Hey All,
I have done some playing and based upon the Mirf Library I have created a sketch that reads a register of the nRf24l01 without the use of a library.
Why...Because I wanted to understand how it worked, I spent many hours using libraries that either didn't work or I couldn't understand how they worked so I broke down the Mirf library and created this sketch.
I hope someone finds this as useful as I did.
For the test I used 3 components;
- Arduino Nano
- 3.3V Regulator
- nRF24L01 Module
I also have a server/slave wireless code which may be useful that transmits strings and sensor data.
The code is verified on Arduino 1.6.5
Ensure you have the correct csnPin & cePin wired to the module
**Note: I am not claiming this as my own ideas as it is entirely based on the Mirf library found below.
//Read a register on the nRF24l01 without using a library
#include <SPI.h>
uint8_t csnPin = 10;
uint8_t cePin = 9;
uint8_t channel = 90 ;
uint8_t addLength = 5;
char * address = "00001";
uint8_t payload;
uint8_t PTX;
void setup()
{
Serial.begin(9600);
Serial.println( "Starting wireless..." );
//initialisation code
pinMode(cePin, OUTPUT);
pinMode(csnPin, OUTPUT);
ceLow();
csnHi();
SPI.begin();
SPI.setDataMode(SPI_MODE0);
SPI.setClockDivider(SPI_2XCLOCK_MASK);
setRaddress((byte *)address);
payload = sizeof(unsigned long);
config();
byte rfsetup = 0;
//
//
//
//CHANGE 0x05 to any Register you want to Read
readregister(0x05, &rfsetup, sizeof(rfsetup));
//
//
//
//
Serial.print( "rf_setup = " );
Serial.println( rfsetup, BIN );
Serial.println( "Wireless initialized!" );
Serial.println(payload, BIN);//Output from register
Serial.println(payload, DEC);//Same as above but in different formats
Serial.println(payload, HEX);
}
void loop()
{
}
//reads an array of bytes from the given start position in the registers
void readregister(uint8_t reg, uint8_t * value, uint8_t len)
{
csnLow();
spisend(0x00 | ( 0x1F & reg));
transfersync(value, value, len);
csnHi();
}
void transfersync(uint8_t *dataout, uint8_t *datain, uint8_t len)
{
uint8_t i;
for (i = 0; i < len; i++)
{
datain[i] = spisend(dataout[i]);
}
}
void config()
{
configregister(0x05, channel); //Set the RF channel to 90
configregister(0x11, payload);
configregister(0x12, payload);
poweruprx();//to do
flushrx(); // to do
}
void flushrx()
{
csnLow();
spisend(0xE2);
csnHi();
}
void poweruprx()
{
PTX = 0;
ceLow();
configregister(0x00, 0x07 | ((1 << 0x01) | (0 << 0)));
ceHi();
configregister(0x07, (1 << 0x05) | (1 << 0x04)) ;
}
void configregister(uint8_t reg, uint8_t value)
{
csnLow();
spisend(0x20 | (0x1F & reg));
spisend(value);
csnHi();
}
void setRaddress(uint8_t * adr)
{
ceLow();
writeRegister(0x0B, adr, addLength);
ceHi();
}
void writeRegister(uint8_t reg, uint8_t * value, uint8_t len)
{
csnLow();
spisend(0x20 | (0x1F & 0x0B));
transmitsync(value, len);
csnHi();
}
//Need to see if this works
uint8_t spisend(uint8_t data)
{
return SPI.transfer(data);
}
void transmitsync(uint8_t *dataout, uint8_t len)
{
uint8_t i;
for (i = 0; i < len; i++)
{
spisend(dataout[i]);
}
}
//Functions to control the chip select pins
void ceHi() {
digitalWrite(cePin, HIGH);
}
void ceLow() {
digitalWrite(cePin, LOW);
}
void csnHi() {
digitalWrite(csnPin, HIGH);
}
void csnLow() {
digitalWrite(csnPin, LOW);
}
Cheers
Chambo
