pwmled: regulation using sum of differences

diff --git a/firmware/pwmled.c b/firmware/pwmled.c
index 90eb87017a2bee065244a665eeb8f7d95cd15ecc..b76f219fb32b1c597358832f333be26c621d50f4 100644 (file)
--- a/firmware/pwmled.c
+++ b/firmware/pwmled.c
@@ -61,6 +61,7 @@ static unsigned char pwmled_mode[N_PWMLEDS];
 static unsigned char pwmled_mode_set[N_PWMLEDS];
 
 static uint16_t pwm_probes[N_PWMLEDS];
+static int16_t differences[N_PWMLEDS];
 
 static void start_probing(unsigned char n)
 {
@@ -80,6 +81,7 @@ void pwmled_init()
        }
 
        for (i = 0; i < N_PWMLEDS; i++) {
+               differences[i] = 0;
                start_probing(i);
        }
 }
@@ -112,14 +114,7 @@ void pwmled_set_mode(unsigned char n, unsigned char mode)
        log_byte(n);
        log_byte(mode);
 #endif
-
-       if (mode == 0) {
-               pwm_off(n);
-               pwmled_state[n] = ST_OFF;
-               return;
-       }
-
-       if (mode <= N_PWMLED_MODES) {
+       if (mode > 0 && mode <= N_PWMLED_MODES) {
                uint16_t pwmval;
                mode--;
                pwmval = pwm_vals[n*N_PWMLED_MODES+mode];
@@ -130,6 +125,10 @@ void pwmled_set_mode(unsigned char n, unsigned char mode)
                pwmled_state[n] = ST_ON;
                pwmled_mode[n] = mode;
                pwmled_mode_set[n] = 1;
+               differences[n] = 0;
+       } else {
+               pwm_off(n);
+               pwmled_state[n] = ST_OFF;
        }
 }
 
@@ -203,10 +202,10 @@ static void inline probing_adc(unsigned char n, uint16_t adcval)
 static void inline on_adc(unsigned char n, uint16_t adcval)
 {
        unsigned char mode = pwmled_mode[n];
-       uint16_t adc_exp     =  adc_vals[n*N_PWMLED_MODES+mode];
-       uint16_t *pwm_p      = &pwm_vals[n*N_PWMLED_MODES+mode];
-       uint16_t old_pwm     = *pwm_p;
-       uint16_t new_pwm = old_pwm;
+       uint16_t adc_exp   =  adc_vals[n*N_PWMLED_MODES+mode];
+       uint16_t *pwm_p    = &pwm_vals[n*N_PWMLED_MODES+mode];
+       int16_t old_pwm    = *pwm_p;
+       int16_t new_pwm    = old_pwm;
 
 #if 0
        log_byte(0xF5);
@@ -214,45 +213,56 @@ static void inline on_adc(unsigned char n, uint16_t adcval)
        log_word(adcval);
 #endif
 
+
        if (pwmled_mode_set[n]) { // ignore the first reading
                pwmled_mode_set[n] = 0;
                return;
        }
 
-       // FIXME: running average?
-       if (2*adcval > 5*adc_exp) { // >2.5x expected, lower significantly
-               new_pwm = 2*old_pwm/3;
-       } else if (3*adcval > 4*adc_exp) { // >1.33x expected, lower a bit
-               new_pwm = old_pwm - 1;
-       } else if (4*adcval < 3*adc_exp) { // 0.75x expected, raise a bit
-               new_pwm = old_pwm + 1;
-       }
+       differences[n] += adcval;
+       differences[n] -= adc_exp;
 
-       // FIXME: better disconnect detection
-       if (new_pwm > pwm_max[n]) { // FIXME: disconnected?
+       if (differences[n] > 16)
+               new_pwm -= 2;
+       else if (differences[n] > 4)
+               new_pwm--;
+       else if (differences[n] < -16)
+               new_pwm += 2;
+       else if (differences[n] < -4)
+               new_pwm++;
+       // new_pwm -= differences[n] >> 3;
+
+       if (new_pwm == old_pwm)
+               return;
+
+       differences[n] = 0;
+
+       if (new_pwm > (int16_t)pwm_max[n]) {
+               // FIXME: disconnected?
                new_pwm = pwm_max[n];
        }
-       if (new_pwm < 2) { // short-circuit?
-               new_pwm = 2;
+
+       if (new_pwm < 1) {
+               // FIXME: short-circuit?
+               new_pwm = 1;
        }
 
-       if (new_pwm != old_pwm) {
-               *pwm_p = new_pwm;
-               pwm_set(n, new_pwm);
-#if 0
-               log_byte(0xF9);
+       *pwm_p = new_pwm;
+       pwm_set(n, new_pwm);
+
+       if (jiffies > 500 && n == 1) {
+               log_byte(adcval & 0xFF);
                log_byte(new_pwm);
-#endif
        }
 }
 
 void pwmled_adc(unsigned char n, uint16_t adcval)
 {
        unsigned char i, probing;
+
        switch (pwmled_state[n]) {
        case ST_PROBING:
                probing_adc(n, adcval);
-
 #if 1
                probing = 0;
                for (i = 0; i < N_PWMLEDS; i++)