EV3672B

The MC3672 Evaluation Board Quick Start Guide and Demo GENERAL DESCRIPTION MC3672 FEATURES The MC3672 is an ultra-low power, lownoise, integrated digital output 3-axis accelerometer with a feature set optimized for wearables and consumer product motion sensing. Applications include wearable consumer products, IoT devices, user interface control, gaming motion input, electronic compass tilt compensation for cell phones, game controllers, remote controls and portable media products. Range, Sampling & Power The EV3672A/B is a prebuilt circuit board with MC3672 WLCSP 3-axes sensor. The MC3672 has internal sample rate from 14 to 1300 samples / second and measures acceleration with a wide usage range, from +/-2g up to +/-16g, and 6-bit to 14-bit high precision ADC output, which is easy to fit on top of the microcontroller, such as an Arduino. The accelerometer communicates via I2C/SPI and gives out motion detection or sample acquisition conditions to trigger an interrupt toward an MCU.         Simple System Integration The sensor data is easily readable by connecting DVDD to 3.3V, GND to ground, and SCL/SDA pins to your Arduino I2C clock and data pin respectively. Download the MC3672 library from MEMSIC onto the board, run the example sketch, and then sensor data shortly comes out in raw data count and SI unit accelerometer measurements. An easy-to-use demonstration on EV3672A/B using the Arduino platform is included in this document. MEMSIC EV3672A+B APS-045-0017 v1.6 ±2, 4, 8, 12 or 16g ranges 8, 10 or 12-bit resolution with FIFO o 14-bit single samples Sample rate 14 - 1300 samples/sec Sample trigger via internal oscillator, clock pin or software command Sniff and Wake modes 0.4 μA Sniff current @ 6Hz Separate or combined sniff/wake Ultra-Low Power with 32 sample FIFO o 0.9 μA typical current @ 25Hz o 1.6 μA typical current @ 50Hz o 2.8 μA typical current @ 100Hz o 36 μA typical current @ 1300Hz Page 1 of 19      I2C interface, up to 1 MHz SPI Interface, up to 8 MHz 1.29 × 1.09 × 0.742 mm 8-pin WLCSP package Single-chip 3D silicon MEMS Low noise to 2.3mg RMS Formal release date: 2020/08/12 TABLE OF CONTENTS 1 General Operation ........................................................................................................... 3 1.1 Pinouts ................................................................................................................................. 3 1.2 Power Pins ........................................................................................................................... 3 1.3 I2C Pins ............................................................................................................................... 4 1.4 SPI Pins ............................................................................................................................... 5 1.5 Interrupt Pins........................................................................................................................ 5 2 Assembly and Test .......................................................................................................... 6 2.1 I2C Interface ........................................................................................................................ 6 2.2 SPI Interface ........................................................................................................................ 7 3 Demo ............................................................................................................................... 8 3.1 GET the Driver from MEMSIC .............................................................................................. 8 3.2 Load the Demo .................................................................................................................... 8 4 Library Reference .......................................................................................................... 11 4.1 Create MEMSIC_MC36XX Object ...................................................................................... 11 4.2 Initialize and Configure Sensor........................................................................................... 11 4.3 Set Range .......................................................................................................................... 11 4.4 Read Range ....................................................................................................................... 11 4.5 Set Resolution .................................................................................................................... 11 4.6 Read Resolution................................................................................................................. 12 4.7 Set CWake Sampling Rate ................................................................................................. 12 4.8 Read CWake Sampling Rate.............................................................................................. 12 4.9 Set Sniff Sampling Rate ..................................................................................................... 12 4.10 Read Sniff Sampling Rate .................................................................................................. 12 4.11 Config Sniff Mode............................................................................................................... 12 4.12 Config Interrupt Mode ........................................................................................................ 13 4.13 Read Raw Count Data ....................................................................................................... 13 5 Schematics .................................................................................................................... 14 6 Bill of Materials .............................................................................................................. 16 7 Fabrication Print............................................................................................................. 17 8 Note ............................................................................................................................... 18 9 Revision History ............................................................................................................. 19 MEMSIC EV3672A+B APS-045-0017 v1.6 Page 2 of 19 Formal release date: 2020/08/12 1 GENERAL OPERATION 1.1 PINOUTS 1.2 POWER PINS      DVDD – 3.3V Power Supply Input GND – Ground Pin for Power and Logic R7: The current drawn the sensor can be measured by putting an ammeter in place of R7. In the following demonstration, an Arduino DUE is used to illustrate on how to test the evaluation board with a microcontroller. Please be advised that if an Arduino UNO is used instead, hardware modification on Arduino UNO MUST be made for it to output at 3.3V. (WARNING: attempting to power the part at 5V is likely to damage it.) By default, Arduino UNO operates at 5V, which is higher than the maximum voltage rating for the evaluation board. Please refer to an excellent tutorial on modifying Arduino UNO to output at 3.3V: https://learn.adafruit.com/arduino-tips-tricks-and-techniques/3-3v-conversion MEMSIC EV3672A+B APS-045-0017 v1.6 Page 3 of 19 Formal release date: 2020/08/12 1.3 I2C PINS   Connect the SCL (I2C clock pin) to your microcontroller’s I2C clock line. Connect the SDA (I2C data pin) to your microcontroller’s I2C data line. R4, R5: If using I2C and I2C pull-up resistors are needed for your application then install~4.7KΩ resistors into R4 (SCL clock pin) and R5 (SDA data pin) which are not installed by factory default. In addition, besides soldering resisters on R4/R5, you can add axial lead 4.7K ohm resistors to the SDA and SCL pin respectively. It will work the same either way. NOTE: DO NOT install more than one setup pull-up resistors per I2C bus. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 4 of 19 Formal release date: 2020/08/12 1.4 SPI PINS With an SPI connection, there is always one master device (usually a microcontroller) which controls the peripheral devices. Typically, there are four wires commonly connected to all the devices: Connect the SCS (Slave Chip Select) to the pin on the device that the master can use to enable and disable SPI cycles. Connect the SCL (Serial Clock) to the pin where the clock pulses synchronize data transmission generated by the master Connect SDO to the pin where the Slave sends data to the master (Master Input, Slave Output). Connect SDA to the pin where the Master sends data to the peripherals (Master Output, Slave Input). 1.5 INTERRUPT PINS INT - HW interrupt signal pin. This pin will be triggered by the device when data is ready to read, or a motion event is detected by the accelerometer. (Not currently supported in the library for the interrupt pin, so please check the datasheet for the I2C commands and related registers). R6: If using the sensor interrupt signal as open-drain, then install pull-up resistor ~4.7KΩ into R6 (not installed by default). MEMSIC EV3672A+B APS-045-0017 v1.6 Page 5 of 19 Formal release date: 2020/08/12 2 ASSEMBLY AND TEST Please note that the SPI and I2C interfaces cannot both be active at the same time as the clock (SCK) and data (SDA) are shared between the two protocols. 2.1 I2C INTERFACE The EV3672A/B evaluation board can be easily wired to any microcontroller. This example shows a typical Arduino DUE platform. For other microcontrollers, be sure it has I2C with repeated-start support, then port the code. Please refer to the illustration below to connect the related pins.     Connect DVDD to the power supply, 3.3V. (WARNING: attempting to power the part at a voltage exceeds the maximum rating of 3.6V is likely to damage it.) Connect GND to common power/data ground. Connect the SCL pin to the I2C clock SCL pin on your Arduino. Connect the SDA pin to the I2C data SDA pin on your Arduino. The MC3672 has a default I2C address of 0x4C and it can be changed to 0x6C by tying the SDO pin to VDD. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 6 of 19 Formal release date: 2020/08/12 2.2 SPI INTERFACE The EV3672A/B evaluation board can be easily wired to any microcontroller. This example shows a typical Arduino DUE platform. Please refer to the illustration below for connecting the related pins and then port the code to get the raw X, Y, Z sensor data.       Connect DVDD to the power supply, 3.3V. (WARNING: attempting to power the part at a voltage exceeds the maximum rating of 3.6V is likely to damage it.) Connect GND to common power/data ground. Connect SCL to ICSP-3 as Serial Clock. Connect SDO to ICSP-1 as Master Input, Slave Output. Connect SDA to ICSP-4 as Master Output, Slave Input. Connect SCS to digital I/O pin 10 as Slave Chip Select. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 7 of 19 Formal release date: 2020/08/12 3 DEMO 3.1 GET THE DRIVER FROM MEMSIC To begin reading sensor data, you will need to get the MC3672 Library from MEMSIC. Rename the uncompressed folder Accelerometer_MC36XX and check that the Accelerometer_MC36XX folder consisting of MC36XX.cpp and MC36XX.h If you need the sensor running on SPI, please configure the bus as SPI in the MC36XX.h shown as below. Otherwise, the default is I2C bus. //#define MC36XX_CFG_BUS_I2C #define MC36XX_CFG_BUS_SPI SPI could support 8MHz speed if high speed mode is enabled as below. #define SPI_HS Place the Accelerometer_MC36XX library folder to your Arduino_sketch_folder/libraries/ folder. You may need to create the library subfolder if it is your first library files. Then just restart the IDE. An excellent tutorial on Arduino library installation is located at: http://learn.adafruit.com/adafruit-all-about-arduino-libraries-install-use 3.2 LOAD THE DEMO Open File->Examples->MC36XX-> MC36XX_demo and upload to your Arduino while it is wired to the sensor. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 8 of 19 Formal release date: 2020/08/12 Now open the serial terminal window at 115,200 baud rate speed to begin the test. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 9 of 19 Formal release date: 2020/08/12 You will see the output from the serial terminal showing the current range scale and resolution of the sensor in the first three lines followed by two lines of output sensor data at some output data rate which depict “raw count" data for line 1: X: 18 Y: 24 Z: 1015 with 8G range, 14bit ADC resolution. Line 2 indicates the SI units for measuring acceleration as X: 0.17 m/s^2 Y: 0.23 m/s^2 Z: 9.72 m/s^2. This demo also includes the example for FIFO and Sniff interrupt mode. Those could be enabled by modify the definition below. These two examples must be run separately. #define ENABLE_FIFO_WAKEUP 1 #define ENABLE_SNIFF_SHAKE_WAKEUP 0 Default input pin for interrupt is pin 8 and default FIFO threshold is 3 samples. FIFO size could be set to maximum 32 samples or just enable FIFO to FIFO_FULL mode. #define INTERRUPT_PIN 8 #define FIFO_SIZE 3 MEMSIC EV3672A+B APS-045-0017 v1.6 Page 10 of 19 Formal release date: 2020/08/12 4 LIBRARY REFERENCE 4.1 CREATE MEMSIC_MC36XX OBJECT You can create the MEMSIC_MC36XX object with: MC36XX MC36XX_acc = MC36XX(); 4.2 INITIALIZE AND CONFIGURE SENSOR Initialize and configure the sensor with: MC36XX_acc.start(); Wake up sensor with your own configuration, it will follow the factory default setting: MC36XX_acc.wake(); Stop sensor to change setting: MC36XX_acc.stop(); Set sensor as sniff mode: MC36XX_acc.sniff (); 4.3 SET RANGE Set the accelerometer max range to ±2g, ±4g, ±8g or ±16g with: MC36XX_acc.SetRangeCtrl(MC36XX_RANGE_8G); 4.4 READ RANGE Read the current range with: MC36XX_acc.GetRangeCtrl(); It returns: 0 for ±2g, | 1 for ±4g, | 2 for ±8g | 3 for ±16g. 4.5 SET RESOLUTION Set the accelerometer resolution to 6, 7, 8, 10, 12 or 14 bit. MC36XX_acc.SetResolutionCtrl(MC36XX_RESOLUTION_14BIT); When the FIFO is enabled, the output of the FIFO is mapped to registers 0x02 to 0x07, and the data has a maximum resolution of 12-bits. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 11 of 19 Formal release date: 2020/08/12 4.6 READ RESOLUTION Read the current resolution with: MC36XX_acc.GetResolutionCtrl(); It returns: 0 for 6-bit | 1 for 7-bit | 2 for 8-bit | 3 for 10-bit | 4 for 12-bit | 5 for 14-bit. 4.7 SET CWAKE SAMPLING RATE Set the accelerometer CWake mode sampling rate with: MC36XX_acc.SetCWakeSampleRate (MC36XX_CWAKE_SR_DEFAULT_54Hz); 4.8 READ CWAKE SAMPLING RATE Read the current CWake sampling rate with: MC36XX_acc.GetCWakeSampleRate (); It returns sampling rate from 14 ~ 600 Hz. 4.9 SET SNIFF SAMPLING RATE Set the accelerometer sniff mode sampling rate with: MC36XX_acc.SetSniffSampleRate (MC36XX_SNIFF_SR_DEFAULT_7Hz); 4.10 READ SNIFF SAMPLING RATE Read the current sniff sampling rate with: MC36XX_acc.GetSniffSampleRate (); This returns sampling rate from 0.4 ~ 600 Hz. 4.11 CONFIG SNIFF MODE Set the threshold values used by the SNIFF logic for activity detection: MC36XX_acc.SetSniffThreshold (MC36XX_AXIS_X,5); All three axes could be configured separately with different threshold value. Set the threshold values used by the SNIFF logic for activity detection: MC36XX_acc.SetSniffDetectCount (MC36XX_AXIS_X,3); For each axis, a delta count is generated and compared to the threshold. When the delta count is greater than the threshold, a SNIFF wakeup event occurs. There is a unique MEMSIC EV3672A+B APS-045-0017 v1.6 Page 12 of 19 Formal release date: 2020/08/12 sniff threshold for each axis, and an optional “false detection count” which requires multiple sniff detection events to occur before a wakeup condition is declared. Configure sniff and/or mode with: MC36XX_acc.SetSniffAndOrN(MC36XX_ANDORN_OR); The SNIFF block supports the logical AND or OR of the X/Y/Z SNIFF wakeup flags when generating a SNIFF wakeup interrupt. Configure sniff delta mode with: MC36XX_acc.SetSniffDeltaMode(MC36XX_DELTA_MODE_C2P); C2P mode: The current sample and the immediate previous sample are subtracted generate a delta C2B mode: The current sample and the first sample captured when entering SNIFF mode are subtracted to generate a delta. 4.12 CONFIG INTERRUPT MODE Configure the interrupt mode with: MC36XX_acc.SetINTCtrl(0,0,0,0,1); MC36XX have 5 interrupt modes – FIFO_THR | FIFO FULL | FIFO EMPTY | ACQ | WAKE. These modes can only be enabled separately. 4.13 READ RAW COUNT DATA Read the raw count data and SI unit measurement with: MC36XX_acc.readRawAccel(); MEMSIC EV3672A+B APS-045-0017 v1.6 Page 13 of 19 Formal release date: 2020/08/12 5 SCHEMATICS Above is a schematic on EV3672A/B. This is the factory preset when receiving the part. For other options, please refer to the following table: Interface (EV3672A) R1 R2 R3 SPI (Factory Default) 4.7KΩ DNI 4.7KΩ SPI or I2C 0x4C 100KΩ DNI1 10KΩ SPI or I2C 0x6C 100KΩ 10KΩ DNI R1 R2 R3 SPI or I2C 0x4C (Factory Default) 100KΩ DNI 10KΩ SPI or I2C 0x6C 100KΩ 10KΩ DNI Interface (EV3672B) 1 DNI: Do Not Install MEMSIC EV3672A+B APS-045-0017 v1.6 Page 14 of 19 Formal release date: 2020/08/12 The difference between EV3672A and EV3672B is the resistor values for R1 and R2. EV3672A could be worked on I2C interface by changing R1 value to 100KΩ and R3 value to 10KΩ (for 0x4C I2C address). EV3672B could be worked on I2C interface (with address 0x4C) without any reworking. Configure the bus in the MC36XX Driver accordingly when changing from SPI to I2C interface, and vice versa (please refer to Section 3.1). R4, R5: Install ~4.7KΩ (if no other pull-up installed) as the pull-up for I2C interface. NOTE: It is recommended not to install more than one pull-up per I2C bus. R6: Install ~4.7KΩ pull-up resistor if sensor interrupt pin is set to open-drain. (DNI by default) R7: The driving current of sensor can be measured by putting an ammeter in place of R7. The physical location of the resistor is in the diagram in Section 1.3. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 15 of 19 Formal release date: 2020/08/12 6 BILL OF MATERIALS MEMSIC EV3672A+B APS-045-0017 v1.6 Page 16 of 19 Formal release date: 2020/08/12 7 FABRICATION PRINT NOTE: All dimensions are in millimeters. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 17 of 19 Formal release date: 2020/08/12 8 NOTE All the mCube logo in the document will be replaced later by MEMSIC logo. MEMSIC EV3672A+B APS-045-0017 v1.6 Page 18 of 19 Formal release date: 2020/08/12 9 REVISION HISTORY Date 2016-12 2017-02 2018-05 Revision APS-045-0017v1.0 APS-045-0017v1.1 APS-045-0017v1.2 2018-11 APS-045-0017v1.3 2020-02 APS-045-0017v1.4 2020-03 2020-08-12 APS-045-0017v1.5 APS-045-0017v1.6 MEMSIC EV3672A+B APS-045-0017 v1.6 Description First release. Added SPI mode interface. Added example codes for high speed SPI mode, FIFO mode, and Sniff mode. Added revised schematics with hardware settings for I2C and SPI interface and BOM list. Revised schematics and BOM Added warning in section 1.2. Changed illustration to Arduino DUE. Revised section 3 & 4 to illustrate demo program. Added description for A/B versions in Section 5. Change to MEMSIC format based on the License Agreement with mCube Page 19 of 19 Formal release date: 2020/08/12