Reference firmware for PixArt's PMW3901MB sensor and evaluation board. "Hello World" and "Library" contain the exact same files. Please import just one of the two into your mBed compiler as a new program and not as a library.
Welcome to the code repository for PixArt's PMW3901MB sensor and evaluation board.
For general information about this product, please visit this product's components page here:
https://os.mbed.com/components/PMW3901MB-Far-Field-Optical-Motion-Track/
For guides and tips on how to setup and evaluate the PMW3901MB sensor with the Nordic nRF52-DK microcontroller using this reference code, please visit this guide:
https://os.mbed.com/teams/PixArt/code/3901_referenceFirmware/wiki/Guide-for-nRF52-DK-Platform
For guides and tips on how to setup and evaluate the PMW3901MB sensor with any microcontroller using this reference code, please visit this guide:
https://os.mbed.com/teams/PixArt/code/3901_referenceFirmware/wiki/Guide-for-Any-Platform
commHeaders/SPIcommFunctions.h
- Committer:
- PixArtVY
- Date:
- 2018-03-14
- Revision:
- 0:c00f2464eee3
File content as of revision 0:c00f2464eee3:
//========================================================================= //Communication pinouts for serial COM port, SPI, and interrupts //========================================================================= static Serial pc(USBTX, USBRX); //PC comm static SPI spi(p23, p24, p25); //mosi, miso, sclk static DigitalOut cs(p22); //chip select //========================================================================= //Variables and arrays used for communications and data storage //========================================================================= int8_t deltaX_low, deltaY_low; //Stores the low-bits of movement data. int16_t deltaX_high, deltaY_high; //Stores the high-bits of movement data. int16_t deltaX, deltaY; //Stores the combined value of low and high bits. int16_t totalX, totalY = 0; //Stores the total deltaX and deltaY moved during runtime. //========================================================================= //Functions used to communicate with the sensor and grab/print data //========================================================================= uint8_t readRegister(uint8_t addr); //This function takes an 8-bit address in the form 0x00 and returns an 8-bit value in the form 0x00. void writeRegister(uint8_t addr, uint8_t data); //This function takes an 8-bit address and 8-bit data. Writes the given data to the given address. void initializeSensor(void); //Sets all of the registers needed for initialization and performance optimization. void grabData(void); //Grabs the deltaX and deltaY information from the proper registers and formats it into the proper format. void printData(void); //Prints the data out to a serial terminal. //========================================================================= //Functions definitions //========================================================================= uint8_t readRegister(uint8_t addr) { cs = 0; //Set chip select low/active addr = addr & 0x7F; //Set MSB to 0 to indicate read operation spi.write(addr); //Write the given address wait_us(35); //Add a tiny delay after sending address for some internal cycle timing. uint8_t data_read = spi.write(0x00); //Throw dummy byte after sending address to receieve data cs = 1; //Set chip select back to high/inactive return data_read; //Returns 8-bit data from register } //========================================================================= void writeRegister(uint8_t addr, uint8_t data) { cs = 0; //Set chip select low/active addr = addr | 0x80; //Set MSB to 1 to indicate write operation spi.write(addr); //Write the given address spi.write(data); //Write the given data cs = 1; //Set chip select back to high/inactive //pc.printf("R:%2X, D:%2X\n\r", addr, readRegister(addr)); //Uncomment this line for debugging. Prints every register write operation. } //========================================================================= void initializeSensor(void) { writeRegister(0x7F, 0x00); writeRegister(0x55, 0x01); writeRegister(0x50, 0x07); writeRegister(0x7F, 0x0E); writeRegister(0x43, 0x10); if(readRegister(0x67) & 0x40) writeRegister(0x48, 0x04); else writeRegister(0x48, 0x02); writeRegister(0x7F, 0x00); writeRegister(0x51, 0x7B); writeRegister(0x50, 0x00); writeRegister(0x55, 0x00); writeRegister(0x7F, 0x0E); if(readRegister(0x73) == 0x00) { writeRegister(0x7F, 0x00); writeRegister(0x61, 0xAD); writeRegister(0x51, 0x70); writeRegister(0x7F, 0x0E); if(readRegister(0x70) <= 28) writeRegister(0x70, readRegister(0x70) + 14); else writeRegister(0x70, readRegister(0x70) + 11); writeRegister(0x71, readRegister(0x71) * 45/100); } writeRegister(0x7F, 0x00); writeRegister(0x61, 0xAD); writeRegister(0x7F, 0x03); writeRegister(0x40, 0x00); writeRegister(0x7F, 0x05); writeRegister(0x41, 0xB3); writeRegister(0x43, 0xF1); writeRegister(0x45, 0x14); writeRegister(0x5B, 0x32); writeRegister(0x5F, 0x34); writeRegister(0x7B, 0x08); writeRegister(0x7F, 0x06); writeRegister(0x44, 0x1B); writeRegister(0x40, 0xBF); writeRegister(0x4E, 0x3F); writeRegister(0x7F, 0x06); writeRegister(0x44, 0x1B); writeRegister(0x40, 0xBF); writeRegister(0x4E, 0x3F); writeRegister(0x7F, 0x08); writeRegister(0x65, 0x20); writeRegister(0x6A, 0x18); writeRegister(0x7F, 0x09); writeRegister(0x4F, 0xAF); writeRegister(0x5F, 0x40); writeRegister(0x48, 0x80); writeRegister(0x49, 0x80); writeRegister(0x57, 0x77); writeRegister(0x60, 0x78); writeRegister(0x61, 0x78); writeRegister(0x62, 0x08); writeRegister(0x63, 0x50); writeRegister(0x7F, 0x0A); writeRegister(0x45, 0x60); writeRegister(0x7F, 0x00); writeRegister(0x4D, 0x11); writeRegister(0x55, 0x80); writeRegister(0x74, 0x21); writeRegister(0x75, 0x1F); writeRegister(0x4A, 0x78); writeRegister(0x4B, 0x78); writeRegister(0x44, 0x08); writeRegister(0x45, 0x50); writeRegister(0x64, 0xFF); writeRegister(0x65, 0x1F); writeRegister(0x7F, 0x14); writeRegister(0x65, 0x67); writeRegister(0x66, 0x08); writeRegister(0x63, 0x70); writeRegister(0x7F, 0x15); writeRegister(0x48, 0x48); writeRegister(0x7F, 0x07); writeRegister(0x41, 0x0D); writeRegister(0x43, 0x14); writeRegister(0x4B, 0x0E); writeRegister(0x45, 0x0F); writeRegister(0x44, 0x42); writeRegister(0x4C, 0x80); writeRegister(0x7F, 0x10); writeRegister(0x5B, 0x02); writeRegister(0x7F, 0x07); writeRegister(0x40, 0x41); writeRegister(0x70, 0x00); wait_ms(10); writeRegister(0x32, 0x44); writeRegister(0x7F, 0x07); writeRegister(0x40, 0x40); writeRegister(0x7F, 0x06); writeRegister(0x62, 0xF0); writeRegister(0x63, 0x00); writeRegister(0x7F, 0x0D); writeRegister(0x48, 0xC0); writeRegister(0x6F, 0xD5); writeRegister(0x7F, 0x00); writeRegister(0x5B, 0xA0); writeRegister(0x4E, 0xA8); writeRegister(0x5A, 0x50); writeRegister(0x40, 0x80); } //========================================================================= void grabData(void) { deltaX_low = readRegister(0x03); //Grabs data from the proper registers. deltaX_high = (readRegister(0x04)<<8) & 0xFF00; //Grabs data and shifts it to make space to be combined with lower bits. deltaY_low = readRegister(0x05); deltaY_high = (readRegister(0x06)<<8) & 0xFF00; deltaX = deltaX_high | deltaX_low; //Combines the low and high bits. deltaY = deltaY_high | deltaY_low; } //========================================================================= void printData(void) { if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data. { totalX += deltaX; totalY += deltaY; pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY); //Prints each individual count of deltaX and deltaY. pc.printf("X-axis Counts: %d\t\tY-axis Counts: %d\n\r", totalX, totalY); //Prints the total movement made during runtime. } deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten. deltaY = 0; }