PixArt / Mbed OS 5101_referenceCode

Reference firmware for PixArt's PAA5101 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 PAA5101 sensor and evaluation board.

For general information about this product, please visit this product's components page here:
https://os.mbed.com/components/PAA5101-Floor-Tracking-Sensor-with-Wide-/

For guides and tips on how to setup and evaluate the PAA5101 sensor with the Nordic nRF52-DK microcontroller using this reference code, please visit this guide:
https://os.mbed.com/teams/PixArt/code/5101_referenceCode/wiki/Guide-for-nRF52-DK-Platform

For guides and tips on how to setup and evaluate the PAA5101 sensor with any microcontroller using this reference code, please visit this guide:
https://os.mbed.com/teams/PixArt/code/5101_referenceCode/wiki/Guide-for-Any-Platform

commHeaders/SPIcommFunctions.h@5:e6cc13f2fc8b, 2018-07-18 (annotated)

Committer:
PixArtVY
Date:
Wed Jul 18 18:36:47 2018 +0000
Revision:
5:e6cc13f2fc8b
Parent:
3:1d5c2956f415 
Added Apache License notice.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
PixArtVY 0:2c144b6813d1 1 //=========================================================================
PixArtVY 0:2c144b6813d1 2 //Communication pinouts for serial COM port, SPI, and interrupts
PixArtVY 0:2c144b6813d1 3 //=========================================================================
PixArtVY 0:2c144b6813d1 4 static Serial pc(USBTX, USBRX); //PC serial communication.
PixArtVY 0:2c144b6813d1 5 static SPI spi(p23, p24, p25); //MOSI, MISO, SCLK (because this is 3-Wire SPI, we tie MOSI and MISO together on the SDIO pin, but separate them when we get to the MCU).
PixArtVY 0:2c144b6813d1 6 static DigitalOut cs(p22); //Chip select pin.
PixArtVY 0:2c144b6813d1 7 static DigitalOut LDP(p20); //Laser diode pin.
PixArtVY 0:2c144b6813d1 8
PixArtVY 0:2c144b6813d1 9
PixArtVY 0:2c144b6813d1 10 //=========================================================================
PixArtVY 0:2c144b6813d1 11 //Variables and arrays used for communications and data storage
PixArtVY 0:2c144b6813d1 12 //=========================================================================
PixArtVY 0:2c144b6813d1 13 int16_t deltaX = 0; //Stores X-axis output data.
PixArtVY 0:2c144b6813d1 14 int16_t deltaY = 0; //Stores Y-axis output data.
PixArtVY 1:469063631a05 15 int16_t totalX, totalY = 0; //Stores the total deltaX and deltaY moved during runtime.
PixArtVY 0:2c144b6813d1 16 uint8_t frameCounter = 0; //Looping variable to track when we have grabbed 8 frames of data.
PixArtVY 0:2c144b6813d1 17 uint16_t imageQuality[8]; //Stores 8 frames of image data to determine when quality changes to a point where we need to switch modes (LED/laser).
PixArtVY 0:2c144b6813d1 18 uint16_t imageQuality_total = 0; //Stores the sum of all raw values from the 8 frames from imageQuality[8].
PixArtVY 0:2c144b6813d1 19 uint8_t mode = 0; //Modes: 0 = Laser, 1 = LED. Laser is default.
PixArtVY 0:2c144b6813d1 20 #define laser2LED_threshold 0x700 //Stores threshold level for when we need to swap to LED mode.
PixArtVY 0:2c144b6813d1 21 #define LED2laser_threshold 0x500 //Stores threshold level for when we need to swap to laser mode.
PixArtVY 0:2c144b6813d1 22
PixArtVY 0:2c144b6813d1 23 uint8_t currentBank; //Stores current register bank.
PixArtVY 0:2c144b6813d1 24
PixArtVY 0:2c144b6813d1 25
PixArtVY 0:2c144b6813d1 26 //=========================================================================
PixArtVY 0:2c144b6813d1 27 //Functions used to communicate with the sensor and grab/print data
PixArtVY 0:2c144b6813d1 28 //=========================================================================
PixArtVY 0:2c144b6813d1 29 uint8_t readRegister(uint8_t addr);
PixArtVY 0:2c144b6813d1 30 //This function takes an 8-bit address in the form 0x00 and returns an 8-bit value in the form 0x00.
PixArtVY 0:2c144b6813d1 31
PixArtVY 0:2c144b6813d1 32 void writeRegister(uint8_t addr, uint8_t data);
PixArtVY 0:2c144b6813d1 33 //This function takes an 8-bit address and 8-bit data. Writes the given data to the given address.
PixArtVY 0:2c144b6813d1 34
PixArtVY 0:2c144b6813d1 35 void load(const uint8_t array[][2], uint8_t arraySize);
PixArtVY 0:2c144b6813d1 36 //Takes an array of registers/data (found in registerArrays.h) and their size and writes in all the values.
PixArtVY 0:2c144b6813d1 37
PixArtVY 0:2c144b6813d1 38 void checkMode(void);
PixArtVY 0:2c144b6813d1 39 //This function checks the image quality of each frame and switches between LED and laser modes when necessary.
PixArtVY 0:2c144b6813d1 40
PixArtVY 0:2c144b6813d1 41 void grabData(void);
PixArtVY 0:2c144b6813d1 42 //Takes data from the sensor and stores it into variables deltaX and deltaY.
PixArtVY 0:2c144b6813d1 43
PixArtVY 0:2c144b6813d1 44 void printData(void);
PixArtVY 0:2c144b6813d1 45 //Prints the deltaX and deltaY values to a serial terminal whenever the values change.
PixArtVY 0:2c144b6813d1 46
PixArtVY 0:2c144b6813d1 47
PixArtVY 0:2c144b6813d1 48
PixArtVY 0:2c144b6813d1 49
PixArtVY 0:2c144b6813d1 50
PixArtVY 0:2c144b6813d1 51 //=========================================================================
PixArtVY 0:2c144b6813d1 52 //Functions definitions
PixArtVY 0:2c144b6813d1 53 //=========================================================================
PixArtVY 0:2c144b6813d1 54 uint8_t readRegister(uint8_t addr)
PixArtVY 0:2c144b6813d1 55 {
PixArtVY 0:2c144b6813d1 56 cs = 0; //Set chip select low/active
PixArtVY 0:2c144b6813d1 57 addr = addr & 0x7F; //Set MSB to 0 to indicate read operation
PixArtVY 0:2c144b6813d1 58 spi.write(addr); //Write the given address
PixArtVY 0:2c144b6813d1 59 wait_ms(1);
PixArtVY 0:2c144b6813d1 60 uint8_t data_read = spi.write(0x00); //Throw dummy byte after sending address to receieve data
PixArtVY 0:2c144b6813d1 61 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:2c144b6813d1 62 return data_read; //Returns 8-bit data from register
PixArtVY 0:2c144b6813d1 63 }
PixArtVY 0:2c144b6813d1 64
PixArtVY 0:2c144b6813d1 65
PixArtVY 0:2c144b6813d1 66 //=========================================================================
PixArtVY 0:2c144b6813d1 67 void writeRegister(uint8_t addr, uint8_t data)
PixArtVY 0:2c144b6813d1 68 {
PixArtVY 0:2c144b6813d1 69 cs = 0; //Set chip select low/active
PixArtVY 0:2c144b6813d1 70 addr = addr | 0x80; //Set MSB to 1 to indicate write operation
PixArtVY 0:2c144b6813d1 71 spi.write(addr); //Write the given address
PixArtVY 0:2c144b6813d1 72 spi.write(data); //Write the given data
PixArtVY 0:2c144b6813d1 73 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:2c144b6813d1 74
PixArtVY 0:2c144b6813d1 75 if(addr == 0x7F) //You can't read register 0x7F for the current bank so we store the value before writing it
PixArtVY 0:2c144b6813d1 76 {
PixArtVY 0:2c144b6813d1 77 currentBank = data; //Store the current bank for printing later.
PixArtVY 0:2c144b6813d1 78 //pc.printf("B:%2X, R:%2X, D:%2X\n\r", currentBank, (addr & 0x7F), currentBank);
PixArtVY 0:2c144b6813d1 79 //Uncomment this line and the other print line below for debugging. Prints every register bank change.
PixArtVY 0:2c144b6813d1 80 }
PixArtVY 0:2c144b6813d1 81
PixArtVY 0:2c144b6813d1 82 else
PixArtVY 0:2c144b6813d1 83 {
PixArtVY 0:2c144b6813d1 84 //pc.printf("B:%2X, R:%2X, D:%2X\n\r", currentBank, (addr & 0x7F), readRegister(addr));
PixArtVY 0:2c144b6813d1 85 //Uncomment this line and the other print line above for debugging. Prints every register write operation.
PixArtVY 0:2c144b6813d1 86 }
PixArtVY 0:2c144b6813d1 87 }
PixArtVY 0:2c144b6813d1 88
PixArtVY 0:2c144b6813d1 89
PixArtVY 0:2c144b6813d1 90 //=========================================================================
PixArtVY 0:2c144b6813d1 91 void load(const uint8_t array[][2], uint8_t arraySize)
PixArtVY 0:2c144b6813d1 92 {
PixArtVY 0:2c144b6813d1 93 for(uint8_t q = 0; q < arraySize; q++)
PixArtVY 0:2c144b6813d1 94 {
PixArtVY 0:2c144b6813d1 95 writeRegister(array[q][0], array[q][1]); //Writes the given array of registers/data.
PixArtVY 0:2c144b6813d1 96 }
PixArtVY 0:2c144b6813d1 97 }
PixArtVY 0:2c144b6813d1 98
PixArtVY 0:2c144b6813d1 99
PixArtVY 0:2c144b6813d1 100 //=========================================================================
PixArtVY 0:2c144b6813d1 101 void checkMode(void)
PixArtVY 0:2c144b6813d1 102 {
PixArtVY 0:2c144b6813d1 103 uint16_t data_msb, data_lsb = 0; //These variables store the high and low bits of image quality data.
PixArtVY 0:2c144b6813d1 104 imageQuality_total = 0; //This variable holds the sum of 8 frames of data.
PixArtVY 0:2c144b6813d1 105
PixArtVY 0:2c144b6813d1 106 data_msb = readRegister(0x75); //Reads upper 8 bits of image quality.
PixArtVY 0:2c144b6813d1 107 data_lsb = readRegister(0x76); //Reads lower 8 bits of image quality.
PixArtVY 0:2c144b6813d1 108 imageQuality[frameCounter] = data_msb*256 + data_lsb; //Combines the low/high bits to be a single element in this array.
PixArtVY 0:2c144b6813d1 109
PixArtVY 0:2c144b6813d1 110 if(frameCounter == 7) //We check image quality every EIGHT samples before determining if a mode-switch is necessary.
PixArtVY 0:2c144b6813d1 111 {
PixArtVY 0:2c144b6813d1 112 for(int i=0; i<8; i++) //Sums up 8 frames of image quality data into 1 variable.
PixArtVY 0:2c144b6813d1 113 {
PixArtVY 0:2c144b6813d1 114 imageQuality_total = imageQuality_total + imageQuality[i];
PixArtVY 0:2c144b6813d1 115 }
PixArtVY 0:2c144b6813d1 116
PixArtVY 1:469063631a05 117 if(mode == 1 && imageQuality_total < LED2laser_threshold) //Check the condition for when we need to change to laser.
PixArtVY 0:2c144b6813d1 118 {
PixArtVY 1:469063631a05 119 load(modeLaser, modeLaser_size); //Loads the register array that has the settings for laser mode.
PixArtVY 1:469063631a05 120 mode = 0; //Sets the mode-tracker to be 0 to reflect laser mode.
PixArtVY 1:469063631a05 121 LDP = 0; //Sets the laser diode GPIO pin to be LOW (active because of PMOS pull-up).
PixArtVY 1:469063631a05 122 wait_ms(40); //Delay for timing.
PixArtVY 1:469063631a05 123 writeRegister(0x03, 0x00); //Unlisted...
PixArtVY 0:2c144b6813d1 124
PixArtVY 1:469063631a05 125 //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
PixArtVY 1:469063631a05 126 //pc.printf("Now in laser mode. Value of 'mode': %1X\n\r", mode);
PixArtVY 1:469063631a05 127 //Uncomment these lines and the other print lines below for debugging. Prints image quality and tracks mode-switches.
PixArtVY 0:2c144b6813d1 128 }
PixArtVY 0:2c144b6813d1 129
PixArtVY 1:469063631a05 130 if(mode == 0 && imageQuality_total < laser2LED_threshold) //Check the condition for when we need to change to LED.
PixArtVY 0:2c144b6813d1 131 {
PixArtVY 1:469063631a05 132 load(modeLED, modeLED_size); //Loads the register array that has the settings for LED mode.
PixArtVY 1:469063631a05 133 mode = 1; //Sets the mode-tracker to be 1 to reflect LED mode.
PixArtVY 1:469063631a05 134 LDP = 1; //Sets the laser diode GPIO pin to be HIGH (inactive because of PMOS pull-up).
PixArtVY 1:469063631a05 135 wait_ms(40); //Delay for timing.
PixArtVY 1:469063631a05 136 writeRegister(0x03, 0x00); //Unlisted...
PixArtVY 0:2c144b6813d1 137
PixArtVY 1:469063631a05 138 //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
PixArtVY 1:469063631a05 139 //pc.printf("Now in LED mode. Value of 'mode': %1X\n\r", mode);
PixArtVY 1:469063631a05 140 //Uncomment these lines and the other print lines above for debugging. Prints image quality and tracks mode-switches.
PixArtVY 0:2c144b6813d1 141 }
PixArtVY 0:2c144b6813d1 142 }
PixArtVY 0:2c144b6813d1 143
PixArtVY 0:2c144b6813d1 144 frameCounter = (frameCounter + 1) & 0x07; //This variable loops from zero to 7 without using a looper or variable. Every time this function is called, it moves up 1 towards 7 or resets to zero.
PixArtVY 0:2c144b6813d1 145 }
PixArtVY 0:2c144b6813d1 146
PixArtVY 0:2c144b6813d1 147
PixArtVY 0:2c144b6813d1 148 //=========================================================================
PixArtVY 0:2c144b6813d1 149 void grabData(void)
PixArtVY 0:2c144b6813d1 150 {
PixArtVY 0:2c144b6813d1 151 int16_t deltaX_high, deltaX_low = 0; //These four variables store the low/high bits of the deltaX and deltaY data.
PixArtVY 0:2c144b6813d1 152 int16_t deltaY_high, deltaY_low = 0;
PixArtVY 0:2c144b6813d1 153
PixArtVY 0:2c144b6813d1 154 deltaX_low = (int16_t)readRegister(0x03); //Grabbing the data from registers.
PixArtVY 0:2c144b6813d1 155 deltaY_low = (int16_t)readRegister(0x04);
PixArtVY 0:2c144b6813d1 156 deltaX_high = ((int16_t)readRegister(0x11))<<8; //Shifts high bits left by 8 so that we can combine high and low bytes together.
PixArtVY 0:2c144b6813d1 157 deltaY_high = ((int16_t)readRegister(0x12))<<8;
PixArtVY 0:2c144b6813d1 158
PixArtVY 0:2c144b6813d1 159 deltaX = deltaX_high | deltaX_low; //Combines the low/high bits of X and Y to be one variable.
PixArtVY 0:2c144b6813d1 160 deltaY = deltaY_high | deltaY_low;
PixArtVY 0:2c144b6813d1 161 }
PixArtVY 0:2c144b6813d1 162
PixArtVY 0:2c144b6813d1 163
PixArtVY 0:2c144b6813d1 164 //=========================================================================
PixArtVY 0:2c144b6813d1 165 void printData(void)
PixArtVY 0:2c144b6813d1 166 {
PixArtVY 0:2c144b6813d1 167 if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data.
PixArtVY 0:2c144b6813d1 168 {
PixArtVY 1:469063631a05 169 totalX += deltaX;
PixArtVY 1:469063631a05 170 totalY += deltaY;
PixArtVY 1:469063631a05 171
PixArtVY 1:469063631a05 172 pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY); //Prints each individual count of deltaX and deltaY.
PixArtVY 1:469063631a05 173 pc.printf("X-axis Counts: %d\t\tY-axis Counts: %d\n\r", totalX, totalY); //Prints the total movement made during runtime.
PixArtVY 0:2c144b6813d1 174 }
PixArtVY 0:2c144b6813d1 175
PixArtVY 0:2c144b6813d1 176 deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
PixArtVY 0:2c144b6813d1 177 deltaY = 0;
PixArtVY 0:2c144b6813d1 178 }