Nano pwm pins output only after a pin is physically pulled

Other Hardware General Electronics
1

I am using nano and multiwii to build a quadcopter. When I tried to calibrate ESCs, there is no pwm output from the nano, and could not calibrate. The same code on uno had no problem. But when I pulled one pwm pin out and put it back, then the pwm pins would have output and calibrate the ESCs. After calibration, I tried to fly the copter (with nano, did not test uno), it did not start when I have the motor throttle up, ESCs just kept beeping. Thanks for any suggestion.

2

It sounds like there is a bad pin on your Nano. The pins do not pull out of the board. Post a picture and a simple schematic if you can.

3

I did not mean that I really yanked a pin out from the board, I had to disconnect a pwm output pin so they would have output.

4

Did you write the copter code yourself? otherwise maybe the PWM pin is used during startup to setup parameters if it is pulled low (or high).
Like putting a receiver in bind mode by connecting a jumper cable and then power up.

5

we are flyin in the dark here - can you provide a schematic please?

1 Like
6

I am not familiar with them windy things so please post links to technical information on all the hardware devices. Market places such as amazon and Aliexpress only provide mainly sales information.

7

I am posting the calibration code first, then a video clip of what's happening. Here is the code:
'''
/*ESC calibration sketch; author: ELECTRONOOBS */
#include <Servo.h>

#define MAX_SIGNAL 2000
#define MIN_SIGNAL 1000
#define MOTOR_PIN1 6
#define MOTOR_PIN2 5
#define MOTOR_PIN3 11
#define MOTOR_PIN4 3

int DELAY = 1000;

Servo motor1;
Servo motor2;
Servo motor3;
Servo motor4;

void setup() {
Serial.begin(9600);
delay(1500);
Serial.println("Program begin...");
delay(1000);
Serial.println("This program will start the ESC.");
pinMode(MOTOR_PIN1, OUTPUT);
pinMode(MOTOR_PIN2, OUTPUT);
pinMode(MOTOR_PIN3, OUTPUT);
pinMode(MOTOR_PIN4, OUTPUT);
motor1.attach(MOTOR_PIN1);
motor2.attach(MOTOR_PIN2);
motor3.attach(MOTOR_PIN3);
motor4.attach(MOTOR_PIN4);

Serial.print("Now writing maximum output: (");Serial.print(MAX_SIGNAL);Serial.print(" us in this case)");Serial.print("\n");
Serial.println("Turn on power source, then wait 2 seconds and press Enter");
motor1.writeMicroseconds(MAX_SIGNAL);
motor2.writeMicroseconds(MAX_SIGNAL);
motor3.writeMicroseconds(MAX_SIGNAL);
motor4.writeMicroseconds(MAX_SIGNAL);

// Wait for input
while (!Serial.available());
Serial.read();

// Send min output
Serial.println("\n");
Serial.println("\n");
Serial.print("Sending minimum output: (");Serial.print(MIN_SIGNAL);Serial.print(" us in this case)");Serial.print("\n");
motor1.writeMicroseconds(MIN_SIGNAL);
motor2.writeMicroseconds(MIN_SIGNAL);
motor3.writeMicroseconds(MIN_SIGNAL);
motor4.writeMicroseconds(MIN_SIGNAL);
Serial.println("The ESC is calibrated");
Serial.println("----");
Serial.println("Now, type a values between 1000 and 2000 and press enter");
Serial.println("and the motor will start rotating.");
Serial.println("Send 1000 to stop the motor and 2000 for full throttle");

}

void loop() {

if (Serial.available() > 0)
{
int DELAY = Serial.parseInt();
if (DELAY > 999)
{
motor1.writeMicroseconds(DELAY);
motor2.writeMicroseconds(DELAY);
motor3.writeMicroseconds(DELAY);
motor4.writeMicroseconds(DELAY);
float SPEED = (DELAY-1000)/10;
Serial.print("\n");
Serial.println("Motor speed:"); Serial.print(" "); Serial.print(SPEED); Serial.print("%");
}
}
}
'''

8

Please read the forum guidelines and post your code accordingly.

9

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