diff --git a/src/pid.c b/src/pid.c --- a/src/pid.c +++ b/src/pid.c @@ -20,38 +20,39 @@ void pid_init() float pid_process(void) { + // #ifdef MAX31865_RTD_SENSOR // max31865_readtemp(spi_get(), &set, &status); // #else // max31855_readtemp(spi_get(), &set, &status); // Read MAX31855 // #endif - float ssr_output = 0; + float ssr_output = 0; - if(runtime_status()->pid_enabled) - { - // Get ssr output for next time - int16_t power_percent = pid_update(); + if(runtime_status()->pid_enabled) + { + // Get ssr output for next time + int16_t power_percent = pid_update(); - if(flash_getsettings()->val.plant_type == PLANT_HEATER) - power_percent *= -1; + if(flash_getsettings()->val.plant_type == PLANT_HEATER) + power_percent *= -1; - //power-percent is 0-1000? - ssr_output = power_percent; //(((uint32_t)SSR_PERIOD * (uint32_t)10 * (uint32_t)100) * power_percent) / (uint32_t)1000000; + //power-percent is 0-1000? + ssr_output = power_percent; //(((uint32_t)SSR_PERIOD * (uint32_t)10 * (uint32_t)100) * power_percent) / (uint32_t)1000000; - // put ssr output on display - ssd1306_drawstring(" ", 0, 90); //fixme: this is bad, but I can't get the old digits to clear otherwise - char tempstr[6]; - itoa(ssr_output, tempstr, 10); - ssd1306_drawstring(tempstr, 0, 90); - } - else - { - ssr_output = 0.0; - } + // put ssr output on display + ssd1306_drawstring(" ", 0, 90); //fixme: this is bad, but I can't get the old digits to clear otherwise + char tempstr[6]; + itoa(ssr_output, tempstr, 10); + ssd1306_drawstring(tempstr, 0, 90); + } + else + { + ssr_output = 0.0; + } - return ssr_output; + return ssr_output; } int16_t pid_update(void) @@ -59,50 +60,50 @@ int16_t pid_update(void) therm_status_t* status = runtime_status(); therm_settings_t* set = flash_getsettings(); - // Convert temperature to fixed point number with 1/10th resolution - float temp = status->temp; + // Convert temperature to fixed point number with 1/10th resolution + float temp = status->temp; - // Calculate instantaneous error - int16_t error = status->setpoint * 10 - temp; // TODO: Use fixed point fraction + // Calculate instantaneous error + int16_t error = status->setpoint * 10 - temp; // TODO: Use fixed point fraction - // Proportional component - int32_t p_term = set->val.k_p * error; + // Proportional component + int32_t p_term = set->val.k_p * error; - // Error accumulator (integrator) - state.i_state += error; + // Error accumulator (integrator) + state.i_state += error; - // to prevent the iTerm getting huge from lots of - // error, we use a "windup guard" - // (this happens when the machine is first turned on and - // it cant help be cold despite its best efforts) - // not necessary, but this makes windup guard values - // relative to the current iGain - int32_t windup_guard_res = (set->val.windup_guard * 10) / set->val.k_i; + // to prevent the iTerm getting huge from lots of + // error, we use a "windup guard" + // (this happens when the machine is first turned on and + // it cant help be cold despite its best efforts) + // not necessary, but this makes windup guard values + // relative to the current iGain + int32_t windup_guard_res = (set->val.windup_guard * 10) / set->val.k_i; - // Calculate integral term with windup guard - if (state.i_state > windup_guard_res) + // Calculate integral term with windup guard + if (state.i_state > windup_guard_res) state.i_state = windup_guard_res; - else if (state.i_state < -windup_guard_res) + else if (state.i_state < -windup_guard_res) state.i_state = -windup_guard_res; - int32_t i_term = set->val.k_i * state.i_state; + int32_t i_term = set->val.k_i * state.i_state; - // Calculate differential term (slope since last iteration) - int32_t d_term = (set->val.k_d * (temp - state.last_pid_temp)); + // Calculate differential term (slope since last iteration) + int32_t d_term = (set->val.k_d * (temp - state.last_pid_temp)); - // Save temperature for next iteration - state.last_pid_temp = temp; + // Save temperature for next iteration + state.last_pid_temp = temp; - int16_t result = (p_term + i_term - d_term) / 10; + int16_t result = (p_term + i_term - d_term) / 10; - // Put out tenths of percent, 0-1000. - if(result > 1000) - result = 1000; - else if(result < -1000) - result = -1000; + // Put out tenths of percent, 0-1000. + if(result > 1000) + result = 1000; + else if(result < -1000) + result = -1000; - // Return feedback - return result; + // Return feedback + return result; }