Hi everyone,
I have built myself an RC car using two arduino nanos and two NRF24L01 chips. I based my project off of this rc car on this website http://meedantech.com/ and i am using the code he provided. I have come across an issue where my transmitter will work when it runs of of an external power source- it only works when it is plugged into the computer. Could anyone look over the code and tell me if there could be something wrong in it? This project must be done by FRIDAY, so any help is greatly appreciated! Thanks!
Code and instructions- http://meedantech.com/
Transmitter Code
/*
#include <nRF24L01.h>
#include <RF24.h>
#include <RF24_config.h>
Written by: Mujahed Altahle
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/
or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA.
*/
/* A simple Project for Remote Controlling with nRF24L01+ radios.
We have 2 nodes, the transmitter (this one) and the receiver which is attached to the Car.
The idea is to transmit 2 parameters , one is Direction (Backward, or Forward with the speed) the other is the Steering (Left, or Right with the degree of rotation).
The nRF24L01 transmit values in type of "uint8_t" with maximum of 256 for each packet, so the values of direction is divided by (10) at the Tx side,
then it is multiplied by 10 again at the Rx side.
The Rx rules is to output the received parameters to port 3 and 6 where the Servo and the ESC are are attached
a condition is required to prevent the controller from transmitting values that is not useful (like 1480-1530 for ESC and 88-92 for Servo) to save more power as much as we can
*/
#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"
//
// Hardware configuration
//
// Set up nRF24L01 radio on SPI bus plus pins 9 & 10
RF24 radio(9,10);
uint8_t data[2] ; //buffer to store received data
const uint8_t buffer_size = sizeof(data);
//pins that used for the Joystick
const int analogInPinY= A0; //
const int analogInPinX = A1;//
const int StearRight = 3;
const int StearLeft = 5;
const int tx_led=2;// transmission indicator
int Y_value = 0; // values read from the pot
int X_value = 0;
int outputValue = 0;
/*
const int transmit_pin=6;
int transmit_enable;
int ForwrdButton=2;
int BackwrdButton=3;
*/
//
// Topology
//
// Single radio pipe address for the 2 nodes to communicate.
const uint64_t pipe = 0xE8E8F0F0E1LL;
//
// Setup
//
void setup(void)
{
Serial.begin(9600);
printf_begin();
//
// Setup and configure rf radio
//
radio.begin();
radio.openWritingPipe(pipe);
//
// Dump the configuration of the rf unit for debugging
//
radio.printDetails();
//
// Set up buttons
//
/*to be used later
pinMode(ForwrdButton,INPUT );
pinMode(BackwrdButton,INPUT);
pinMode(transmit_enable,INPUT);
*/
pinMode(tx_led,OUTPUT);
digitalWrite(tx_led,LOW);
pinMode(StearRight,INPUT);
pinMode(StearLeft,INPUT);
digitalWrite(StearRight,HIGH);
digitalWrite(StearLeft,HIGH);
}
//
// Loop
//
void loop(void)
{
X_value = analogRead(analogInPinX);
data[0] = map(X_value, 0, 1024,100 , 200);
Y_value = analogRead(analogInPinY);
data[1] = map(Y_value, 0, 1024, 135, 45);
if(!StearRight)
data[1]=45;
else if(!StearLeft)
data[1]=135;
// transmit_enable=!digitalRead(transmit_pin);
//an error ratio around +3,-3 appears coming from the Joystick all the time,
//so we neglect them (using the following if statement) because they make the system transmitting data always and they are useless and waste of power
if((data[0]>153 || data[0] <=149) || (data[1]>=92 || data[1]<88))
{
//printf("Now sending...");
bool ok = radio.write( data, buffer_size );
//if (ok)
printf("ok\n\r");
// else
printf("failed\n\r");
// delay(15);
digitalWrite(tx_led,HIGH); //turn led on after transmission
}
else digitalWrite(tx_led,LOW);//keep led off when no transmission
}
Receiver Code
/*
#include <nRF24L01.h>
#include <RF24.h>
#include <RF24_config.h>
Written by: Mujahed Altahle
This work is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/
or send a letter to Creative Commons, 444 Castro Street, Suite 900, Mountain View, California, 94041, USA.
*/
/* A simple Project for Remote Controlling with nRF24L01+ radios.
We have 2 nodes, the transmitter (this one) and the receiver which is attached to the Car.
The idea is to transmit 2 parameters , one is Direction (Backward, or Forward with the speed) the other is the Steering (Left, or Right with the degree of rotation).
The nRF24L01 transmit values in type of "uint8_t" with maximum of 256 for each packet, so the values of direction is divided by (10) at the Tx side,
then it is multiplied by 10 again at the Rx side.
The Rx rules is to output the received parameters to port 3 and 6 where the Servo and the ESC are are attached
a condition is required to prevent the controller from transmitting values that is not useful (like 1480-1530 for ESC and 88-92 for Servo) to save more power as much as we can
*/
#include <Servo.h>
#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"
//
// Hardware configuration
//
// Set up nRF24L01 radio on SPI bus plus pins 9 & 10
RF24 radio(9,10);
Servo servo; //steering servo declaration
Servo esc; // Electronic Speed Contoller declaration
// Single radio pipe address for the 2 nodes to communicate.
const uint64_t pipe = 0xE8E8F0F0E1LL;
//
// Payload
//
uint8_t received_data[2];
uint8_t num_received_data =sizeof(received_data);
//
// Setup
//
void setup(void)
{
delay(3000); //wait until the esc starts in case of Arduino got power first
servo.attach(3); // attaches the servo on pin 3 to the servo object
esc.attach(6); // attaches the ESC on pin 6 to the ese object
servo.write(90);
//
// Print preamble
//
Serial.begin(57600);
printf_begin();
//
// Setup and configure rf radio
//
radio.begin(); //Begin operation of the chip.
// This simple sketch opens a single pipes for these two nodes to communicate
// back and forth. One listens on it, the other talks to it.
radio.openReadingPipe(1,pipe);
radio.startListening();
//
// Dump the configuration of the rf unit for debugging
//
radio.printDetails();
}
void loop(void)
{
// if there is data ready
if ( radio.available() )
{
bool done = false;
int ESC_value;
while (!done)
{
// Fetch the payload, and see if this was the last one.
done = radio.read( received_data, num_received_data );
ESC_value=received_data[0]*10; //Multiplication by 10 because the ESC operates for vlues around 1500 and the nRF24L01 can transmit maximum of 255 per packet
esc.writeMicroseconds(ESC_value);
// Serial.println(ESC_value);
servo.write((received_data[1]));
// Serial.println(received_data[1]);
}
}
}
