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Don't use TX and it's alive

A project log for NodeMCU and DRV8825

Connecting all control pins from DRV8825 to NodeMCU

Johan WestlundJohan Westlund 08/22/2018 at 18:140 Comments

So GPIO1 aka TX is used for some special boot mode so it can't be pulldowned: https://bbs.espressif.com/viewtopic.php?t=796

So I moved direction to gpio16 instead. Now I'm also getting a direction indicator on the NodeMCUs inbuilt LED that is connected to gpio16.

I also had problem with gpio15 not being pulldowned enough when connected to DRV8825. So for now I removed it and shorted sleep and reset together to be controlled by the same pin.

Found out that fault (that I pulled up) is connected to the sleep pin on the DRV8825. So have to remove it and see if it will work after.

Test code:

// Test sketch for drv8825 on NodeMCU v1.0

// pinout definition for generic ESP-12E
#define stepPin 3
#define directionPin 16
#define sleepPin 15
#define resetPin 13
#define m2_Pin 12
#define m1_Pin 14
#define m0_Pin 4
#define enablePin 5
#define faultPin 2
#define endswitchPin 0

#define MOTOR_STEPS 200

void setStepSize() { //Going to add more later
  // Full step
  digitalWrite(m0_Pin, LOW);
  digitalWrite(m1_Pin, LOW);
  digitalWrite(m2_Pin, LOW);
}

void setup() {

  // REMEMBER THAT YOU CAN'T USE SERIAL FROM THIS POINT
  // DRV8825 has inbuilt pulldown resistors for all input pins. No need to set it.
  pinMode(stepPin, OUTPUT);
  pinMode(directionPin, OUTPUT);
  pinMode(sleepPin, OUTPUT);
  pinMode(resetPin, OUTPUT);
  pinMode(m2_Pin, OUTPUT);
  pinMode(m1_Pin, OUTPUT);
  pinMode(m0_Pin, OUTPUT);  
  pinMode(enablePin, OUTPUT);

  setStepSize();
  digitalWrite(resetPin, HIGH);
  digitalWrite(sleepPin, HIGH);
  digitalWrite(enablePin, LOW);
  
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(directionPin, HIGH);
  for (int i = 0; i < MOTOR_STEPS; i++) {
    digitalWrite(stepPin, LOW);
    delay(10); //10 ms
    digitalWrite(stepPin, HIGH);
    delay(10); //10 ms
  }
  digitalWrite(directionPin, LOW);
  for (int i = 0; i < MOTOR_STEPS; i++) {
    digitalWrite(stepPin, LOW);
    delay(10); //10 ms
    digitalWrite(stepPin, HIGH);
    delay(10); //10 ms
  }
  delay(1000);
}

 After flashing the code the motor is spinning 360 degrees and back again, wait 1 s and repeat.

PROOF: https://www.facebook.com/beaverelectronics/videos/vb.161215301217651/242073909790273/?type=2&theater

Going to add WiFi control, add better motor control, fix the small issues and test sleep in next step.

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