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@0:2c144b6813d1, 2018-03-19 (annotated)

Committer:
PixArtVY
Date:
Mon Mar 19 21:18:40 2018 +0000
Revision:
0:2c144b6813d1
Child:
1:469063631a05
First release.

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 0:2c144b6813d1 15
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 imageQualityOK = 0;
PixArtVY 0:2c144b6813d1 20 uint8_t mode = 0; //Modes: 0 = Laser, 1 = LED. Laser is default.
PixArtVY 0:2c144b6813d1 21 #define laser2LED_threshold 0x700 //Stores threshold level for when we need to swap to LED mode.
PixArtVY 0:2c144b6813d1 22 #define LED2laser_threshold 0x500 //Stores threshold level for when we need to swap to laser mode.
PixArtVY 0:2c144b6813d1 23
PixArtVY 0:2c144b6813d1 24 uint8_t currentBank; //Stores current register bank.
PixArtVY 0:2c144b6813d1 25
PixArtVY 0:2c144b6813d1 26
PixArtVY 0:2c144b6813d1 27 //=========================================================================
PixArtVY 0:2c144b6813d1 28 //Functions used to communicate with the sensor and grab/print data
PixArtVY 0:2c144b6813d1 29 //=========================================================================
PixArtVY 0:2c144b6813d1 30 uint8_t readRegister(uint8_t addr);
PixArtVY 0:2c144b6813d1 31 //This function takes an 8-bit address in the form 0x00 and returns an 8-bit value in the form 0x00.
PixArtVY 0:2c144b6813d1 32
PixArtVY 0:2c144b6813d1 33 void writeRegister(uint8_t addr, uint8_t data);
PixArtVY 0:2c144b6813d1 34 //This function takes an 8-bit address and 8-bit data. Writes the given data to the given address.
PixArtVY 0:2c144b6813d1 35
PixArtVY 0:2c144b6813d1 36 void load(const uint8_t array[][2], uint8_t arraySize);
PixArtVY 0:2c144b6813d1 37 //Takes an array of registers/data (found in registerArrays.h) and their size and writes in all the values.
PixArtVY 0:2c144b6813d1 38
PixArtVY 0:2c144b6813d1 39 void checkMode(void);
PixArtVY 0:2c144b6813d1 40 //This function checks the image quality of each frame and switches between LED and laser modes when necessary.
PixArtVY 0:2c144b6813d1 41
PixArtVY 0:2c144b6813d1 42 void grabData(void);
PixArtVY 0:2c144b6813d1 43 //Takes data from the sensor and stores it into variables deltaX and deltaY.
PixArtVY 0:2c144b6813d1 44
PixArtVY 0:2c144b6813d1 45 void printData(void);
PixArtVY 0:2c144b6813d1 46 //Prints the deltaX and deltaY values to a serial terminal whenever the values change.
PixArtVY 0:2c144b6813d1 47
PixArtVY 0:2c144b6813d1 48
PixArtVY 0:2c144b6813d1 49
PixArtVY 0:2c144b6813d1 50
PixArtVY 0:2c144b6813d1 51
PixArtVY 0:2c144b6813d1 52 //=========================================================================
PixArtVY 0:2c144b6813d1 53 //Functions definitions
PixArtVY 0:2c144b6813d1 54 //=========================================================================
PixArtVY 0:2c144b6813d1 55 uint8_t readRegister(uint8_t addr)
PixArtVY 0:2c144b6813d1 56 {
PixArtVY 0:2c144b6813d1 57 cs = 0; //Set chip select low/active
PixArtVY 0:2c144b6813d1 58 addr = addr & 0x7F; //Set MSB to 0 to indicate read operation
PixArtVY 0:2c144b6813d1 59 spi.write(addr); //Write the given address
PixArtVY 0:2c144b6813d1 60 wait_ms(1);
PixArtVY 0:2c144b6813d1 61 uint8_t data_read = spi.write(0x00); //Throw dummy byte after sending address to receieve data
PixArtVY 0:2c144b6813d1 62 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:2c144b6813d1 63 return data_read; //Returns 8-bit data from register
PixArtVY 0:2c144b6813d1 64 }
PixArtVY 0:2c144b6813d1 65
PixArtVY 0:2c144b6813d1 66
PixArtVY 0:2c144b6813d1 67 //=========================================================================
PixArtVY 0:2c144b6813d1 68 void writeRegister(uint8_t addr, uint8_t data)
PixArtVY 0:2c144b6813d1 69 {
PixArtVY 0:2c144b6813d1 70 cs = 0; //Set chip select low/active
PixArtVY 0:2c144b6813d1 71 addr = addr | 0x80; //Set MSB to 1 to indicate write operation
PixArtVY 0:2c144b6813d1 72 spi.write(addr); //Write the given address
PixArtVY 0:2c144b6813d1 73 spi.write(data); //Write the given data
PixArtVY 0:2c144b6813d1 74 cs = 1; //Set chip select back to high/inactive
PixArtVY 0:2c144b6813d1 75
PixArtVY 0:2c144b6813d1 76 if(addr == 0x7F) //You can't read register 0x7F for the current bank so we store the value before writing it
PixArtVY 0:2c144b6813d1 77 {
PixArtVY 0:2c144b6813d1 78 currentBank = data; //Store the current bank for printing later.
PixArtVY 0:2c144b6813d1 79 //pc.printf("B:%2X, R:%2X, D:%2X\n\r", currentBank, (addr & 0x7F), currentBank);
PixArtVY 0:2c144b6813d1 80 //Uncomment this line and the other print line below for debugging. Prints every register bank change.
PixArtVY 0:2c144b6813d1 81 }
PixArtVY 0:2c144b6813d1 82
PixArtVY 0:2c144b6813d1 83 else
PixArtVY 0:2c144b6813d1 84 {
PixArtVY 0:2c144b6813d1 85 //pc.printf("B:%2X, R:%2X, D:%2X\n\r", currentBank, (addr & 0x7F), readRegister(addr));
PixArtVY 0:2c144b6813d1 86 //Uncomment this line and the other print line above for debugging. Prints every register write operation.
PixArtVY 0:2c144b6813d1 87 }
PixArtVY 0:2c144b6813d1 88
PixArtVY 0:2c144b6813d1 89 wait_ms(2);
PixArtVY 0:2c144b6813d1 90 }
PixArtVY 0:2c144b6813d1 91
PixArtVY 0:2c144b6813d1 92
PixArtVY 0:2c144b6813d1 93 //=========================================================================
PixArtVY 0:2c144b6813d1 94 void load(const uint8_t array[][2], uint8_t arraySize)
PixArtVY 0:2c144b6813d1 95 {
PixArtVY 0:2c144b6813d1 96 for(uint8_t q = 0; q < arraySize; q++)
PixArtVY 0:2c144b6813d1 97 {
PixArtVY 0:2c144b6813d1 98 writeRegister(array[q][0], array[q][1]); //Writes the given array of registers/data.
PixArtVY 0:2c144b6813d1 99 }
PixArtVY 0:2c144b6813d1 100 }
PixArtVY 0:2c144b6813d1 101
PixArtVY 0:2c144b6813d1 102
PixArtVY 0:2c144b6813d1 103 //=========================================================================
PixArtVY 0:2c144b6813d1 104 void checkMode(void)
PixArtVY 0:2c144b6813d1 105 {
PixArtVY 0:2c144b6813d1 106 uint16_t data_msb, data_lsb = 0; //These variables store the high and low bits of image quality data.
PixArtVY 0:2c144b6813d1 107 imageQuality_total = 0; //This variable holds the sum of 8 frames of data.
PixArtVY 0:2c144b6813d1 108
PixArtVY 0:2c144b6813d1 109 data_msb = readRegister(0x75); //Reads upper 8 bits of image quality.
PixArtVY 0:2c144b6813d1 110 data_lsb = readRegister(0x76); //Reads lower 8 bits of image quality.
PixArtVY 0:2c144b6813d1 111 imageQuality[frameCounter] = data_msb*256 + data_lsb; //Combines the low/high bits to be a single element in this array.
PixArtVY 0:2c144b6813d1 112
PixArtVY 0:2c144b6813d1 113 if(frameCounter == 7) //We check image quality every EIGHT samples before determining if a mode-switch is necessary.
PixArtVY 0:2c144b6813d1 114 {
PixArtVY 0:2c144b6813d1 115 for(int i=0; i<8; i++) //Sums up 8 frames of image quality data into 1 variable.
PixArtVY 0:2c144b6813d1 116 {
PixArtVY 0:2c144b6813d1 117 imageQuality_total = imageQuality_total + imageQuality[i];
PixArtVY 0:2c144b6813d1 118 }
PixArtVY 0:2c144b6813d1 119
PixArtVY 0:2c144b6813d1 120 if(imageQualityOK == 0 && imageQuality_total > LED2laser_threshold) //If imageQuality is over 0x500, we can continue to select the proper mode.
PixArtVY 0:2c144b6813d1 121 {
PixArtVY 0:2c144b6813d1 122 imageQualityOK = 1;
PixArtVY 0:2c144b6813d1 123
PixArtVY 0:2c144b6813d1 124 }
PixArtVY 0:2c144b6813d1 125
PixArtVY 0:2c144b6813d1 126 if(mode == 0 && imageQuality_total < LED2laser_threshold) //If image quality is too low even with brighter laser setting, LED/laser states will keep oscillating and sensor can't function.
PixArtVY 0:2c144b6813d1 127 {
PixArtVY 0:2c144b6813d1 128 imageQualityOK = 0;
PixArtVY 0:2c144b6813d1 129 pc.printf("Image quality too low! Value: %4X\n\r", imageQuality_total);
PixArtVY 0:2c144b6813d1 130 }
PixArtVY 0:2c144b6813d1 131
PixArtVY 0:2c144b6813d1 132
PixArtVY 0:2c144b6813d1 133 if(imageQualityOK)
PixArtVY 0:2c144b6813d1 134 {
PixArtVY 0:2c144b6813d1 135 pc.printf("Image quality OK! Value: %4X\n\r", imageQuality_total);
PixArtVY 0:2c144b6813d1 136
PixArtVY 0:2c144b6813d1 137 if(mode == 1 && imageQuality_total < LED2laser_threshold) //Check the condition for when we need to change to laser.
PixArtVY 0:2c144b6813d1 138 {
PixArtVY 0:2c144b6813d1 139 load(modeLaser, modeLaser_size); //Loads the register array that has the settings for laser mode.
PixArtVY 0:2c144b6813d1 140 mode = 0; //Sets the mode-tracker to be 0 to reflect laser mode.
PixArtVY 0:2c144b6813d1 141 LDP = 0; //Sets the laser diode GPIO pin to be LOW (active because of PMOS pull-up).
PixArtVY 0:2c144b6813d1 142 wait_ms(40); //Delay for timing.
PixArtVY 0:2c144b6813d1 143 writeRegister(0x03, 0x00); //Delta_XL?????? TRY TO FIND OUT WHAT THIS REGISTER IS FOR**********************************************************
PixArtVY 0:2c144b6813d1 144
PixArtVY 0:2c144b6813d1 145 //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
PixArtVY 0:2c144b6813d1 146 //pc.printf("Now in laser mode. Value of 'mode': %1X\n\r", mode);
PixArtVY 0:2c144b6813d1 147 //Uncomment these lines and the other print lines below for debugging. Prints image quality and tracks mode-switches.
PixArtVY 0:2c144b6813d1 148 }
PixArtVY 0:2c144b6813d1 149
PixArtVY 0:2c144b6813d1 150 if(mode == 0 && imageQuality_total < laser2LED_threshold) //Check the condition for when we need to change to LED.
PixArtVY 0:2c144b6813d1 151 {
PixArtVY 0:2c144b6813d1 152 load(modeLED, modeLED_size); //Loads the register array that has the settings for LED mode.
PixArtVY 0:2c144b6813d1 153 mode = 1; //Sets the mode-tracker to be 1 to reflect LED mode.
PixArtVY 0:2c144b6813d1 154 LDP = 1; //Sets the laser diode GPIO pin to be HIGH (inactive because of PMOS pull-up).
PixArtVY 0:2c144b6813d1 155 wait_ms(40); //Delay for timing.
PixArtVY 0:2c144b6813d1 156 writeRegister(0x03, 0x00); //Delta_XL?????? TRY TO FIND OUT WHAT THIS REGISTER IS FOR**********************************************************
PixArtVY 0:2c144b6813d1 157
PixArtVY 0:2c144b6813d1 158 //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
PixArtVY 0:2c144b6813d1 159 //pc.printf("Now in LED mode. Value of 'mode': %1X\n\r", mode);
PixArtVY 0:2c144b6813d1 160 //Uncomment these lines and the other print lines above for debugging. Prints image quality and tracks mode-switches.
PixArtVY 0:2c144b6813d1 161 }
PixArtVY 0:2c144b6813d1 162 }
PixArtVY 0:2c144b6813d1 163 }
PixArtVY 0:2c144b6813d1 164
PixArtVY 0:2c144b6813d1 165 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 166 }
PixArtVY 0:2c144b6813d1 167
PixArtVY 0:2c144b6813d1 168
PixArtVY 0:2c144b6813d1 169 //=========================================================================
PixArtVY 0:2c144b6813d1 170 void grabData(void)
PixArtVY 0:2c144b6813d1 171 {
PixArtVY 0:2c144b6813d1 172 int16_t deltaX_high, deltaX_low = 0; //These four variables store the low/high bits of the deltaX and deltaY data.
PixArtVY 0:2c144b6813d1 173 int16_t deltaY_high, deltaY_low = 0;
PixArtVY 0:2c144b6813d1 174
PixArtVY 0:2c144b6813d1 175 deltaX_low = (int16_t)readRegister(0x03); //Grabbing the data from registers.
PixArtVY 0:2c144b6813d1 176 deltaY_low = (int16_t)readRegister(0x04);
PixArtVY 0:2c144b6813d1 177 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 178 deltaY_high = ((int16_t)readRegister(0x12))<<8;
PixArtVY 0:2c144b6813d1 179
PixArtVY 0:2c144b6813d1 180 deltaX = deltaX_high | deltaX_low; //Combines the low/high bits of X and Y to be one variable.
PixArtVY 0:2c144b6813d1 181 deltaY = deltaY_high | deltaY_low;
PixArtVY 0:2c144b6813d1 182 }
PixArtVY 0:2c144b6813d1 183
PixArtVY 0:2c144b6813d1 184
PixArtVY 0:2c144b6813d1 185 //=========================================================================
PixArtVY 0:2c144b6813d1 186 void printData(void)
PixArtVY 0:2c144b6813d1 187 {
PixArtVY 0:2c144b6813d1 188 if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data.
PixArtVY 0:2c144b6813d1 189 {
PixArtVY 0:2c144b6813d1 190 pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY);
PixArtVY 0:2c144b6813d1 191 }
PixArtVY 0:2c144b6813d1 192
PixArtVY 0:2c144b6813d1 193 deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
PixArtVY 0:2c144b6813d1 194 deltaY = 0;
PixArtVY 0:2c144b6813d1 195 }