NodeMCU and DRV8825

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.

This list is made with only mentioning how it handles digital logic and interrupts

DRV8825: https://www.pololu.com/product/2133

Limit switch:

This means that we need 8 outputs that doesn't have fixed pullups and can handle boot with pulldowns on the pins. And 2 interrupt inputs with at least one that has a pullup.

As seen in the list below this means that D3 and D4 need to be inputs and one of the serial lines as output.

NodeMCU v1.0 Amica ESP-12E: