PixArt / Mbed OS 3901_referenceFirmware

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@1:10365086d44e, 2018-07-18 (annotated)

Committer:
PixArtVY
Date:
Wed Jul 18 18:37:21 2018 +0000
Revision:
1:10365086d44e
Parent:
0:c00f2464eee3 
Added Apache License notice.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
PixArtVY 0:c00f2464eee3 1 //=========================================================================
PixArtVY 0:c00f2464eee3 2 //Communication pinouts for serial COM port, SPI, and interrupts
PixArtVY 0:c00f2464eee3 3 //=========================================================================
PixArtVY 0:c00f2464eee3 4 static Serial pc(USBTX, USBRX); //PC comm
PixArtVY 0:c00f2464eee3 5 static SPI spi(p23, p24, p25); //mosi, miso, sclk
PixArtVY 0:c00f2464eee3 6 static DigitalOut cs(p22); //chip select
PixArtVY 0:c00f2464eee3 7
PixArtVY 0:c00f2464eee3 8
PixArtVY 0:c00f2464eee3 9 //=========================================================================
PixArtVY 0:c00f2464eee3 10 //Variables and arrays used for communications and data storage
PixArtVY 0:c00f2464eee3 11 //=========================================================================
PixArtVY 0:c00f2464eee3 12 int8_t deltaX_low, deltaY_low; //Stores the low-bits of movement data.
PixArtVY 0:c00f2464eee3 13 int16_t deltaX_high, deltaY_high; //Stores the high-bits of movement data.
PixArtVY 0:c00f2464eee3 14 int16_t deltaX, deltaY; //Stores the combined value of low and high bits.
PixArtVY 0:c00f2464eee3 15 int16_t totalX, totalY = 0; //Stores the total deltaX and deltaY moved during runtime.
PixArtVY 0:c00f2464eee3 16
PixArtVY 0:c00f2464eee3 17
PixArtVY 0:c00f2464eee3 18 //=========================================================================
PixArtVY 0:c00f2464eee3 19 //Functions used to communicate with the sensor and grab/print data
PixArtVY 0:c00f2464eee3 20 //=========================================================================
PixArtVY 0:c00f2464eee3 21 uint8_t readRegister(uint8_t addr);
PixArtVY 0:c00f2464eee3 22 //This function takes an 8-bit address in the form 0x00 and returns an 8-bit value in the form 0x00.
PixArtVY 0:c00f2464eee3 23
PixArtVY 0:c00f2464eee3 24 void writeRegister(uint8_t addr, uint8_t data);
PixArtVY 0:c00f2464eee3 25 //This function takes an 8-bit address and 8-bit data. Writes the given data to the given address.
PixArtVY 0:c00f2464eee3 26
PixArtVY 0:c00f2464eee3 27 void initializeSensor(void);
PixArtVY 0:c00f2464eee3 28 //Sets all of the registers needed for initialization and performance optimization.
PixArtVY 0:c00f2464eee3 29
PixArtVY 0:c00f2464eee3 30 void grabData(void);
PixArtVY 0:c00f2464eee3 31 //Grabs the deltaX and deltaY information from the proper registers and formats it into the proper format.
PixArtVY 0:c00f2464eee3 32
PixArtVY 0:c00f2464eee3 33 void printData(void);
PixArtVY 0:c00f2464eee3 34 //Prints the data out to a serial terminal.
PixArtVY 0:c00f2464eee3 35
PixArtVY 0:c00f2464eee3 36
PixArtVY 0:c00f2464eee3 37
PixArtVY 0:c00f2464eee3 38
PixArtVY 0:c00f2464eee3 39
PixArtVY 0:c00f2464eee3 40 //=========================================================================
PixArtVY 0:c00f2464eee3 41 //Functions definitions
PixArtVY 0:c00f2464eee3 42 //=========================================================================
PixArtVY 0:c00f2464eee3 43 uint8_t readRegister(uint8_t addr)
PixArtVY 0:c00f2464eee3 44 {
PixArtVY 0:c00f2464eee3 45 cs = 0; //Set chip select low/active
PixArtVY 0:c00f2464eee3 46 addr = addr & 0x7F; //Set MSB to 0 to indicate read operation
PixArtVY 0:c00f2464eee3 47 spi.write(addr); //Write the given address
PixArtVY 0:c00f2464eee3 48 wait_us(35); //Add a tiny delay after sending address for some internal cycle timing.
PixArtVY 0:c00f2464eee3 49 uint8_t data_read = spi.write(0x00); //Throw dummy byte after sending address to receieve data
PixArtVY 0:c00f2464eee3 50 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:c00f2464eee3 51 return data_read; //Returns 8-bit data from register
PixArtVY 0:c00f2464eee3 52 }
PixArtVY 0:c00f2464eee3 53
PixArtVY 0:c00f2464eee3 54
PixArtVY 0:c00f2464eee3 55 //=========================================================================
PixArtVY 0:c00f2464eee3 56 void writeRegister(uint8_t addr, uint8_t data)
PixArtVY 0:c00f2464eee3 57 {
PixArtVY 0:c00f2464eee3 58 cs = 0; //Set chip select low/active
PixArtVY 0:c00f2464eee3 59 addr = addr | 0x80; //Set MSB to 1 to indicate write operation
PixArtVY 0:c00f2464eee3 60 spi.write(addr); //Write the given address
PixArtVY 0:c00f2464eee3 61 spi.write(data); //Write the given data
PixArtVY 0:c00f2464eee3 62 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:c00f2464eee3 63
PixArtVY 0:c00f2464eee3 64 //pc.printf("R:%2X, D:%2X\n\r", addr, readRegister(addr));
PixArtVY 0:c00f2464eee3 65 //Uncomment this line for debugging. Prints every register write operation.
PixArtVY 0:c00f2464eee3 66 }
PixArtVY 0:c00f2464eee3 67
PixArtVY 0:c00f2464eee3 68
PixArtVY 0:c00f2464eee3 69 //=========================================================================
PixArtVY 0:c00f2464eee3 70 void initializeSensor(void)
PixArtVY 0:c00f2464eee3 71 {
PixArtVY 0:c00f2464eee3 72 writeRegister(0x7F, 0x00);
PixArtVY 0:c00f2464eee3 73 writeRegister(0x55, 0x01);
PixArtVY 0:c00f2464eee3 74 writeRegister(0x50, 0x07);
PixArtVY 0:c00f2464eee3 75 writeRegister(0x7F, 0x0E);
PixArtVY 0:c00f2464eee3 76 writeRegister(0x43, 0x10);
PixArtVY 0:c00f2464eee3 77
PixArtVY 0:c00f2464eee3 78 if(readRegister(0x67) & 0x40)
PixArtVY 0:c00f2464eee3 79 writeRegister(0x48, 0x04);
PixArtVY 0:c00f2464eee3 80
PixArtVY 0:c00f2464eee3 81 else
PixArtVY 0:c00f2464eee3 82 writeRegister(0x48, 0x02);
PixArtVY 0:c00f2464eee3 83
PixArtVY 0:c00f2464eee3 84 writeRegister(0x7F, 0x00);
PixArtVY 0:c00f2464eee3 85 writeRegister(0x51, 0x7B);
PixArtVY 0:c00f2464eee3 86 writeRegister(0x50, 0x00);
PixArtVY 0:c00f2464eee3 87 writeRegister(0x55, 0x00);
PixArtVY 0:c00f2464eee3 88 writeRegister(0x7F, 0x0E);
PixArtVY 0:c00f2464eee3 89
PixArtVY 0:c00f2464eee3 90 if(readRegister(0x73) == 0x00)
PixArtVY 0:c00f2464eee3 91 {
PixArtVY 0:c00f2464eee3 92 writeRegister(0x7F, 0x00);
PixArtVY 0:c00f2464eee3 93 writeRegister(0x61, 0xAD);
PixArtVY 0:c00f2464eee3 94 writeRegister(0x51, 0x70);
PixArtVY 0:c00f2464eee3 95 writeRegister(0x7F, 0x0E);
PixArtVY 0:c00f2464eee3 96
PixArtVY 0:c00f2464eee3 97 if(readRegister(0x70) <= 28)
PixArtVY 0:c00f2464eee3 98 writeRegister(0x70, readRegister(0x70) + 14);
PixArtVY 0:c00f2464eee3 99
PixArtVY 0:c00f2464eee3 100 else
PixArtVY 0:c00f2464eee3 101 writeRegister(0x70, readRegister(0x70) + 11);
PixArtVY 0:c00f2464eee3 102
PixArtVY 0:c00f2464eee3 103 writeRegister(0x71, readRegister(0x71) * 45/100);
PixArtVY 0:c00f2464eee3 104 }
PixArtVY 0:c00f2464eee3 105
PixArtVY 0:c00f2464eee3 106 writeRegister(0x7F, 0x00);
PixArtVY 0:c00f2464eee3 107 writeRegister(0x61, 0xAD);
PixArtVY 0:c00f2464eee3 108 writeRegister(0x7F, 0x03);
PixArtVY 0:c00f2464eee3 109 writeRegister(0x40, 0x00);
PixArtVY 0:c00f2464eee3 110 writeRegister(0x7F, 0x05);
PixArtVY 0:c00f2464eee3 111 writeRegister(0x41, 0xB3);
PixArtVY 0:c00f2464eee3 112 writeRegister(0x43, 0xF1);
PixArtVY 0:c00f2464eee3 113 writeRegister(0x45, 0x14);
PixArtVY 0:c00f2464eee3 114 writeRegister(0x5B, 0x32);
PixArtVY 0:c00f2464eee3 115 writeRegister(0x5F, 0x34);
PixArtVY 0:c00f2464eee3 116 writeRegister(0x7B, 0x08);
PixArtVY 0:c00f2464eee3 117 writeRegister(0x7F, 0x06);
PixArtVY 0:c00f2464eee3 118 writeRegister(0x44, 0x1B);
PixArtVY 0:c00f2464eee3 119 writeRegister(0x40, 0xBF);
PixArtVY 0:c00f2464eee3 120 writeRegister(0x4E, 0x3F);
PixArtVY 0:c00f2464eee3 121 writeRegister(0x7F, 0x06);
PixArtVY 0:c00f2464eee3 122 writeRegister(0x44, 0x1B);
PixArtVY 0:c00f2464eee3 123 writeRegister(0x40, 0xBF);
PixArtVY 0:c00f2464eee3 124 writeRegister(0x4E, 0x3F);
PixArtVY 0:c00f2464eee3 125 writeRegister(0x7F, 0x08);
PixArtVY 0:c00f2464eee3 126 writeRegister(0x65, 0x20);
PixArtVY 0:c00f2464eee3 127 writeRegister(0x6A, 0x18);
PixArtVY 0:c00f2464eee3 128 writeRegister(0x7F, 0x09);
PixArtVY 0:c00f2464eee3 129 writeRegister(0x4F, 0xAF);
PixArtVY 0:c00f2464eee3 130 writeRegister(0x5F, 0x40);
PixArtVY 0:c00f2464eee3 131 writeRegister(0x48, 0x80);
PixArtVY 0:c00f2464eee3 132 writeRegister(0x49, 0x80);
PixArtVY 0:c00f2464eee3 133 writeRegister(0x57, 0x77);
PixArtVY 0:c00f2464eee3 134 writeRegister(0x60, 0x78);
PixArtVY 0:c00f2464eee3 135 writeRegister(0x61, 0x78);
PixArtVY 0:c00f2464eee3 136 writeRegister(0x62, 0x08);
PixArtVY 0:c00f2464eee3 137 writeRegister(0x63, 0x50);
PixArtVY 0:c00f2464eee3 138 writeRegister(0x7F, 0x0A);
PixArtVY 0:c00f2464eee3 139 writeRegister(0x45, 0x60);
PixArtVY 0:c00f2464eee3 140 writeRegister(0x7F, 0x00);
PixArtVY 0:c00f2464eee3 141 writeRegister(0x4D, 0x11);
PixArtVY 0:c00f2464eee3 142 writeRegister(0x55, 0x80);
PixArtVY 0:c00f2464eee3 143 writeRegister(0x74, 0x21);
PixArtVY 0:c00f2464eee3 144 writeRegister(0x75, 0x1F);
PixArtVY 0:c00f2464eee3 145 writeRegister(0x4A, 0x78);
PixArtVY 0:c00f2464eee3 146 writeRegister(0x4B, 0x78);
PixArtVY 0:c00f2464eee3 147 writeRegister(0x44, 0x08);
PixArtVY 0:c00f2464eee3 148 writeRegister(0x45, 0x50);
PixArtVY 0:c00f2464eee3 149 writeRegister(0x64, 0xFF);
PixArtVY 0:c00f2464eee3 150 writeRegister(0x65, 0x1F);
PixArtVY 0:c00f2464eee3 151 writeRegister(0x7F, 0x14);
PixArtVY 0:c00f2464eee3 152 writeRegister(0x65, 0x67);
PixArtVY 0:c00f2464eee3 153 writeRegister(0x66, 0x08);
PixArtVY 0:c00f2464eee3 154 writeRegister(0x63, 0x70);
PixArtVY 0:c00f2464eee3 155 writeRegister(0x7F, 0x15);
PixArtVY 0:c00f2464eee3 156 writeRegister(0x48, 0x48);
PixArtVY 0:c00f2464eee3 157 writeRegister(0x7F, 0x07);
PixArtVY 0:c00f2464eee3 158 writeRegister(0x41, 0x0D);
PixArtVY 0:c00f2464eee3 159 writeRegister(0x43, 0x14);
PixArtVY 0:c00f2464eee3 160 writeRegister(0x4B, 0x0E);
PixArtVY 0:c00f2464eee3 161 writeRegister(0x45, 0x0F);
PixArtVY 0:c00f2464eee3 162 writeRegister(0x44, 0x42);
PixArtVY 0:c00f2464eee3 163 writeRegister(0x4C, 0x80);
PixArtVY 0:c00f2464eee3 164 writeRegister(0x7F, 0x10);
PixArtVY 0:c00f2464eee3 165 writeRegister(0x5B, 0x02);
PixArtVY 0:c00f2464eee3 166 writeRegister(0x7F, 0x07);
PixArtVY 0:c00f2464eee3 167 writeRegister(0x40, 0x41);
PixArtVY 0:c00f2464eee3 168 writeRegister(0x70, 0x00);
PixArtVY 0:c00f2464eee3 169
PixArtVY 0:c00f2464eee3 170 wait_ms(10);
PixArtVY 0:c00f2464eee3 171
PixArtVY 0:c00f2464eee3 172 writeRegister(0x32, 0x44);
PixArtVY 0:c00f2464eee3 173 writeRegister(0x7F, 0x07);
PixArtVY 0:c00f2464eee3 174 writeRegister(0x40, 0x40);
PixArtVY 0:c00f2464eee3 175 writeRegister(0x7F, 0x06);
PixArtVY 0:c00f2464eee3 176 writeRegister(0x62, 0xF0);
PixArtVY 0:c00f2464eee3 177 writeRegister(0x63, 0x00);
PixArtVY 0:c00f2464eee3 178 writeRegister(0x7F, 0x0D);
PixArtVY 0:c00f2464eee3 179 writeRegister(0x48, 0xC0);
PixArtVY 0:c00f2464eee3 180 writeRegister(0x6F, 0xD5);
PixArtVY 0:c00f2464eee3 181 writeRegister(0x7F, 0x00);
PixArtVY 0:c00f2464eee3 182 writeRegister(0x5B, 0xA0);
PixArtVY 0:c00f2464eee3 183 writeRegister(0x4E, 0xA8);
PixArtVY 0:c00f2464eee3 184 writeRegister(0x5A, 0x50);
PixArtVY 0:c00f2464eee3 185 writeRegister(0x40, 0x80);
PixArtVY 0:c00f2464eee3 186 }
PixArtVY 0:c00f2464eee3 187
PixArtVY 0:c00f2464eee3 188
PixArtVY 0:c00f2464eee3 189 //=========================================================================
PixArtVY 0:c00f2464eee3 190 void grabData(void)
PixArtVY 0:c00f2464eee3 191 {
PixArtVY 0:c00f2464eee3 192 deltaX_low = readRegister(0x03); //Grabs data from the proper registers.
PixArtVY 0:c00f2464eee3 193 deltaX_high = (readRegister(0x04)<<8) & 0xFF00; //Grabs data and shifts it to make space to be combined with lower bits.
PixArtVY 0:c00f2464eee3 194 deltaY_low = readRegister(0x05);
PixArtVY 0:c00f2464eee3 195 deltaY_high = (readRegister(0x06)<<8) & 0xFF00;
PixArtVY 0:c00f2464eee3 196
PixArtVY 0:c00f2464eee3 197 deltaX = deltaX_high | deltaX_low; //Combines the low and high bits.
PixArtVY 0:c00f2464eee3 198 deltaY = deltaY_high | deltaY_low;
PixArtVY 0:c00f2464eee3 199 }
PixArtVY 0:c00f2464eee3 200
PixArtVY 0:c00f2464eee3 201
PixArtVY 0:c00f2464eee3 202 //=========================================================================
PixArtVY 0:c00f2464eee3 203 void printData(void)
PixArtVY 0:c00f2464eee3 204 {
PixArtVY 0:c00f2464eee3 205 if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data.
PixArtVY 0:c00f2464eee3 206 {
PixArtVY 0:c00f2464eee3 207 totalX += deltaX;
PixArtVY 0:c00f2464eee3 208 totalY += deltaY;
PixArtVY 0:c00f2464eee3 209
PixArtVY 0:c00f2464eee3 210 pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY); //Prints each individual count of deltaX and deltaY.
PixArtVY 0:c00f2464eee3 211 pc.printf("X-axis Counts: %d\t\tY-axis Counts: %d\n\r", totalX, totalY); //Prints the total movement made during runtime.
PixArtVY 0:c00f2464eee3 212 }
PixArtVY 0:c00f2464eee3 213
PixArtVY 0:c00f2464eee3 214 deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
PixArtVY 0:c00f2464eee3 215 deltaY = 0;
PixArtVY 0:c00f2464eee3 216 }