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
Diff: commHeaders/SPIcommFunctions.h
- Revision:
- 0:e9cce1154246
- Child:
- 1:4ea157704c58
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/commHeaders/SPIcommFunctions.h Fri Feb 23 23:32:40 2018 +0000 @@ -0,0 +1,114 @@ +#define SPImode + +//========================================================================= +//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 load(const uint8_t array[][2], uint8_t arraySize); +//Takes an array of registers/data (found in registerArrays.h) and their size and writes in all the values. + +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(1); //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 load(const uint8_t array[][2], uint8_t arraySize) +{ + for(uint8_t q = 0; q < arraySize; q++) + { + writeRegister(array[q][0], array[q][1]); //Writes the given array of registers/data. + } +} + + +//========================================================================= +void grabData(void) +{ + deltaX_low = readRegister(0x03); //Grabs data from the proper registers. + deltaY_low = readRegister(0x04); + deltaX_high = (readRegister(0x12)<<4) & 0xF00; //Grabs data and shifts it to make space to be combined with lower bits. + deltaY_high = (readRegister(0x12)<<8) & 0xF00; + + if(deltaX_high & 0x800) + deltaX_high |= 0xf000; // 12-bit data convert to 16-bit (two's comp) + + if(deltaY_high & 0x800) + deltaY_high |= 0xf000; // 12-bit data convert to 16-bit (2's comp) + + deltaX = deltaX_high | deltaX_low; //Combined 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\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; +}