Diff: commHeaders/SPIcommFunctions.h

Revision:

0:2c144b6813d1

Child:

1:469063631a05

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/commHeaders/SPIcommFunctions.h	Mon Mar 19 21:18:40 2018 +0000
@@ -0,0 +1,195 @@
+//=========================================================================
+//Communication pinouts for serial COM port, SPI, and interrupts
+//=========================================================================
+static Serial pc(USBTX, USBRX);                     //PC serial communication.
+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).
+static DigitalOut cs(p22);                          //Chip select pin.
+static DigitalOut LDP(p20);                         //Laser diode pin.
+
+
+//=========================================================================
+//Variables and arrays used for communications and data storage
+//=========================================================================
+int16_t deltaX = 0;                                 //Stores X-axis output data.
+int16_t deltaY = 0;                                 //Stores Y-axis output data.
+
+uint8_t frameCounter = 0;                           //Looping variable to track when we have grabbed 8 frames of data.
+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).
+uint16_t imageQuality_total = 0;                    //Stores the sum of all raw values from the 8 frames from imageQuality[8].
+uint8_t imageQualityOK = 0;
+uint8_t mode = 0;                                   //Modes: 0 = Laser, 1 = LED.    Laser is default.
+#define laser2LED_threshold 0x700                   //Stores threshold level for when we need to swap to LED mode.
+#define LED2laser_threshold 0x500                   //Stores threshold level for when we need to swap to laser mode.
+
+uint8_t currentBank;                                //Stores current register bank.
+
+
+//=========================================================================
+//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 checkMode(void);
+//This function checks the image quality of each frame and switches between LED and laser modes when necessary.
+
+void grabData(void);
+//Takes data from the sensor and stores it into variables deltaX and deltaY.
+
+void printData(void);
+//Prints the deltaX and deltaY values to a serial terminal whenever the values change.
+
+
+
+
+
+//=========================================================================
+//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_ms(1);
+    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
+    
+    if(addr == 0x7F)                //You can't read register 0x7F for the current bank so we store the value before writing it
+    {
+        currentBank = data;         //Store the current bank for printing later.
+        //pc.printf("B:%2X, R:%2X, D:%2X\n\r", currentBank, (addr & 0x7F), currentBank);
+            //Uncomment this line and the other print line below for debugging. Prints every register bank change.
+    }
+    
+    else
+    {
+        //pc.printf("B:%2X, R:%2X, D:%2X\n\r", currentBank, (addr & 0x7F), readRegister(addr));
+            //Uncomment this line and the other print line above for debugging. Prints every register write operation.
+    }
+    
+    wait_ms(2);
+}
+
+
+//=========================================================================
+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 checkMode(void)
+{
+    uint16_t data_msb, data_lsb = 0;                 //These variables store the high and low bits of image quality data.
+    imageQuality_total = 0;                         //This variable holds the sum of 8 frames of data.
+    
+    data_msb = readRegister(0x75);                  //Reads upper 8 bits of image quality.
+    data_lsb = readRegister(0x76);                  //Reads lower 8 bits of image quality.
+    imageQuality[frameCounter] = data_msb*256 + data_lsb;   //Combines the low/high bits to be a single element in this array.
+    
+    if(frameCounter == 7)                           //We check image quality every EIGHT samples before determining if a mode-switch is necessary.
+    {
+        for(int i=0; i<8; i++)                      //Sums up 8 frames of image quality data into 1 variable.
+        {
+            imageQuality_total = imageQuality_total + imageQuality[i];
+        }
+        
+        if(imageQualityOK == 0 && imageQuality_total > LED2laser_threshold) //If imageQuality is over 0x500, we can continue to select the proper mode.
+        {
+            imageQualityOK = 1;
+            
+        }
+        
+        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.
+        {
+            imageQualityOK = 0;
+            pc.printf("Image quality too low! Value: %4X\n\r", imageQuality_total);
+        }
+        
+        
+        if(imageQualityOK)
+        {
+            pc.printf("Image quality OK! Value: %4X\n\r", imageQuality_total);
+            
+            if(mode == 1 && imageQuality_total < LED2laser_threshold)       //Check the condition for when we need to change to laser.
+            {
+                load(modeLaser, modeLaser_size);        //Loads the register array that has the settings for laser mode.
+                mode = 0;                               //Sets the mode-tracker to be 0 to reflect laser mode.
+                LDP = 0;                                //Sets the laser diode GPIO pin to be LOW (active because of PMOS pull-up).
+                wait_ms(40);                            //Delay for timing.
+                writeRegister(0x03, 0x00);              //Delta_XL?????? TRY TO FIND OUT WHAT THIS REGISTER IS FOR**********************************************************
+                
+                //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
+                //pc.printf("Now in laser mode. Value of 'mode': %1X\n\r", mode);
+                //Uncomment these lines and the other print lines below for debugging. Prints image quality and tracks mode-switches.
+            }
+            
+            if(mode == 0 && imageQuality_total < laser2LED_threshold)  //Check the condition for when we need to change to LED.
+            {
+                load(modeLED, modeLED_size);            //Loads the register array that has the settings for LED mode.
+                mode = 1;                               //Sets the mode-tracker to be 1 to reflect LED mode.
+                LDP = 1;                                //Sets the laser diode GPIO pin to be HIGH (inactive because of PMOS pull-up).
+                wait_ms(40);                            //Delay for timing.
+                writeRegister(0x03, 0x00);              //Delta_XL?????? TRY TO FIND OUT WHAT THIS REGISTER IS FOR**********************************************************
+                
+                //pc.printf("Image Quality: %4X\n\r", imageQuality_total);
+                //pc.printf("Now in LED mode. Value of 'mode': %1X\n\r", mode);
+                //Uncomment these lines and the other print lines above for debugging. Prints image quality and tracks mode-switches.
+            }
+        }
+    }
+    
+    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.
+}
+
+
+//=========================================================================
+void grabData(void)
+{
+    int16_t deltaX_high, deltaX_low = 0;            //These four variables store the low/high bits of the deltaX and deltaY data.
+    int16_t deltaY_high, deltaY_low = 0;
+    
+    deltaX_low = (int16_t)readRegister(0x03);       //Grabbing the data from registers.
+    deltaY_low = (int16_t)readRegister(0x04);
+    deltaX_high = ((int16_t)readRegister(0x11))<<8; //Shifts high bits left by 8 so that we can combine high and low bytes together.
+    deltaY_high = ((int16_t)readRegister(0x12))<<8;
+    
+    deltaX = deltaX_high | deltaX_low;              //Combines the low/high bits of X and Y to be one variable.
+    deltaY = deltaY_high | deltaY_low;
+}
+
+
+//=========================================================================
+void printData(void)
+{
+    if((deltaX != 0) || (deltaY != 0))      //If there is deltaX or deltaY movement, print the data.
+    {
+        pc.printf("deltaX: %d\t\t\tdeltaY: %d\n\r", deltaX, deltaY);
+    }
+    
+    deltaX = 0;                             //Resets deltaX and Y values to zero, otherwise previous data is stored until overwritten.
+    deltaY = 0;
+}