madhephaestus
commented
2 years ago can you verify the blip never fires with a scope? Also its a tight timing for a hobby servo, depending on the time in the cycle of the PWM cycle you could be in between the pulses when you set the new PWM. New values arent loaded until the next cycle, so that can be 30 ms away. You might be asking the servo to respond without enough control pulses? How many pulses does your servo need before it passes the runt rejection? (that will be a per servo difference) For an application this tight riming you might want to look into a 333 or 300 hz servo, they can be driven much faster than standard hobby servos, but are a bit more rare.
Alex-Scheff
I'm working on an engine controller. A servo controls the throttle plate. It works pretty well with only one exception: Sometimes when doing a ''blip'' (opening up the plate for 100ms) it just won't do it. It's random, sometimes it works, sometimes it doesn't. A workaround for that is to detach and immediately reattach the servo before doing the blip. Do you have an idea why it might do that?
The servo related code snippets: `// Servo Init
ESP32PWM::allocateTimer(0); ESP32PWM::allocateTimer(1); ESP32PWM::allocateTimer(2); ESP32PWM::allocateTimer(3); throttleServo.setPeriodHertz(330); if(throttleServo.attach(servoPinThrottle, 900, 2100)){ Serial.println("ThrottleServo attached successfully"); } else { Serial.println("No connection to ThrottleServo, this is BAD"); Serial.println("Engine can't start, ignition is cut!"); digitalWrite(ignitionCutRelaisPin, HIGH); Serial.println("Infinite loop starting now..."); for(;;); } throttleServo.write(servoMinDegree); delay(5);`
`void handleThrottleServo(){ // Get's called every time in Loop
switch(throttleMode){ case 1: // Low Power Linear Mode servoMapOben = servoMaxDegree + 40; break; case 2: // Mid Power Linear Mode servoMapOben = servoMaxDegree + 20; break; case 3: // High Power Linear Mode servoMapOben = servoMaxDegree; break; } if(waterTempAfterIntercooler < coolantTempSetValue){ // Wenn Kühlmitteltemperatur unter 30 Grad Leerlaufdrehzahl erhöhen servoMapUnten = servoMinDegree - 15; // Muss später getestet werden und eventuell etwas höher gesetzt werden } else { servoMapUnten = servoMinDegree; } servoDegree = map(smoothedPotValue, linearPotLowValue, linearPotHighValue, servoMapUnten, servoMapOben); if(launchControlActive){ int8_t rpmDif = drehzahlSpeedRaw - drehzahlFront; // Die zwei werden nie genau gleich sein, ein Fehlerbereich muss vernachlässigt werden dürfen. Wie hoch? Die 0 muss später angepasst werden. Lenkwinkel notwendig? if(rpmDif > 10){ // Wenn rpmDif größer Null ist dann dreht die Hinterachse durch lcVal--; } else if(rpmDif <= -11){ lcVal = 0; } servoDegree =+ lcVal; } throttleServo.write(servoDegree); }`
`void throttleBlipFunction(){ // Get's called every time I'm trying to downshift
if(!throttleBlipActive){ throttleServo.detach(); throttleServo.attach(servoPinThrottle, 900, 2100); throttleServo.write(servoMaxDegree); //Serial.println("Throttle Blip aktiv"); switch(gear){ // Zeiten später nach Tests anpassen case 2: timeDelayThrottleBlip = 200; break; case 3: timeDelayThrottleBlip = 180; break; case 4: timeDelayThrottleBlip = 160; break; case 5: timeDelayThrottleBlip = 140; break; case 6: timeDelayThrottleBlip = 120; break; } startTimeThrottleBlip = millis(); throttleBlipActive = true; } else if(millis() >= startTimeThrottleBlip + timeDelayThrottleBlip){ throttleBlipActive = false; } }`