Controlling a Stepper - Timing issues?

Projects General Guidance
1

I know I shouldn't start a second thread for the same question, so I hope it's ok that I'm just asking a question here that we can't get resolved in the other thread. - If that's not ok, I ask a moderator to delete the thread here.

Why does the engine behave the way it behaves? - Why does the motor twitch when the stick input goes to the left?

Post

I would be grateful for an explanation.

Matt_Hias

2

Schematics and code please.

3

That is all controlled by the program you wrote. Now you need to debug your program, step by step. Best to begin with the "stick".

4

Schematics: servo-schema.pdf (17.8 KB)

Code: PWM zu Step-Dir - Ich komme nicht weiter - #77 by kolaha

5

what is that strange circuit?

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does your driver need of discrete pulse wires? why you does not mentioned it?
yes it is, separated wires.
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it can be reason why one way it run smooth, other way motor jitters

6

Here is Code: PWM zu Step-Dir - Ich komme nicht weiter - #77 by kolaha

i am sorry, there was a line missing.
servo-schemaV1.1.pdf (18.0 KB)

7

Do you really have a +12V and -12V line but no GND anywhere but USB?

You code: are you sure you read the PWM signal without jitter?

8

That looks okey but the anonymous 5/12 converter as well as driver are unknown devices.
Are You still updating the post? It looks like ghosts are flying in.

9

The 5/12 Konverter is a Mauch Power Cube V3

Link

The powersource ist a 6S lipo battery. The Voltage should be high enough for mauch as well as the motor.

The 12V are powering the herelink-airunit.

10

I do not understand what U are meaning. With that ?

With the Jitter: I am not sure how tho check this, Serial slows it to much down.

If i check it with serial, not Jitter is visible but motor runs only a fraction of his speed.

11

Maybe, i have to close the browser in my phone?

12

Please add new information in new replies. Updating old replies makes the conversation disturbed for new readers.

13

loop(): du blockierst Interrupts und erlaubst sie dann wieder --> deine Messung der Pulsbreite ist zufällig.

14

I think it's easy to fix.

15

What is your proposal?

16

no, the issue is something other. i thought i just add a max function to be sure that length of high impulse not exceed the length of period, but now i remember the code already contain such check

if (!(pulse_Lenght > 1000 && pulse_Lenght < 2000))pulse_Lenght = 0;
...
if (pulse_Lenght)temp = pulse_Lenght - Mitte;
17

ok, just to be sure:

#define PWM_Pin 2
#define DIR 4
#define STEP 5

volatile  uint32_t lastPulseTime = 0;
volatile  uint32_t pulse_Lenght = 0;
volatile  uint32_t PulseTime = 0;

void setup() {
  //  Serial.begin(250000);
  attachInterrupt(digitalPinToInterrupt(PWM_Pin), Pulse, CHANGE);
  pinMode(DIR , OUTPUT);
  pinMode(STEP , OUTPUT);
}

void Pulse() {
  if (digitalRead(PWM_Pin))lastPulseTime = micros();
  else {
    PulseTime = micros();
    pulse_Lenght = PulseTime - lastPulseTime;
    if (!(pulse_Lenght > 1000 && pulse_Lenght < 2000))pulse_Lenght = 0;
  }
}

void loop() {
  const int Mitte = 1500;
  static int channelValue = 0;
  static unsigned long previousMotorTime = 0;
  static unsigned long MotorInterval = 0xFFFFFFFF;
  static long temp = Mitte;
  //Serial.print("channelValue");
  //Serial.println(channelValue);
  //Serial.print("MotorInterval ");
  noInterrupts();
  if (pulse_Lenght)temp = (temp + pulse_Lenght - Mitte) / 2;
  delay(2);
  interrupts();
  //  Serial.print(" ");
  //  Serial.print(pulse_Lenght);
  //   Serial.print(" ");
  // Serial.print(temp);

  digitalWrite(DIR, temp >= 0);
  channelValue = constrain(abs(int(temp)), 0, 400);
  //  Serial.print(" ");
  //  Serial.print(channelValue);

  if (channelValue > 5)MotorInterval = (405 - channelValue) * 5;
  else MotorInterval = 0x0FFFFFFF;
  //  Serial.print(" ");
  //  Serial.println(MotorInterval);
  if (micros() - previousMotorTime >= MotorInterval) {
    digitalWrite(STEP, !digitalRead(STEP));
    previousMotorTime += MotorInterval;
  }
  //  delay(10);
}
18

Sorry, but there is no change at the Output.

I checked it with this code,
Post#77
there is change at the output.

19

If i out-comment the

the Code works. It runs smother than the code from Post#77 but has still the same issue.

20

Can U please point it out how U would solve the issue? Danke! :slight_smile: