[Solved]Driving a single servo

JimW

using the M5 with firmware 1.2.3en and arduino 1.8.9

I know you can't use servo.h, so I came up with a work around, or at least I thought I did.

I cannot have M5.begin(); in the code or the servo doesn't work, without that the servo works but I cannot write to display.
Is there a solution? here's the example code;

#include <M5Stack.h>

#define servoPin 5
int i = 0;
int servoPulse(int angle) {
int pulseWidth = map(angle, 0, 180, 544, 2400);
return pulseWidth;
}

void setup() {

m5.begin();
Serial.begin(9600);
pinMode(servoPin, OUTPUT);

}

void loop() {

for (int i=0; i<=180; i++) { // drive servo from 0 to 180 at max response
int pulseWidth = servoPulse(i);
//digitalWrite(servoPin, HIGH);
delayMicroseconds(pulseWidth);
//digitalWrite(servoPin, LOW);
delayMicroseconds(20000 - pulseWidth);
Serial.print(i);
}

for (int i=180; i>=0; i--) { // return to 0 at half speed
int pulseWidth = servoPulse(i);
//digitalWrite(servoPin, HIGH);
delayMicroseconds(pulseWidth);
//digitalWrite(servoPin, LOW);
// delayMicroseconds(20000 - pulseWidth);
delay(50);
Serial.print(i);
}

}

salty_good

Hi, Please try to comment out this line -> Serial.begin(9600);

Thank you!

salty_good

(Already set to serial speed 115200 in M5.begin () function)

JimW

I was hoping that it would be that simple, however, that wasn't the solution.

I cannot use M5.Lcd.print and the servo at the same time.

ajb2k3

What device are you using?
I use G21 which is also SDA on port A

JimW

I'm using an M5stack Core with the accelerometer built in, and arduino 1.8.9

This problem occurs when using M5.begin(); which I apparently need to print to lcd inside the loop.

So for instance, inside the loop,

M5.Lcd.setCursor(0, 200);
M5.lcd.setTextColor(WHITE,BLACK);
M5.Lcd.print (i);

The Servo will not work, but instead chatter.
// M5.begin(); servo works but the display does not (this statement is inside the setup, for example,

void setup() {

M5.begin();

//myservo.attach(servoPin);

}

salty_good

@jimw Please try this code.
Serial speed 115200

and the firmware (1.2.3-en) for micropython
It is not for Arduino.

#include <M5Stack.h>

int servoPin = 5;

void servoSet(int Angle, int Time) {
  int pulseWidth;
  int TimeCount;

  TimeCount = Time / 20;

  for (int i = 0; i <= TimeCount; i++) {
    pulseWidth = map(Angle, 0, 180, 544, 2400);
    digitalWrite(servoPin, HIGH);
    delayMicroseconds(pulseWidth);
    digitalWrite(servoPin, LOW);
    delayMicroseconds(20000 - pulseWidth);
  }
}

void setup() {
  M5.begin();
  M5.Lcd.printf("M5Stack Servo test:\n");
  pinMode(servoPin, OUTPUT);
}

void loop() {
  M5.Lcd.printf("Angle 45deg\n");
  Serial.println("Angle 45deg");
  servoSet(45, 1000); //45deg
  M5.Lcd.printf("Angle 135deg\n");
  Serial.println("Angle 135deg");
  servoSet(135, 1000); //135deg
}