Firstly, I would like to say this is my first time trying to work with Arduino on my own.
Nonetheless, I'm currently trying to work on creating a remote controlled car based on the following video: Video.
While I am able to get my motors properly working and the joystick control, my main issue is that the receiver and transmitters, which are NRF24L01's aren't able to communicate properly. I believe I have my connections correct (for the record they are soldered) and that they mimic exactly what the video shows. Here are my sketches for the receiver and transmitter below:
/*Arduino JOYSTICK CONTROLLED CAR (TRANSMITTER)*/
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
RF24 radio(8,9); // CE, CSN
const byte address[6] = "12345";
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
Serial.print("\n" + xAxis);
yAxis = analogRead(A0); // Read Joysticks Y-axis
Serial.print("\n" + yAxis);
// 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);
}
/*ARDUINO JOYSTICK CONTROLLED CAR (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] = "12345";
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
Serial.print("RECIEVED");
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]);
Serial.print(xAxis + "\n");
Serial.print(yAxis + "\n");
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
Serial.print("\n");
Serial.print(motorSpeedA);
Serial.print("\n");
Serial.print(motorSpeedB);
}
For the outputs on the serial monitor, I am getting the correct values for the transmitter, but the receiver is stuck at 0 for one axis and 510 for the other axis. While I do believe this is definitely an issue with the transmission of data, I would appreciate any help to try to get the data to work properly. Thank you for your help and any questions please ask!
Edit: For the record I am using an Arduino Nano for both the transmitter and receiver.