bug fix for the power-supply firmware

[digitaldcpower] / analog.c

diff --git a/analog.c b/analog.c
index 6c4b3d8..1aff565 100644 (file)
--- a/analog.c
+++ b/analog.c
@@ -101,9 +101,10 @@ int16_t getanalogresult(uint8_t channel)
 // the control loop changes the dac:
 static void control_loop(void){
        int16_t tmp;
-       int8_t ptmp=0;
        tmp=target_val[0] - analog_result[0]; // current diff
        if (tmp <0){
+               // ** current control:
+               //
                // stay in currnet control if we are
                // close to the target. We never regulate
                // the difference down to zero otherweise
@@ -111,56 +112,39 @@ static void control_loop(void){
                // and then back to current control. Permanent
                // hopping would lead to oscillation and current
                // spikes.
-               if (tmp>-4) tmp=0;
-               currentcontrol=40; // I control
+               if (tmp>-2) tmp=0;
+               currentcontrol=10; // I control
                if (analog_result[1]>target_val[1]){
+                       // oh, voltage too high, get out of current control:
                        tmp=-20;
                        currentcontrol=0; // U control
                }
        }else{
+               // ** voltage control:
+               //
                // if we are in current control then we can only go
                // down (tmp is negative). To increase the current
                // we come here to voltage control. We must slowly
                // count up.
-               tmp=1 + target_val[1]  - analog_result[1]; // voltage diff
-               //
+               tmp=1+ target_val[1]  - analog_result[1]; // voltage diff
                if (currentcontrol){
                        currentcontrol--;
-                       if (currentcontrol%8==0){
-                               // slowly up, 20 will become 1 further down
-                               if (tmp>0) tmp=20;
-                       }else{
-                               tmp=0;
-                       }
+                       // do not go up immediately after we came out of current control:
+                       if (tmp>0) tmp=0;
                }
        }
-       if (tmp==0){
-               return; // nothing to change
-       }
-       if (tmp> -5 && tmp<5){ // avoid LSB bouncing if we are close
-               if (tmp>0){
-                       ptmp++;
-                       tmp=0;
-                       if (ptmp>1){
-                               tmp=1;
-                               ptmp=0;
-                       }
-               }
-               if (tmp<0){
-                       ptmp--;
-                       tmp=0;
-                       if (ptmp<-1){
-                               tmp=-1;
-                               ptmp=0;
-                       }
-               }
+       if (tmp> -3 && tmp<4){ // avoid LSB bouncing if we are close
+               tmp=0;
        }
+       if (tmp==0) return; // nothing to change
        // put a cap on increase
        if (tmp>1){
                tmp=1;
        }
        // put a cap on decrease
-       if (tmp<-1){
+       if (tmp<-200){
+               tmp=-20;
+       }else if (tmp<-1){
                tmp=-1;
        }
        dac_val+=tmp;