Arduino Motor Control at a Specific Time

Question

Hello. Currently I'm working on creating an automatic dog food dispenser. I'm using a Arduino Uno R3, an L298N stepper driver, a DS1307 RTC breakout board, a Nema 17 stepper motor, and a breadboard to disperse the power to each board. I'm using a 9V battery to power it temporarily. I've tested motor control without it being determined by the current time and it works perfectly however when I have the motor run at a specific time (4:45 and 6:45 in the code) the motor doesn't move. How can I move the motor at these specific times?

#include <RTClib.h>
#include <Stepper.h>
#include <SoftwareSerial.h>

RTC_DS1307 rtc;

Stepper myStepper(200 , 9 , 10 , 11 , 12);

void setup() {                                                
  Serial.begin(9600);                                       
  rtc.adjust(DateTime(2021 , 7 , 14 , 4 , 44 , 0));
  myStepper.setSpeed(20);
}

void loop() {

  DateTime now = rtc.now();

  if ((now.hour() == 4 and now.minute() == 45) or (now.hour() == 6 and now.minute() == 45)) {
      Serial.println("testing");
      myStepper.step(10000);
      delay(1000);

}


}

Answer 1

You are pushing the limit of the L298N, probably will exceed it. A typical stepper motor like a NEMA 17 is probably rated at voltage of about 2.8 Volts and a maximum current of 1.68 Amps. This basically means if you hook it up to 2.8 Volts it will draw 1.68 Amps. If you try to run it at a higher voltage it will draw more current and get excessively hot. Driver Model: L298N has a Motor Supply Current (Maximum): 2A, Logic Voltage: 5V, Driver Voltage: 5-35V. The motor was rated at about 2.8V, powering it with more will very quickly exceed your bridge capacity. The Arduino will give you 5V and 3.3V but using either to power your motor will probably destroy the Arduino. The Arduino a power supply it is NOT! I suggest you use a seperate power supply for the motor. If you power the Arduino via Vin and use a buck converter from the 12V it should work fine.

Answer 2

I’m new at this but looks to me like your rtc is uses i2c comms. I don’t see that you’ve included wire.h or issued the wire.begin to initiate communication between the rtc and arduino. See other rtc examples and good luck!