PixArt / Mbed OS 5101_referenceCode

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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@2:045cc9f995ae, 2018-06-01 (annotated)

Committer:
PixArtVY
Date:
Fri Jun 01 21:37:39 2018 +0000
Revision:
2:045cc9f995ae
Parent:
1:469063631a05
Child:
3:1d5c2956f415
Removed some unnecessary variables.

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 wait_ms(2);
PixArtVY 0:2c144b6813d1 89 }
PixArtVY 0:2c144b6813d1 90
PixArtVY 0:2c144b6813d1 91
PixArtVY 0:2c144b6813d1 92 //=========================================================================
PixArtVY 0:2c144b6813d1 93 void load(const uint8_t array[][2], uint8_t arraySize)
PixArtVY 0:2c144b6813d1 94 {
PixArtVY 0:2c144b6813d1 95 for(uint8_t q = 0; q < arraySize; q++)
PixArtVY 0:2c144b6813d1 96 {
PixArtVY 0:2c144b6813d1 97 writeRegister(array[q][0], array[q][1]); //Writes the given array of registers/data.
PixArtVY 0:2c144b6813d1 98 }
PixArtVY 0:2c144b6813d1 99 }
PixArtVY 0:2c144b6813d1 100
PixArtVY 0:2c144b6813d1 101
PixArtVY 0:2c144b6813d1 102 //=========================================================================
PixArtVY 0:2c144b6813d1 103 void checkMode(void)
PixArtVY 0:2c144b6813d1 104 {
PixArtVY 0:2c144b6813d1 105 uint16_t data_msb, data_lsb = 0; //These variables store the high and low bits of image quality data.
PixArtVY 0:2c144b6813d1 106 imageQuality_total = 0; //This variable holds the sum of 8 frames of data.
PixArtVY 0:2c144b6813d1 107
PixArtVY 0:2c144b6813d1 108 data_msb = readRegister(0x75); //Reads upper 8 bits of image quality.
PixArtVY 0:2c144b6813d1 109 data_lsb = readRegister(0x76); //Reads lower 8 bits of image quality.
PixArtVY 0:2c144b6813d1 110 imageQuality[frameCounter] = data_msb*256 + data_lsb; //Combines the low/high bits to be a single element in this array.
PixArtVY 0:2c144b6813d1 111
PixArtVY 0:2c144b6813d1 112 if(frameCounter == 7) //We check image quality every EIGHT samples before determining if a mode-switch is necessary.
PixArtVY 0:2c144b6813d1 113 {
PixArtVY 0:2c144b6813d1 114 for(int i=0; i<8; i++) //Sums up 8 frames of image quality data into 1 variable.
PixArtVY 0:2c144b6813d1 115 {
PixArtVY 0:2c144b6813d1 116 imageQuality_total = imageQuality_total + imageQuality[i];
PixArtVY 0:2c144b6813d1 117 }
PixArtVY 0:2c144b6813d1 118
PixArtVY 1:469063631a05 119 if(mode == 1 && imageQuality_total < LED2laser_threshold) //Check the condition for when we need to change to laser.
PixArtVY 0:2c144b6813d1 120 {
PixArtVY 1:469063631a05 121 load(modeLaser, modeLaser_size); //Loads the register array that has the settings for laser mode.
PixArtVY 1:469063631a05 122 mode = 0; //Sets the mode-tracker to be 0 to reflect laser mode.
PixArtVY 1:469063631a05 123 LDP = 0; //Sets the laser diode GPIO pin to be LOW (active because of PMOS pull-up).
PixArtVY 1:469063631a05 124 wait_ms(40); //Delay for timing.
PixArtVY 1:469063631a05 125 writeRegister(0x03, 0x00); //Unlisted...
PixArtVY 0:2c144b6813d1 126
PixArtVY 1:469063631a05 127 //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
PixArtVY 1:469063631a05 128 //pc.printf("Now in laser mode. Value of 'mode': %1X\n\r", mode);
PixArtVY 1:469063631a05 129 //Uncomment these lines and the other print lines below for debugging. Prints image quality and tracks mode-switches.
PixArtVY 0:2c144b6813d1 130 }
PixArtVY 0:2c144b6813d1 131
PixArtVY 1:469063631a05 132 if(mode == 0 && imageQuality_total < laser2LED_threshold) //Check the condition for when we need to change to LED.
PixArtVY 0:2c144b6813d1 133 {
PixArtVY 1:469063631a05 134 load(modeLED, modeLED_size); //Loads the register array that has the settings for LED mode.
PixArtVY 1:469063631a05 135 mode = 1; //Sets the mode-tracker to be 1 to reflect LED mode.
PixArtVY 1:469063631a05 136 LDP = 1; //Sets the laser diode GPIO pin to be HIGH (inactive because of PMOS pull-up).
PixArtVY 1:469063631a05 137 wait_ms(40); //Delay for timing.
PixArtVY 1:469063631a05 138 writeRegister(0x03, 0x00); //Unlisted...
PixArtVY 0:2c144b6813d1 139
PixArtVY 1:469063631a05 140 //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
PixArtVY 1:469063631a05 141 //pc.printf("Now in LED mode. Value of 'mode': %1X\n\r", mode);
PixArtVY 1:469063631a05 142 //Uncomment these lines and the other print lines above for debugging. Prints image quality and tracks mode-switches.
PixArtVY 0:2c144b6813d1 143 }
PixArtVY 0:2c144b6813d1 144 }
PixArtVY 0:2c144b6813d1 145
PixArtVY 0:2c144b6813d1 146 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 147 }
PixArtVY 0:2c144b6813d1 148
PixArtVY 0:2c144b6813d1 149
PixArtVY 0:2c144b6813d1 150 //=========================================================================
PixArtVY 0:2c144b6813d1 151 void grabData(void)
PixArtVY 0:2c144b6813d1 152 {
PixArtVY 0:2c144b6813d1 153 int16_t deltaX_high, deltaX_low = 0; //These four variables store the low/high bits of the deltaX and deltaY data.
PixArtVY 0:2c144b6813d1 154 int16_t deltaY_high, deltaY_low = 0;
PixArtVY 0:2c144b6813d1 155
PixArtVY 0:2c144b6813d1 156 deltaX_low = (int16_t)readRegister(0x03); //Grabbing the data from registers.
PixArtVY 0:2c144b6813d1 157 deltaY_low = (int16_t)readRegister(0x04);
PixArtVY 0:2c144b6813d1 158 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 159 deltaY_high = ((int16_t)readRegister(0x12))<<8;
PixArtVY 0:2c144b6813d1 160
PixArtVY 0:2c144b6813d1 161 deltaX = deltaX_high | deltaX_low; //Combines the low/high bits of X and Y to be one variable.
PixArtVY 0:2c144b6813d1 162 deltaY = deltaY_high | deltaY_low;
PixArtVY 0:2c144b6813d1 163 }
PixArtVY 0:2c144b6813d1 164
PixArtVY 0:2c144b6813d1 165
PixArtVY 0:2c144b6813d1 166 //=========================================================================
PixArtVY 0:2c144b6813d1 167 void printData(void)
PixArtVY 0:2c144b6813d1 168 {
PixArtVY 0:2c144b6813d1 169 if((deltaX != 0) || (deltaY != 0)) //If there is deltaX or deltaY movement, print the data.
PixArtVY 0:2c144b6813d1 170 {
PixArtVY 1:469063631a05 171 totalX += deltaX;
PixArtVY 1:469063631a05 172 totalY += deltaY;
PixArtVY 1:469063631a05 173
PixArtVY 1:469063631a05 174 pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY); //Prints each individual count of deltaX and deltaY.
PixArtVY 1:469063631a05 175 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 176 }
PixArtVY 0:2c144b6813d1 177
PixArtVY 0:2c144b6813d1 178 deltaX = 0; //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
PixArtVY 0:2c144b6813d1 179 deltaY = 0;
PixArtVY 0:2c144b6813d1 180 }