laurb9
commented
3 years ago Interesting, thank you for the detailed report and the code samples. The library outputs the exact number of steps with move() so there should be no drift in pulses.
I will try to replicate this. Until then, a possible explanation is the momentum of the motor pushes it one more step after the end, or the RPM is high enough that the motor misses steps at startup. Testing with a very low RPM and without load should show if this is the case. I see the test code uses a 400 step motor with 4 and 2ms steps, so it rotates at 37rpm and 75rpm, while the library is set at 100rpm.
A current setting that is lower than what the motor needs may also cause slippage, as it gives the motor less torque. I am not familiar with the TB6600 but it should have a way to set this.
Finally, the step impulse emitted by the library may be too short for the TB6600. The test code uses a 50% duty cycle so that's a very comfortable duration, but the BasicStepperDriver uses 1µs pulses. Will need to check the sheet for TB6600 to see what it needs. For example, DRV8834 needs 2µs and the library adjusted to that.
vaughanatworld
sajjsamm
stale[bot]
swappart
Describe the bug Turn the stepper 200 steps clockwise, then 200 steps counterclockwise. Repeat. After a minute or so one can see the shaft home position creeping in one direction. Same behavior found in AccelStepper library. A simple nonlibrary implementation of the test shows no creep even after an hour.
To Reproduce Steps to reproduce the behavior: This creeps. Doesn't matter if one uses degrees or steps: /*
include
include "BasicStepperDriver.h"
// Motor steps per revolution. Most steppers are 200 steps or 1.8 degrees/step
define MOTOR_STEPS 200
define RPM 100 //120
// Since microstepping is set externally, make sure this matches the selected mode // If it doesn't, the motor will move at a different RPM than chosen // 1=full step, 2=half step etc.
define MICROSTEPS 1
// All the wires needed for full functionality
define DIR 2
define STEP 3
//Uncomment line to use enable/disable functionality //#define SLEEP 13
// 2-wire basic config, microstepping is hardwired on the driver BasicStepperDriver stepper(MOTOR_STEPS, DIR, STEP);
//Uncomment line to use enable/disable functionality //BasicStepperDriver stepper(MOTOR_STEPS, DIR, STEP, SLEEP);
void setup() { stepper.begin(RPM, MICROSTEPS); // if using enable/disable on ENABLE pin (active LOW) instead of SLEEP uncomment next line // stepper.setEnableActiveState(LOW); }
void loop() {
}
Expected behavior This works:
include
/ Example sketch to control a stepper motor with TB6600 stepper motor driver and Arduino without a library: number of revolutions, speed and direction. More info: https://www.makerguides.com / // Define stepper motor connections and steps per revolution:
define dirPin 2
define stepPin 3
define stepsPerRevolution 400
void setup() { // Declare pins as output: pinMode(stepPin, OUTPUT); pinMode(dirPin, OUTPUT); }
void loop() { // Set the spinning direction clockwise: digitalWrite(dirPin, HIGH); delayMicroseconds(100); // Spin the stepper motor 1 revolution slowly: for (int i = 0; i < stepsPerRevolution; i++) { // These four lines result in 1 step: digitalWrite(stepPin, HIGH); delayMicroseconds(2000); digitalWrite(stepPin, LOW); delayMicroseconds(2000); } delay(1000); // Set the spinning direction counterclockwise: digitalWrite(dirPin, LOW); delayMicroseconds(100); // Spin the stepper motor 1 revolution quickly: for (int i = 0; i < stepsPerRevolution; i++) { // These four lines result in 1 step: digitalWrite(stepPin, HIGH); delayMicroseconds(1000); digitalWrite(stepPin, LOW); delayMicroseconds(1000); } delay(1000); }
Platform Setup (please complete the following information):
Additional context Add any other context about the problem here. If the library is supposed to only be used for speed control, this issue may not matter. If the library is supposed to support position control, then this is a problem.