On Dec 254 66 Minutes v5.0 Hex FE 42 Minutes ASCII ■ B Minutes Turns the display backlight on for a specified length of time. If an inverse display color is used this command will essentially turn on the text. Minutes Byte Number of minutes to leave backlight on, a value of 0 leaves the display on indefinitely. 7.2 Backlight Off Dec 254 70 Hex FE 46 ASCII ■F Turns the display backlight off. If an inverse display colour is used this command will turn off the text. v5.0 7.3 Set Brightness v5.0 Dec 254 153 Brightness Hex FE 99 Brightness ASCII ■ Ö Brightness Immediately sets the backlight brightness. If an inverse display color is used this represents the text colour intensity instead. Default is 255. Brightness Byte Brightness level from 0(Dim) to 255(Bright). 7.4 Set and Save Brightness Dec 254 152 Brightness v5.0 Hex FE 98 Brightness ASCII ■ ÿ Brightness Immediately sets and saves the backlight brightness. Although brightness can be changed using the set command, it is reset to this saved value on start up. Default is 255. Brightness Byte Brightness level from 0(Dim) to 255(Bright). 28 7.5 Set Backlight Colour Dec 254 130 Red Green Blue Hex FE 82 Red Green Blue ■ é Red Green Blue ASCII Set the colour of a tri-colour backlight. Only for tri-colour displays. Default is white (255, 255, 255). Red Byte Brightness level of Red from 0(Dim) to 255(Bright). Green Byte Brightness level of Green from 0(Dim) to 255(Bright). Blue Byte Brightness level of Blue from 0(Dim) to 255(Bright). v5.0 7.6 Set Contrast Dec 254 80 Contrast v5.0 Hex FE 50 Contrast ASCII ■ P Contrast Immediately sets the contrast between background and text. If an inverse display color is used this also represents the text brightness. Default is 128. Contrast Byte Contrast level from 0(Light) to 255(Dark). 7.7 Set and Save Contrast Dec 254 145 Contrast v5.0 Hex FE 91 Contrast ASCII ■ æ Contrast Immediately sets and saves the contrast between background and text. Although contrast can be changed using the set command, it is reset to this saved value on start up. Default is 128. Contrast Byte Contrast level from 0(Light) to 255(Dark). 6.8 Data Security 8.1 Set Remember Dec 254 147 Switch v5.0 Hex FE 93 Switch ASCII ■ ô Switch Allows changes to specific settings to be saved to the display memory. Writing to non-volatile memory can be slow and each change consumes 1 write of at least 100,000 available. The Command Summary outlines which commands are saved always, never, and when this command is on only. Remember is off by default. Switch Byte 1 for on or 0 for off. 8.2 Set Data Lock Dec 254 202 245 160 Level v5.0 Hex FE CA F5 A0 Level ASCII ■ ╩ ⌡ á Level Temporarily locks certain aspects of the display to ensure no inadvertent changes are made. The lock is released after a power cycle. A new level overrides the old, and levels can be combined. Default is 0. Level Byte Lock level, see Data Lock Bits table. Table 19: Data Lock Bits Display 7 29 Command 6 Reserved 5 Setting 4 Address 3 Reserved 2 Reserved 1 Reserved 0 Table 20: Lock Parameters Reserved Address Setting Command Display Place holders only, should be 0 Locks the Baud Rate and I2C address Locks all settings from being saved Locks all commands, text can still be written Locks entire display, no new text can be displayed 8.3 Set and Save Data Lock Dec 254 203 245 160 Level v5.0 Hex FE CB F5 A0 Level ASCII ■ ╦ ⌡ á Level Locks certain aspects of the display to ensure no inadvertent changes are made. The lock is not affected by a power cycle. A new level overrides the old, and levels can be combined. Default is 0. Level Byte See Data Lock Bits table. 6.9 Miscellaneous 9.1 Write Customer Data Dec 254 52 Data v5.0 Hex FE 34 Data ASCII ■ 4 Data Saves a user defined block of data to non-volatile memory. Useful for storing display information for later use. Data Byte [16] User defined data. 9.2 Read Customer Data Dec 254 53 v5.0 Hex FE 35 ASCII ■5 Reads data previously written to non-volatile memory. Data is only changed when written, surviving power cycles. Response Byte [16] Previously saved user defined data. 9.3 Read Version Number Dec 254 54 Hex FE 36 ASCII ■6 Causes display to respond with its firmware version number. Test. Response Byte Convert to hexadecimal to view major and minor revision numbers. v5.0 9.4 Read Module Type v5.0 Dec 254 55 Hex FE 37 ASCII ■7 Causes display to respond with its module number. Response Byte Module number, see Sample Module Type Responses for a partial list. Table 21: Sample Module Type Responses 2B LK204-7T-1U 2C LK204-7T-USB 30 7 Appendix 7.1 Command Summary Available commands below include identifying number, required parameters, the returned response and an indication of whether settings are remembered always, never, or with remember set to on. Table 22: Communication Command Summary Name Change Baud Rate 2 Change I C Slave Address Transmission Protocol Select Set a Non-Standard Baud Rate Dec 57 51 160 164 Hex 39 33 A0 A4 ASCII 9 3 á ñ Parameters Byte Byte Byte Short Response None None None None Remembered Always Always Remember On Always Table 23: Text Command Summary Name Clear Screen Change the Start Up Screen Auto Scroll On Auto Scroll Off Set Auto Line Wrap On Set Auto Line Wrap Off Set Cursor Position Go Home Move Cursor Back Move Cursor Forward Underline Cursor On Underline Cursor Off Blinking Block Cursor On Blinking Block Cursor Off 31 Dec 88 64 81 82 67 68 71 72 76 77 74 75 83 84 Hex 58 40 51 52 43 44 47 48 4C 4D 4A 4B 53 54 ASCII X @ Q R C D G H L M J K S T Parameters None Byte[] None None None None Byte[2] None None None None None None None Response None None None None None None None None None None None None None None Remembered Never Always Remember On Remember On Remember On Remember On Never Never Never Never Remember On Remember On Remember On Remember On Table 24: Special Character Command Summary Name Create a Custom Character Save Custom Characters Load Custom Characters Save Start Up Screen Custom Characters Initialize Medium Numbers Place Medium Numbers Initialize Large Numbers Place Large Numbers Initialize Horizontal Bar Place Horizontal Bar Graph Initialize Narrow Vertical Bar Initialize Wide Vertical Bar Place Vertical Bar Dec 78 193 192 Hex 4E C1 C0 ASCII N ñ └ Parameters Byte[9] Byte[10] Byte Response None None None Remembered Remember On Always Never 194 C2 ┬ Byte[9] None Always 109 111 110 35 104 124 115 118 61 6D 6F 6E 23 68 7C 73 76 3D m o n # h | s v = None Row, Col, Digit None Col, Digit None Col, Row, Dir, Length None None Col, Length None None None None None None None None None Never Never Never Never Never Never Never Never Never Table 25: General Purpose Output Command Summary Name General Purpose Output On General Purpose Output Off Set Start Up GPO State Dec 86 87 195 Hex 56 57 C3 ASCII V W ├ Parameters Byte Byte Byte[2] Response None None None Remembered Never Never Always Table 26: Dallas One-Wire Command Summary Name Search for a One-Wire Device Dallas One-Wire Transaction Dec 200, 2 200, 1 Hex C8, 02 C8, 01 ASCII ╚, SOT ╚, STX Parameters None Byte[3], Byte[] Response Byte[14] Byte[] Remembered Never Never Response None None Byte None None None None None None None None Remembered Remember On Remember On Never Never Remember On Remember On Remember On Always Never Remember On Always Table 27: Keypad Command Summary Name Auto Transmit Key Presses On Auto Transmit Key Presses Off Poll Key Press Clear Key Buffer Set Debounce Time Set Auto Repeat Mode Auto Repeat Mode Off Assign Keypad Codes Keypad Backlight Off Set Keypad Brightness Set Auto Backlight Dec 65 79 38 69 85 126 96 213 155 156 157 Hex 41 4F 26 45 55 7E 60 D5 98 9C 9D ASCII A ` & E U DEL ` ╒ ¢ £ ¥ Parameters None None None None Byte Mode None Byte[25], Byte[25] None Byte Byte 32 Table 28: Display Functions Command Summary Name Backlight On Backlight Off Set Brightness Set and Save Brightness Set Backlight Colour Set Contrast Set and Save Contrast Dec 66 70 153 152 130 80 145 Hex 42 46 99 98 82 50 91 ASCII B F Ö ÿ é P æ Parameters Byte None Byte Byte Byte[3] Byte Byte Response None None None None None None None Remembered Remember On Remember On Remember On Always Remember On Remember On Always Table 29: Data Security Command Summary Name Set Remember Set Data Lock Set and Save Data Lock Dec 147 202, 245, 160 203, 245, 160 Hex 93 CA, F5, A0 CB, F5, A0 ASCII ô ╩, ⌡, á ╦, ⌡, á Parameters Byte Byte Byte Response None None None Remembered Always Remember On Always Table 30: Miscellaneous Command Summary Name Write Customer Data Read Customer Data Read Version Number Read Module Type 33 Dec 52 53 54 55 Hex 34 35 36 37 ASCII 4 5 6 7 Parameters Byte[16] None None None Response None Byte[16] Byte Byte Remembered Always Never Never Never 7.2 Character Sets Figure 17: LK204-7T-1U Japanese Character Set 34 7.3 Environmental Specifications Table 31: Environmental Limits Operating Temperature Storage Temperature Operating Relative Humidity Thermal Shock Standard Extended (-E) 0°C to +50°C -20°C to +70°C -10°C to +60°C -30°C to +80°C Maximum 90% non-condensing Maximum 10°C /min 7.4 Electrical Tolerances Current Consumption Table 32: Current Consumption Board 60mA + Backlight 50 to 200 mA GPOs 20mA each maximum + Table 33: Backlight Current Draw YG 100mA GW & WB 50mA TCI 200mA Input Voltage Specifications Table 34: Voltage Specifications Low Voltage (-LV) 3.3V Standard* 4.75-5.25V 7.5 Optical Characteristics Table 35: Display Optics Module Size Viewing Area Active Area Character Size Character Pitch Pixel Size Pixel Pitch Viewing Direction Viewing Angle Contrast Ratio Backlight Half-Life (YG) Backlight Half-Life (GW & WB) Backlight Half-Life (TCI) 35 LCD Model 142.00 x 38.00 x 36.0 82.0 x 36.0 77.0 x 23.6 3.20 x 5.15 3.90 x 6.15 0.60 x 0.60 0.65 x 0.65 12 -30 to +30 3 50,000 20,000 10,000 mm mm mm mm mm mm mm O’clock ° Hours Hours Hours 7.6 Dimensional Drawings Figure 18: Display Dimensional Drawing Figure 20: USB Model Drawing 36 Figure 19: Standard Model Drawing 8 Ordering 8.1 Part Numbering Scheme Table 36: Part Numbering Scheme LK 1 -204 2 -7T 3 -1U 4 -USB 5 -TCI 6 7 -E 8 8.2 Options Table 37: Display Options # 1 2 3 4 Designator Product Type Display Size Keypad Size Form Factor 5 Protocol 6 Colour 7 Voltage 8 Temperature Options LK: Liquid Crystal Display with Keypad Input -204: 20 Columns by 4 Rows -7T: Seven Integrated Tactile Keys -1U: Fits a 1U Opening NP*: Standard Model -USB: USB Only Model -YG: Black Text with Yellow-Green Background -GW: Grey Text with Grey-White Background -WB: White Text with Blue Background -TCI: Tricolour Text with Black Background -LV: Low Voltage (3.3V) NP*: Standard Voltage (4.75-5.25V) NP*: Standard -E: Extended Temperature *Note: NP means No Populate; skip this designator in the part number and move to the next option. 37 8.3 Accessories Power Table 38: Power Accessories PCS Standard Power Cable Communication Table 39: Communication Accessories CSS4FT 4 ft. Serial Cable EXTMUSB3FT Mini-USB Cable INTMUSB3FT Internal Mini-USB Cable SCCPC5V Serial Communication/5V Power Cable BBC Breadboard Cable 38 Peripherals Table 40: Peripheral Accessories Temperature Probe Dallas One-Wire Temperature Probe Mounting Table 41: Mounting Accessories B19264-BK 39 Black 7T-1U Mounting Bracket 9 Definitions ASCII: American standard code for information interchange used to give standardized numeric codes to alphanumeric characters. BPS: Bits per second, a measure of transmission speed. DOW: Dallas One-Wire protocol, similar to I2C, provides reduced data rates at a greater distance. One wire carries data, while two others supply power and ground. Matrix Orbital tests non-parasitic devices only, those that do not draw power from the data line; however, some parasitic devices may work. FFSTN: Double film super-twisted nematic in reference to an LCD. The addition of two layers of film between the STN display and polarizer improves contrast. GPO: General purpose output, used to control peripheral devices from a display. GUI: Graphical user interface. Hexadecimal: A base 16 number system utilizing symbols 0 through F to represent the values 0-15. I2C: Inter-integrated circuit protocol uses clock and data lines to communicate short distances at slow speeds from a master to up to 128 addressable slave devices. A display is a slave device. LSB: Least significant bit or byte in a transmission, the rightmost when read. MSB: Most significant bit or byte in a transmission, the leftmost when read. RS232: Recommended standard 232, a common serial protocol. A low level is -30V, a high is +30V. RS422: Recommended standard 422, a more robust differential pair serial protocol. SDA: Serial data line used to transfer data in I2C protocol. This open drain line should be pulled high through a resistor. Nominal values are between 1K and 10K Ω. SCL: Serial clock line used to designate data bits in I2C protocol. This open drain line should be pulled high through a resistor. Nominal values are between 1K and 10K Ω. STN: Super-twisted nematic in reference to an LCD. In a relaxed or nematic state, crystals orientate themselves in the same direction and allow light to pass. In an excited state these crystals align to block light. Super-twisted crystals move from 180 to 270 degrees providing greater contrast than TN models. TTL: Transistor-transistor logic applied to serial protocol. Low level is 0V while high logic is 5V. 10 Contact Sales Support Online Phone: 403.229.2737 Phone: 403.204.3750 Purchasing: www.matrixorbital.com Email: sales@matrixorbital.ca Email: support@matrixorbital.ca Support: www.matrixorbital.ca 40