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@1:4ea157704c58, 2018-02-28 (annotated)

Committer:
PixArtVY
Date:
Wed Feb 28 21:16:23 2018 +0000
Revision:
1:4ea157704c58
Parent:
0:e9cce1154246
Child:
3:979019410df2
Reference firmware for the 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 program and not as a library.

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 wait_us(1); //Add a tiny delay after sending address for some internal cycle timing.
PixArtVY 0:e9cce1154246 51 uint8_t data_read = spi.write(0x00); //Throw dummy byte after sending address to receieve data
PixArtVY 0:e9cce1154246 52 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:e9cce1154246 53 return data_read; //Returns 8-bit data from register
PixArtVY 0:e9cce1154246 54 }
PixArtVY 0:e9cce1154246 55
PixArtVY 0:e9cce1154246 56
PixArtVY 0:e9cce1154246 57 //=========================================================================
PixArtVY 0:e9cce1154246 58 void writeRegister(uint8_t addr, uint8_t data)
PixArtVY 0:e9cce1154246 59 {
PixArtVY 0:e9cce1154246 60 cs = 0; //Set chip select low/active
PixArtVY 0:e9cce1154246 61 addr = addr | 0x80; //Set MSB to 1 to indicate write operation
PixArtVY 0:e9cce1154246 62 spi.write(addr); //Write the given address
PixArtVY 0:e9cce1154246 63 spi.write(data); //Write the given data
PixArtVY 0:e9cce1154246 64 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:e9cce1154246 65
PixArtVY 0:e9cce1154246 66 //pc.printf("R:%2X, D:%2X\n\r", addr, readRegister(addr));
PixArtVY 0:e9cce1154246 67 //Uncomment this line for debugging. Prints every register write operation.
PixArtVY 0:e9cce1154246 68 }
PixArtVY 0:e9cce1154246 69
PixArtVY 0:e9cce1154246 70
PixArtVY 0:e9cce1154246 71 //=========================================================================
PixArtVY 0:e9cce1154246 72 void load(const uint8_t array[][2], uint8_t arraySize)
PixArtVY 0:e9cce1154246 73 {
PixArtVY 0:e9cce1154246 74 for(uint8_t q = 0; q < arraySize; q++)
PixArtVY 0:e9cce1154246 75 {
PixArtVY 0:e9cce1154246 76 writeRegister(array[q][0], array[q][1]); //Writes the given array of registers/data.
PixArtVY 0:e9cce1154246 77 }
PixArtVY 0:e9cce1154246 78 }
PixArtVY 0:e9cce1154246 79
PixArtVY 0:e9cce1154246 80
PixArtVY 0:e9cce1154246 81 //=========================================================================
PixArtVY 0:e9cce1154246 82 void grabData(void)
PixArtVY 0:e9cce1154246 83 {
PixArtVY 0:e9cce1154246 84 deltaX_low = readRegister(0x03); //Grabs data from the proper registers.
PixArtVY 0:e9cce1154246 85 deltaY_low = readRegister(0x04);
PixArtVY 0:e9cce1154246 86 deltaX_high = (readRegister(0x12)<<4) & 0xF00; //Grabs data and shifts it to make space to be combined with lower bits.
PixArtVY 0:e9cce1154246 87 deltaY_high = (readRegister(0x12)<<8) & 0xF00;
PixArtVY 0:e9cce1154246 88
PixArtVY 0:e9cce1154246 89 if(deltaX_high & 0x800)
PixArtVY 0:e9cce1154246 90 deltaX_high |= 0xf000; // 12-bit data convert to 16-bit (two's comp)
PixArtVY 0:e9cce1154246 91
PixArtVY 0:e9cce1154246 92 if(deltaY_high & 0x800)
PixArtVY 0:e9cce1154246 93 deltaY_high |= 0xf000; // 12-bit data convert to 16-bit (2's comp)
PixArtVY 0:e9cce1154246 94
PixArtVY 0:e9cce1154246 95 deltaX = deltaX_high | deltaX_low; //Combined the low and high bits.
PixArtVY 0:e9cce1154246 96 deltaY = deltaY_high | deltaY_low;
PixArtVY 0:e9cce1154246 97 }
PixArtVY 0:e9cce1154246 98
PixArtVY 0:e9cce1154246 99
PixArtVY 0:e9cce1154246 100 //=========================================================================
PixArtVY 0:e9cce1154246 101 void printData(void)
PixArtVY 0:e9cce1154246 102 {
PixArtVY 0:e9cce1154246 103 if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data.
PixArtVY 0:e9cce1154246 104 {
PixArtVY 0:e9cce1154246 105 totalX += deltaX;
PixArtVY 0:e9cce1154246 106 totalY += deltaY;
PixArtVY 0:e9cce1154246 107
PixArtVY 0:e9cce1154246 108 pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY); //Prints each individual count of deltaX and deltaY.
PixArtVY 0:e9cce1154246 109 pc.printf("X-axis Counts: %d\t\t\tY-axis Counts: %d\n\r", totalX, totalY); //Prints the total movement made during runtime.
PixArtVY 0:e9cce1154246 110 }
PixArtVY 0:e9cce1154246 111
PixArtVY 0:e9cce1154246 112 deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
PixArtVY 0:e9cce1154246 113 deltaY = 0;
PixArtVY 0:e9cce1154246 114 }