PixArt / Mbed OS 9125_referenceCode

Reference firmware for PixArt's PAT9125EL 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 PAT9125EL sensor and evaluation board.

For general information about this product, please visit this product's components page here:
https://os.mbed.com/components/PAT9125EL-Evaluation-Board/

For guides and tips on how to setup and evaluate the PAT9125EL sensor with the Nordic nRF52-DK microcontroller using this reference code, please visit this guide:
https://os.mbed.com/teams/PixArt/code/9125_referenceCode/wiki/Guide-for-nRF52-DK-Platform

For guides and tips on how to setup and evaluate the PAT9125EL sensor with any microcontroller using this reference code, please visit this guide:
https://os.mbed.com/teams/PixArt/code/9125_referenceCode/wiki/Guide-for-Any-Platform

commHeaders/SPIcommFunctions.h@5:577976dae20d, 2018-07-23 (annotated)

Committer:
PixArtVY
Date:
Mon Jul 23 22:15:42 2018 +0000
Revision:
5:577976dae20d
Parent:
4:8f7d8ff001f8 
Comments.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
PixArtVY 1:4ea157704c58 1 #define SPImode //Used to check if the sensor is in I2C mode or SPI mode.
PixArtVY 0:e9cce1154246 2
PixArtVY 0:e9cce1154246 3 //=========================================================================
PixArtVY 0:e9cce1154246 4 //Communication pinouts for serial COM port, SPI, and interrupts
PixArtVY 0:e9cce1154246 5 //=========================================================================
PixArtVY 0:e9cce1154246 6 static Serial pc(USBTX, USBRX); //PC comm
PixArtVY 0:e9cce1154246 7 static SPI spi(p23, p24, p25); //mosi, miso, sclk
PixArtVY 0:e9cce1154246 8 static DigitalOut cs(p22); //chip select
PixArtVY 0:e9cce1154246 9
PixArtVY 0:e9cce1154246 10
PixArtVY 0:e9cce1154246 11 //=========================================================================
PixArtVY 0:e9cce1154246 12 //Variables and arrays used for communications and data storage
PixArtVY 0:e9cce1154246 13 //=========================================================================
PixArtVY 0:e9cce1154246 14 int8_t deltaX_low, deltaY_low; //Stores the low-bits of movement data.
PixArtVY 0:e9cce1154246 15 int16_t deltaX_high, deltaY_high; //Stores the high-bits of movement data.
PixArtVY 0:e9cce1154246 16 int16_t deltaX, deltaY; //Stores the combined value of low and high bits.
PixArtVY 0:e9cce1154246 17 int16_t totalX, totalY = 0; //Stores the total deltaX and deltaY moved during runtime.
PixArtVY 0:e9cce1154246 18
PixArtVY 0:e9cce1154246 19
PixArtVY 0:e9cce1154246 20 //=========================================================================
PixArtVY 0:e9cce1154246 21 //Functions used to communicate with the sensor and grab/print data
PixArtVY 0:e9cce1154246 22 //=========================================================================
PixArtVY 0:e9cce1154246 23 uint8_t readRegister(uint8_t addr);
PixArtVY 0:e9cce1154246 24 //This function takes an 8-bit address in the form 0x00 and returns an 8-bit value in the form 0x00.
PixArtVY 0:e9cce1154246 25
PixArtVY 0:e9cce1154246 26 void writeRegister(uint8_t addr, uint8_t data);
PixArtVY 0:e9cce1154246 27 //This function takes an 8-bit address and 8-bit data. Writes the given data to the given address.
PixArtVY 0:e9cce1154246 28
PixArtVY 0:e9cce1154246 29 void load(const uint8_t array[][2], uint8_t arraySize);
PixArtVY 0:e9cce1154246 30 //Takes an array of registers/data (found in registerArrays.h) and their size and writes in all the values.
PixArtVY 0:e9cce1154246 31
PixArtVY 0:e9cce1154246 32 void grabData(void);
PixArtVY 0:e9cce1154246 33 //Grabs the deltaX and deltaY information from the proper registers and formats it into the proper format.
PixArtVY 0:e9cce1154246 34
PixArtVY 0:e9cce1154246 35 void printData(void);
PixArtVY 0:e9cce1154246 36 //Prints the data out to a serial terminal.
PixArtVY 0:e9cce1154246 37
PixArtVY 0:e9cce1154246 38
PixArtVY 0:e9cce1154246 39
PixArtVY 0:e9cce1154246 40
PixArtVY 0:e9cce1154246 41
PixArtVY 0:e9cce1154246 42 //=========================================================================
PixArtVY 0:e9cce1154246 43 //Functions definitions
PixArtVY 0:e9cce1154246 44 //=========================================================================
PixArtVY 0:e9cce1154246 45 uint8_t readRegister(uint8_t addr)
PixArtVY 0:e9cce1154246 46 {
PixArtVY 0:e9cce1154246 47 cs = 0; //Set chip select low/active
PixArtVY 0:e9cce1154246 48 addr = addr & 0x7F; //Set MSB to 0 to indicate read operation
PixArtVY 0:e9cce1154246 49 spi.write(addr); //Write the given address
PixArtVY 0:e9cce1154246 50 uint8_t data_read = spi.write(0x00); //Throw dummy byte after sending address to receieve data
PixArtVY 0:e9cce1154246 51 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:e9cce1154246 52 return data_read; //Returns 8-bit data from register
PixArtVY 0:e9cce1154246 53 }
PixArtVY 0:e9cce1154246 54
PixArtVY 0:e9cce1154246 55
PixArtVY 0:e9cce1154246 56 //=========================================================================
PixArtVY 0:e9cce1154246 57 void writeRegister(uint8_t addr, uint8_t data)
PixArtVY 0:e9cce1154246 58 {
PixArtVY 0:e9cce1154246 59 cs = 0; //Set chip select low/active
PixArtVY 0:e9cce1154246 60 addr = addr | 0x80; //Set MSB to 1 to indicate write operation
PixArtVY 0:e9cce1154246 61 spi.write(addr); //Write the given address
PixArtVY 0:e9cce1154246 62 spi.write(data); //Write the given data
PixArtVY 0:e9cce1154246 63 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:e9cce1154246 64
PixArtVY 0:e9cce1154246 65 //pc.printf("R:%2X, D:%2X\n\r", addr, readRegister(addr));
PixArtVY 0:e9cce1154246 66 //Uncomment this line for debugging. Prints every register write operation.
PixArtVY 0:e9cce1154246 67 }
PixArtVY 0:e9cce1154246 68
PixArtVY 0:e9cce1154246 69
PixArtVY 0:e9cce1154246 70 //=========================================================================
PixArtVY 0:e9cce1154246 71 void load(const uint8_t array[][2], uint8_t arraySize)
PixArtVY 0:e9cce1154246 72 {
PixArtVY 0:e9cce1154246 73 for(uint8_t q = 0; q < arraySize; q++)
PixArtVY 0:e9cce1154246 74 {
PixArtVY 0:e9cce1154246 75 writeRegister(array[q][0], array[q][1]); //Writes the given array of registers/data.
PixArtVY 0:e9cce1154246 76 }
PixArtVY 0:e9cce1154246 77 }
PixArtVY 0:e9cce1154246 78
PixArtVY 0:e9cce1154246 79
PixArtVY 0:e9cce1154246 80 //=========================================================================
PixArtVY 0:e9cce1154246 81 void grabData(void)
PixArtVY 0:e9cce1154246 82 {
PixArtVY 0:e9cce1154246 83 deltaX_low = readRegister(0x03); //Grabs data from the proper registers.
PixArtVY 0:e9cce1154246 84 deltaY_low = readRegister(0x04);
PixArtVY 0:e9cce1154246 85 deltaX_high = (readRegister(0x12)<<4) & 0xF00; //Grabs data and shifts it to make space to be combined with lower bits.
PixArtVY 0:e9cce1154246 86 deltaY_high = (readRegister(0x12)<<8) & 0xF00;
PixArtVY 0:e9cce1154246 87
PixArtVY 0:e9cce1154246 88 if(deltaX_high & 0x800)
PixArtVY 0:e9cce1154246 89 deltaX_high |= 0xf000; // 12-bit data convert to 16-bit (two's comp)
PixArtVY 0:e9cce1154246 90
PixArtVY 0:e9cce1154246 91 if(deltaY_high & 0x800)
PixArtVY 0:e9cce1154246 92 deltaY_high |= 0xf000; // 12-bit data convert to 16-bit (2's comp)
PixArtVY 0:e9cce1154246 93
PixArtVY 0:e9cce1154246 94 deltaX = deltaX_high | deltaX_low; //Combined the low and high bits.
PixArtVY 0:e9cce1154246 95 deltaY = deltaY_high | deltaY_low;
PixArtVY 0:e9cce1154246 96 }
PixArtVY 0:e9cce1154246 97
PixArtVY 0:e9cce1154246 98
PixArtVY 0:e9cce1154246 99 //=========================================================================
PixArtVY 0:e9cce1154246 100 void printData(void)
PixArtVY 0:e9cce1154246 101 {
PixArtVY 0:e9cce1154246 102 if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data.
PixArtVY 0:e9cce1154246 103 {
PixArtVY 0:e9cce1154246 104 totalX += deltaX;
PixArtVY 0:e9cce1154246 105 totalY += deltaY;
PixArtVY 0:e9cce1154246 106
PixArtVY 0:e9cce1154246 107 pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY); //Prints each individual count of deltaX and deltaY.
PixArtVY 3:979019410df2 108 pc.printf("X-axis Counts: %d\t\tY-axis Counts: %d\n\r", totalX, totalY); //Prints the total movement made during runtime.
PixArtVY 0:e9cce1154246 109 }
PixArtVY 0:e9cce1154246 110
PixArtVY 0:e9cce1154246 111 deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
PixArtVY 0:e9cce1154246 112 deltaY = 0;
PixArtVY 0:e9cce1154246 113 }