Diff: main.cpp

Revision:

2:1b142e2aa23e

Parent:

1:2d9d931c8484

Child:

3:a8ec3c6aeb08

--- a/main.cpp	Mon Jan 09 14:35:41 2017 +0000
+++ b/main.cpp	Fri Jan 13 14:41:31 2017 +0000
@@ -7,7 +7,9 @@
 const uint8_t ALSDataRegister = 0x14;
 const uint8_t waitIntervals = 100; //number of 2.73 ms waits
 const int measPeriod_ms = 699;
-
+const float tempRef = 29.5;  //C temperature at which all optical powers are calculated to
+const float Ch0tempCo = 0.0025; // % per degree C
+const float warmUp = 15; //number of measurements with a higher than usual pGain (to get to target faster);
 
 I2C i2c(I2C_SDA,I2C_SCL);
 Serial pc(USBTX,USBRX); //open serial port (optionally add baud rate after specifying TX and RX pins)
@@ -109,26 +111,36 @@
     writeRegister(TMD2772_Addr,(0x0F | 0x80),0x00); //ALS gain is 1x
 }
 
+float tempCorrectTMDCh0(float counts, float tempC) 
+{
+    float tDiff = tempC-tempRef;
+    float delta = Ch0tempCo*tDiff; //the % difference observed vs. reference temperature
+   return counts *(1-delta); //the count value equivalent if measured at reference temperature (less counts if temp is higher)
+    
+}
+
+
 int main() {
     float ratio;
     char data[4];
     uint16_t ch0Data;
     uint16_t ch1Data;
-    float setpoint = 2.1148; //ch0/ch1 color setpoint ~0.88 duty cycle
-    float step; //duty cycle change per sample
-    float dutyCycle=0.926;
+    float setpoint = 37250; //ch0/ch1 color setpoint ~0.88 duty cycle
+    static float step; //duty cycle change per sample
+    float dutyCycle=0.9275;
     float dutyCycleMin =0.8;
-    float dutyCycleMax =0.99;
+    float dutyCycleMax =0.98;
     float stepMax=0.0025;
     float stepMin=-0.0025;
 //    float iGain = 0.05; //integral gain --adding this because when I blew on it, it couldn't recover
     float err;
-    float tol=1e-4; //tolerance within which to ignore changes in signal intensity
-    float pGain = 0.2; //proportional gain
-    float quadGain = 0; // 250 : 0.2 ratio relative to pGain
+    float tol=1; //tolerance within which to ignore changes in signal intensity
+    float pGain = 0.25; //proportional gain
+//    float quadGain = 0;*/
+    static float temperature = 0;
     //float ch0Avg; //integral error
 //    float filterLength = 15;
-  
+    float tempFilterLength = 8;
     //setup everything
     mypwm.period_us(400);
     mypwm.write(dutyCycle);
@@ -138,6 +150,7 @@
     regDump(TMD2772_Addr,(0x00 | 0x80),0x0F);
     pc.printf("Done initializing\r\n");
     wait_ms(700);
+    static int loopCount =0;
     
     //get initial filter value
 //    reg2write=ALSDataRegister | 0x80;
@@ -152,6 +165,15 @@
     
     
     while(1) {
+        loopCount++;
+        if (loopCount<warmUp) 
+        {
+            pGain =0.25;
+        }
+        else 
+        {
+            pGain =0.2;
+        }
         t.start();
         readRegisters(TMD2772_Addr, (ALSDataRegister | 0x80), data ,4);
         //reg2write=ALSDataRegister | 0x80;
@@ -159,15 +181,24 @@
 //        i2c.write(TMD2772_Addr,&reg2write,1,true); //1 byte of data, repeated start for read
 //        i2c.read(TMD2772_Addr,data,4);
         ch0Data = LSB_MSB_2uint16(data);
+        if (temperature ==0) 
+        {
+            temperature = getTemp(MAX31725_Addr);
+        }
+        else 
+        {
+            temperature += (getTemp(MAX31725_Addr)-temperature)/tempFilterLength  ;  
+        }
+        ch0Data = tempCorrectTMDCh0(ch0Data,temperature);
         ch1Data = LSB_MSB_2uint16(data+2);
         ratio = (float)ch0Data/(float)ch1Data;
-        err = ratio - setpoint;
-        pc.printf( "%U,%U, %f, %f, %f\r\n",ch0Data,ch1Data,ratio,mypwm.read(),getTemp(MAX31725_Addr) );
+        err = ch0Data - setpoint;
+        pc.printf( "%U,%U, %f, %f, %f, %f\r\n",ch0Data,ch1Data,ratio,mypwm.read(),temperature, step);
         if (abs(err)>tol) {
-            step = err * pGain + err/abs(err)*pow(err,2)*quadGain;
+            step = err/setpoint * pGain ;
             step = (step > stepMax) ? stepMax : step;
             step = (step < stepMin) ? stepMin : step;
-            dutyCycle -=step;
+            dutyCycle -= step;
             dutyCycle = (dutyCycle < dutyCycleMin) ? dutyCycleMin : dutyCycle;
             dutyCycle = (dutyCycle > dutyCycleMax) ? dutyCycleMax : dutyCycle;
             //update with new settings