MDEV-915-250

250 Series Master Development System User's Guide ! Warning: Linx radio frequency ("RF") products may be used to control machinery or devices remotely, including machinery or devices that can cause death, bodily injuries, and/or property damage if improperly or inadvertently triggered, particularly in industrial settings or other applications implicating life-safety concerns. No Linx Technologies product is intended for use in any application without redundancies where the safety of life or property is at risk. The customers and users of devices and machinery controlled with RF products must understand and must use all appropriate safety procedures in connection with the devices, including without limitation, using appropriate safety procedures to prevent inadvertent triggering by the user of the device and using appropriate security codes to prevent triggering of the remote controlled machine or device by users of other remote controllers. Do not use this or any Linx product to trigger an action directly from the data line or RSSI lines without a protocol or encoder/ decoder to validate the data. Without validation, any signal from another unrelated transmitter in the environment received by the module could inadvertently trigger the action. All RF products are susceptible to RF interference that can prevent communication. RF products without frequency agility or hopping implemented are more subject to interference. This module does have a frequency hopping protocol built in, but the developer should still be aware of the risk of interference. Do not use any Linx product over the limits in this data guide. Excessive voltage or extended operation at the maximum voltage could cause product failure. Exceeding the reflow temperature profile could cause product failure which is not immediately evident. Do not make any physical or electrical modifications to any Linx product. This will void the warranty and regulatory and UL certifications and may cause product failure which is not immediately evident. Table of Contents 1^ 2^ 2^ 3^ 3^ 4^ 12^ 13^ 14^ 15^ 21^ 21^ 23^ Introduction Ordering Information 250 Series Transceiver Development Board 250 Series Transceiver Evaluation Module Using the Development Boards Using the Development Boards Troubleshooting The Prototyping Area Range Testing Master Development Software About Antennas In Closing 250 Series Master Development Board Schematic 250 Series Master Development System User's Guide Figure 1: 250 Series Master Development System Introduction The Linx 250 Series RF modules offer a simple, efficient and cost-effective method of adding wireless communication capabilities to any product. The Master Development System gives a designer all the tools necessary to correctly and legally incorporate the 250 Series into an end product. The development boards serve several important functions: • Rapid Module Evaluation: The boards allow the performance of the 250 Series modules to be quickly evaluated in a user’s environment. • Range Testing: Windows-based demonstration software is included, which allows for a variety of tests. A pair of development boards can be used to evaluate the range performance of the modules. • Design Benchmark: The boards provide a known benchmark against which the performance of a custom design may be judged. • Application Development: An onboard prototyping area allows for the development of custom circuits directly on the development board. All signal lines are available on a header for easy access. The Master Development System includes two development boards, two 250 Series evaluation modules, two 250 Series transceivers, two CW Series antennas, two RH Series antennas, six AAA batteries, USB cables, demonstration software and full documentation. – 1 – Revised 2/7/14 Ordering Information Ordering Information Part Number Description MDEV-915-250 250 Series Master Development System Figure 2: Ordering Information 250 Series Transceiver Development Board 3 4 1 2 5 6 9 10 8 11 Figure 3: 250 Series Transceiver Development Board 1. 2. 3. 4. 5. 6. Prototyping Area Batteries (3xAAA) On-Off Switch Power LED USB Connector USB Jumpers 7. RS-232 Connector 8. RS-232 Jumpers 9. Breakout Header 10. EVM Module Socket 11. Serial Port Indicators –2 – 7 250 Series Transceiver Evaluation Module Figure 4: 250 Series Transceiver Evaluation Module Using the Development Boards The development system provides a stable platform to test and evaluate the performance of the modules. Everything required for basic testing is included in the box. The system includes two identical development boards and two evaluation modules. These are used to set up a bi-directional data link. The development boards have USB and RS-232 interfaces to connect to computers or peripheral devices. Windows-based software is included that is used to configure the modules and to establish a wireless chat that can send text between the modules. – 3 – Using the Development Boards After unpacking the development system, the following steps are used to get started. 1. Insert an EVM module into the evaluation boards, observing the correct orientation. The antenna connector should be closest to the edge of the development board (Figure 5). Make sure it is seated fully and correctly. Figure 5: 250 Series Transceiver Evaluation Module on the Development Board 2. Screw an antenna onto each EVM board and install the AAA batteries. 3. Set the jumpers on the development boards. If using the USB interface then populate the USB jumpers and remove the RS-232 jumpers (Figure 6 A). If using the RS-232 interface then populate the RS-232 jumpers and remove the USB jumpers (Figure 6 B). Connecting both sets of jumpers at the same time could lead to short circuits and bit collisions, so only use one interface at a time. 4. Connect one of the development boards to a computer. USB drivers are included on the CD, so install them if using the USB interface and prompted by the computer. The latest drivers may be downloaded from Silicon Labs at http://www.silabs.com/products/interface/ usbtouart/Pages/usb-to-uart-bridge.aspx –4 – (A) (B) Figure 6: 250 Series Development Board Jumpers; (A) for USB Interface; (B) for RS-232 Interface 5. Insert the CD that is included with the kit into the computer and install the Windows software. If already installed, skip this step. 6. Run the software, select “Wi.232FHSS-250” and click “OK” (Figure 7 A). On the next screen select the appropriate COM port and 2400 baud operation Then click “OK” (Figure 7 B). Note that if the baud rate has been changed on the module, then the baud rate must be changed here as well. (A) (B) Figure 7: 250 Series Transceiver Development System Software Setup – 5 – 7. The software opens on the Volatile Registers tab. Click on the “Wireless Chat” tab as shown in Figure 8. Figure 8: 250 Series Transceiver Development System Software Volatile Registers Tab This opens the wireless chat window (Figure 9). –6 – Figure 9: 250 Series Transceiver Development System Software Wireless Chat Tab 8. The second board can be connected to the same computer for bench top testing or to a second computer for range testing. Open a second instance of the software if using one computer. If two computers are used then repeat steps 4 through 7 for the second board on the second computer. – 7 – 9. Power-On both development boards, verifying that the version / copyright information is displayed on the screen from both modules (Figure 10). Figure 10: 250 Series Transceiver Development System Software Wireless Chat Tab with Module Information –8 – 10. Type a message into the bottom box in one of the windows. Figure 11: 250 Series Transceiver Development System Software Wireless Chat Tab – 9 – 11. Press Enter and look for the message to appear in the top box of the window connected to the second module (B). It appears in the middle box of the window for the sending module (A). (A) (B) Figure 12: 250 Series Transceiver Development System Software Wireless Chat Tab; (A) Sent; (B) Received –10 – 12. Chat back and forth between evaluation boards, verifying that serial and RF communications are successful. (A) (B) Figure 13: 250 Series Development System Software Wireless Chat Tab; Response (A) Received; (B) Sent – 11 – Troubleshooting If the boards fail to work out of the box, then try the following: • Check the batteries to make sure they are not dead. • Make sure that the antennas are connected. • Make sure that the jumpers are set correctly. • Ensure that the latest USB drivers are installed. • Test additional baud rates. If all of these appear to be in order, then you can call 800-736-6677 or e-mail techsupport@linxtechnologies.com. –12 – The Prototyping Area In addition to their evaluation functions, the boards may also be used for actual product development. They feature a prototyping area for the addition of application-specific circuitry. The prototyping area is the same on both boards and contains a large area of plated through-holes so that external circuitry can be placed on the board. The holes are set at 0.1" on center with a 0.05" diameter, making it easy to add most industry-standard SIP and DIP packages to the board. This circuitry can be interfaced with the transceiver through the breakout header at the bottom. On the right of this area is a row connected to the 3.3V power supply and on the left is a row connected to ground. Note: The on-board 3.3-volt regulator has approximately 50mA of headroom available for additional circuitry. If added circuitry requires a higher current, the user must power the board from an external supply. +3.3 Volt Bus Ground Bus Breakout Header Figure 14: The Development Board Prototyping Area – 13 – Range Testing Several complex mathematical models exist for determining path loss in many environments. These models vary as the transmitter and receiver are moved from indoor operation to outdoor operation. Although these models can provide an estimation of range performance in the field, the most reliable method is to simply perform range tests using the transmitter and receiver in the intended operational environment. Simple range testing can be done with the development boards. Connect one board to a computer and set the software into Wireless Chat. Remove all jumpers from the other board and place one between the RXD0 and TXD0 pins on the breakout header as shown in Figure 15. This routs data received by the module back into its transmit buffer to be sent back to the first unit. In this way one board stays connected to a computer and the other board is moved away to test the effective range of the link. Figure 15: The Development Board Prototyping Area As the maximum range of the link in an area is approached, it is not uncommon for the signal to cut in and out as the transmitter moves. This is normal and can result from other interfering sources or fluctuating signal levels due to multipath. Multipath results in cancellation of the transmitted signal as direct and reflected signals arrive at the receiver at differing times and phases. The areas in which this occurs are commonly called “nulls” and simply walking a little further usually restores the signal. If this does not restore the signal, then the maximum effective range of the link has been reached. To achieve maximum range, keep objects such as your hand away from the antenna and ensure that the antenna on the transmitter has a clear and unobstructed line-of-sight path to the receiver board. Range performance is determined by many interdependent factors. If the range you are able to achieve is significantly less than specified by Linx for the products you are –14 – testing, then there is likely a problem with either the board or the ambient RF environment in which the board is operating. First, check the battery, switch positions, and antenna connection. Next, measure the receiver’s RSSI voltage with the transmitter turned off to determine if ambient interference is present. If this fails to resolve the issue, please contact Linx technical support. Master Development Software The development system is supplied with Windows-based software that facilitates communication with the development boards through either a USB or RS-232 connection. The software allows for configuration of the modules and sends text characters in a chat format. The development system can be used with HyperTerminal to receive and transmit RS-232 data and send files using file transfer protocols such as ZMODEM. HyperTerminal and many other terminal programs assert RTS by default. On the evaluation board, the RTS line is tied to the CMD line on the module. When the CMD line is held low (RTS line is asserted), the module is placed in command mode. In command mode, all UART data sent to the module is interpreted as commands and is NOT sent to the RF engine for transmission. Additionally, if a development board is switched on in the presence of an asserted RTS line, it performs a full hardware and flash reset to the factory defaults. To use the evaluation board with HyperTerminal or other terminal programs, first remove the jumpers from between pins 7 and 8 of JP2, if using the RS-232 interface, or JP3, if using the USB interface. Removing this jumper disconnects the RTS line from the CMD line on the module, allowing normal operation. The development software has three tabs for configuring and using the mdoule: Volatile Registers, Non-Volatile Registers and Wireless Chat. The Volatile Registers and Non-Volatile Registers tabs are used to configure the operation of the module. The Wireless Chat tab is a demonstration using the module. – 15 – The Volatile Registers Tab The Volatile Registers tab tab displays all of the items that can be configured in volatile memory. Values programmed into these registers are lost on power-down, but have an immediate effect on module operation. If the Data Rate register is changed here, then the software needs to be restarted and the new baud rate selected. Please see the 250 Series Transceiver Data Guide for details on the register settings. Figure 16: 250 Series Transceiver Development System Software Volatile Registers Tab –16 – The Non-Volatile Registers Tab The Non-Volatile Registers tab allows the configuration of the non-volatile registers. These are the default values that are loaded when the module powers on and are retained when power is removed from the module. Please see the 250 Series Transceiver Data Guide for details on the register settings. Figure 17: 250 Series Transceiver Development System Software Non-Volatile Registers Tab – 17 – The Wireless Chat Tab The wireless chat tab demonstrates the capability of the 250 Series transceiver to be used as a wireless communications link. Text typed into the lower box is transmitted to a remote module. Text received from another module is displayed in the top box. In this way two development boards can be set up for wireless chat. Figure 18: 250 Series Transceiver Development System Software Wireless Chat Tab The text is prefixed with the Node identifier in the text box at the top. This makes it easy to know who sent the text. Uncheck the Send Node Identifier box to disable this. If the Echo Completed Commands box is checked the middle window displays the commands and text sent to the connected module by the software. The Clear Output Window button at the bottom clears the screens. –18 – Diagnostic Command Modes The Volatile Registers tab has a selection at the bottom to show the Diagnostic Command window. Figure 19: Diagnostic Window Controls on the Volatile Registers Tab Figure 20: 250 Series Transceiver Development System Software Diagnostics Window These commands place the module into special diagnostic modes that can be used to test the module’s performance, or to activate the transmitter for RF testing purposes. Once a module executes a diagnostic command, it should be reset or have the power cycled to return to normal operation. Transmit Diagnostic consists of the controls located in the “Transmit Diagnostic” group. The transmit diagnostic group is broken into two smaller sub-groups. Clicking the “TX 1-Channel Diag” button stops the module from hopping frequencies. The radio buttons on the left allow quick selection of the transmitter’s frequency. Once activated, a “…1010101010101…” bit pattern is transmitted for bit error testing or RF carrier analysis. This single-channel transmit diagnostic mode can be used with the receive diagnostic. In the middle, the light-orange colored box controls the power and modulation characteristics of the transmitter. There are four power settings of increasing intensity: Low, Mid-Low, Mid-High, and High. The “Mod Off” and “Mod On” buttons switch the carrier’s modulation off and on, respectively. – 19 – The right side is used to observe dynamic transmitter characteristics. Dynamic transmitter operation allows the module to hop frequencies as it transmits. The “Hop Set” radio button selects the hop sequence (values are 0-5) to be used when hopping. Dynamic transmitter mode cannot be used to provide a carrier for the Receive Diagnostic. Clicking the “Tx FHSS Diag” button sends the new hopping sequence value to the module and activates the transmitter. The “Start Hop” and “Stop Hop” buttons start and stop the diagnostic hopping, respectively. Receive Diagnostic consists of four radio buttons which allow the selection of frequency, the “Set RX Diag” button which activates the module’s receiver and begins a bit error test, and the result box, which shows the number of bit errors recorded in the last test. The “Set RX Diag” button switches on the receiver using the channel and mode selected in the channel selector and transceiver mode controls. The module stops hopping and stays on a single frequency. It waits for a “10101010...” bit pattern at the RF interface. If one is not received, the module could remain in an infinite loop waiting for this start condition. If this happens, simply cycle the power to return the module to normal operation. If a “…1010101010101…” bit pattern is received, the BER test returns the number and percent of bit errors. This information is displayed in the panel below the “Set RX Diag” button. The Receive Diagnostic mode can be used in conjunction with another module operating in “Tx 1-Channel Diag” mode. Both transmitting and receiving modules must be on the same frequency and have the same baud rate selected for proper operation of the bit error test. –20 – About Antennas The choice of antennas is one of the most critical and often overlooked design considerations. The range, performance, and legality of an RF link are critically dependent upon the type of antenna employed. Linx offers a variety of antenna styles that can be considered for a design. Included with the kit is a Linx CW Series connectorized whip antenna that should be connected prior to using the kit. Despite the fact that the antenna is not centered on the board’s ground plane, it exhibits a VSWR of