Troubleshooting Smart Car Remote Programming: Getting Both Sides Moving

Creating a remote-controlled smart car for a class project, especially one involving cool tech like 3D printing, is an exciting endeavor. It’s common to hit a few snags along the way, and it sounds like you’ve encountered a frustrating one with your IR remote control car. You’ve programmed your Elegoo car, but only one side of the wheels is responding to the remote commands. Let’s dive into debugging this issue and get all wheels working in sync for your smart car project.

You mentioned that you’ve already explored libraries and online code examples, landing on one that gets the left wheels moving correctly – forward, back, and turning. That’s a great starting point! The problem, as you’ve described, is that the right wheels remain unresponsive. You’ve even checked the motor control and confirmed it’s functional, and an auto-go test showed all wheels working. This points away from a hardware failure and more towards a potential issue in the Smart Car Remote Programming logic for motor control.

Let’s examine the Arduino code you provided to pinpoint where things might be going wrong:

#include <IRremote.h>

#define F 16736925
#define B 16754775
#define L 16720605
#define R 16761405
#define S 16712445
#define UNKNOWN_F 5316027
#define UNKNOWN_B 2747854299
#define UNKNOWN_L 1386468383
#define UNKNOWN_R 553536955
#define UNKNOWN_S 3622325019
int RECV_PIN = 12;
int in1=6;
int in2=7;
int in3=8;
int in4=9;
int ENA=5;
int ENB=11;
int ABS=250;

IRrecv irrecv(RECV_PIN);
decode_results results;
unsigned long val;

void _mForward() {
  analogWrite(ENA,ABS);
  analogWrite(ENB,ABS);
  digitalWrite(in1,HIGH);//digital output
  digitalWrite(in2,LOW);
  digitalWrite(in3,HIGH);
  digitalWrite(in4,HIGH);
  Serial.println("go forward!");
}
void _mBack() {
  analogWrite(ENA,ABS);
  analogWrite(ENB,ABS);
  digitalWrite(in1,LOW);
  digitalWrite(in2,HIGH);
  digitalWrite(in3,LOW);
  digitalWrite(in4,HIGH);
  Serial.println("go back!");
}
void _mleft() {
  analogWrite(ENA,ABS);
  analogWrite(ENB,ABS);
  digitalWrite(in1,HIGH);
  digitalWrite(in2,LOW);
  digitalWrite(in3,HIGH);
  digitalWrite(in4,LOW);
  Serial.println("go left!");
}
void _mright() {
  analogWrite(ENA,ABS);
  analogWrite(ENB,ABS);
  digitalWrite(in1,LOW);
  digitalWrite(in2,HIGH);
  digitalWrite(in3,LOW);
  digitalWrite(in4,HIGH);
  Serial.println("go right!");
}
void _mStop() {
  digitalWrite(ENA,LOW);
  digitalWrite(ENB,LOW);
  Serial.println("STOP!");
}

void setup() {
  pinMode(in1,OUTPUT);
  pinMode(in2,OUTPUT);
  pinMode(in3,OUTPUT);
  pinMode(in4,OUTPUT);
  pinMode(ENA,OUTPUT);
  pinMode(ENB,OUTPUT);
  _mStop();
  irrecv.enableIRIn();
  Serial.begin(9600);
}

void loop() {
  if (irrecv.decode(&results)){
    val = results.value;
    Serial.println(val);
    irrecv.resume();
    switch(val){
      case F:
      case UNKNOWN_F:
        _mForward();break;
      case B:
      case UNKNOWN_B:
        _mBack(); break;
      case L:
      case UNKNOWN_L:
        _mleft(); break;
      case R:
      case UNKNOWN_R:
        _mright();break;
      case S:
      case UNKNOWN_S:
        _mStop(); break;
      default:break;
    }
  }
}

Analyzing the Code and Potential Issues

Looking at your code, the structure seems correct for controlling a four-wheel drive car using an L298N motor driver or similar. Here’s a breakdown and things to consider:

• Motor Control Pins: You’ve defined pins in1, in2, in3, in4 for direction control and ENA, ENB for enabling/PWM speed control. It’s crucial to verify these pin assignments match your wiring to the motor driver and motors.

• Direction Logic: The _mForward(), _mBack(), _mleft(), _mright(), and _mStop() functions define the logic for each movement. In functions like _mForward() and _mBack(), you’re setting pins in1/in2 and in3/in4. It’s important to understand which pair controls which set of wheels (left vs. right). The code as written appears to control both left and right sides simultaneously in forward/backward motion.

• Turning Logic (_mleft() and _mright()): In your _mleft() function, you set digitalWrite(in4,LOW); and in _mright() you also set digitalWrite(in4,HIGH);. This is where a potential issue might lie. Typically, to turn, you need to have one side of wheels move forward (or backward) while the other side either stops or moves in the opposite direction. Your current _mleft() and _mright() functions might not be creating differential movement between the left and right wheels, which is needed for turning.

Troubleshooting Steps to Get Both Sides Working

1. Wiring Check (Most Likely Issue):

   • Double-check your wiring. Ensure that in1, in2 are indeed controlling one set of wheels (e.g., left) and in3, in4 control the other (right). It’s very easy to miswire these.
   • Verify Motor Driver Connections: Make sure ENA and ENB are correctly connected to the enable pins of your motor driver, and that the motor power supply is adequate.

2. Code Logic for Turning:

   • Review _mleft() and _mright() functions: For turning, you likely want something like this (this is a general example, adjust based on your motor driver and wiring):
     • _mleft(): Left wheels stop or move backward, right wheels move forward.
     • _mright(): Right wheels stop or move backward, left wheels move forward.
   • Modify _mleft() and _mright(): Experiment with different digitalWrite() combinations in these functions to achieve differential movement. For example, to turn left, you might try stopping the left wheels (digitalWrite(in1, LOW); digitalWrite(in2, LOW);) while making the right wheels move forward (digitalWrite(in3, HIGH); digitalWrite(in4, LOW); or digitalWrite(in3, LOW); digitalWrite(in4, HIGH); depending on your motor direction).

3. Pin Definitions:

   • Confirm Pinouts: Re-examine your Arduino and motor driver pinouts to ensure that in1, in2, in3, in4, ENA, and ENB are assigned to the correct Arduino digital pins and connected to the corresponding motor driver inputs.

4. Motor Driver Module:

   • Although you mentioned motor control is fine, re-verify the motor driver. If possible, test the motor driver independently with a simpler sketch to ensure it’s functioning correctly for both channels (Channel A and Channel B, usually controlling left and right sides).

By systematically checking your wiring and refining the smart car remote programming logic, especially the turning functions, you should be able to get both sides of your Elegoo car responding to the IR remote. Debugging is a key part of any project, and you’re on the right track! Keep experimenting and testing, and you’ll have your smart car moving smoothly in no time.