I've been trying to create a remote controlled arduino car by following a youtube video. All the wiring is connected connected correctly, but the code that came with the video is wrong. It causes two of the wheels to spin while not receiving any commands from the joystick.
I'm completely clueless when it comes to coding, so I was really hoping if someone from this forum could possibly help me fix the code? It would be greatly appreciated.
According to a commenter who managed to fix the code. It has something to do with the x and y axis being swapped?
Receiver:
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#define enA 2
#define in1 3
#define in2 4
#define enB 7
#define in3 5
#define in4 6
RF24 radio(8, 9); // CE, CSN
const byte address[6] = "00001";
char receivedData[32] = "";
int xAxis, yAxis;
int motorSpeedA = 0;
int motorSpeedB = 0;
void setup() {
pinMode(enA, OUTPUT);
pinMode(enB, OUTPUT);
pinMode(in1, OUTPUT);
pinMode(in2, OUTPUT);
pinMode(in3, OUTPUT);
pinMode(in4, OUTPUT);
Serial.begin(9600);
radio.begin();
radio.openReadingPipe(0, address);
radio.setPALevel(RF24_PA_MIN);
radio.startListening();
}
void loop() {
if (radio.available()) { // If the NRF240L01 module received data
radio.read(&receivedData, sizeof(receivedData)); // Read the data and put it into character array
xAxis = atoi(&receivedData[0]); // Convert the data from the character array (received X value) into integer
delay(10);
radio.read(&receivedData, sizeof(receivedData));
yAxis = atoi(&receivedData[0]);
delay(10);
}
// Y-axis used for forward and backward control
if (yAxis < 470) {
// Set Motor A backward
digitalWrite(in1, HIGH);
digitalWrite(in2, LOW);
// Set Motor B backward
digitalWrite(in3, HIGH);
digitalWrite(in4, LOW);
// Convert the declining Y-axis readings for going backward from 470 to 0 into 0 to 255 value for the PWM signal for increasing the motor speed
motorSpeedA = map(yAxis, 470, 0, 0, 255);
motorSpeedB = map(yAxis, 470, 0, 0, 255);
}
else if (yAxis > 550) {
// Set Motor A forward
digitalWrite(in1, LOW);
digitalWrite(in2, HIGH);
// Set Motor B forward
digitalWrite(in3, LOW);
digitalWrite(in4, HIGH);
// Convert the increasing Y-axis readings for going forward from 550 to 1023 into 0 to 255 value for the PWM signal for increasing the motor speed
motorSpeedA = map(yAxis, 550, 1023, 0, 255);
motorSpeedB = map(yAxis, 550, 1023, 0, 255);
}
// If joystick stays in middle the motors are not moving
else {
motorSpeedA = 0;
motorSpeedB = 0;
}
// X-axis used for left and right control
if (xAxis < 470) {
// Convert the declining X-axis readings from 470 to 0 into increasing 0 to 255 value
int xMapped = map(xAxis, 470, 0, 0, 255);
// Move to left - decrease left motor speed, increase right motor speed
motorSpeedA = motorSpeedA + xMapped;
motorSpeedB = motorSpeedB - xMapped;
// Confine the range from 0 to 255
if (motorSpeedA < 0) {
motorSpeedA = 0;
}
if (motorSpeedB > 255) {
motorSpeedB = 255;
}
}
if (xAxis > 550) {
// Convert the increasing X-axis readings from 550 to 1023 into 0 to 255 value
int xMapped = map(xAxis, 550, 1023, 0, 255);
// Move right - decrease right motor speed, increase left motor speed
motorSpeedA = motorSpeedA - xMapped;
motorSpeedB = motorSpeedB + xMapped;
// Confine the range from 0 to 255
if (motorSpeedA > 255) {
motorSpeedA = 255;
}
if (motorSpeedB < 0) {
motorSpeedB = 0;
}
}
// Prevent buzzing at low speeds (Adjust according to your motors. My motors couldn't start moving if PWM value was below value of 70)
if (motorSpeedA < 70) {
motorSpeedA = 0;
}
if (motorSpeedB < 70) {
motorSpeedB = 0;
}
analogWrite(enA, motorSpeedA); // Send PWM signal to motor A
analogWrite(enB, motorSpeedB); // Send PWM signal to motor B
}
Transmitter:
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
RF24 radio(8,9); // CE, CSN
const byte address[6] = "00001";
char xyData[32] = "";
String xAxis, yAxis;
void setup() {
Serial.begin(9600);
radio.begin();
radio.openWritingPipe(address);
radio.setPALevel(RF24_PA_MIN);
radio.stopListening();
}
void loop() {
xAxis = analogRead(A1); // Read Joysticks X-axis
yAxis = analogRead(A0); // Read Joysticks Y-axis
// X value
xAxis.toCharArray(xyData, 5); // Put the String (X Value) into a character array
radio.write(&xyData, sizeof(xyData)); // Send the array data (X value) to the other NRF24L01 modile
// Y value
yAxis.toCharArray(xyData, 5);
radio.write(&xyData, sizeof(xyData));
delay(20);
}
