RE: can any one please tell me how to identify the nRF24L01 uniquely

Derek Goslin — Mon, 08 Dec 2014 22:26:28 GMT

Hi NISHIL

The nRF24L01 devices do not have a unique id, I am currently working in a similar project. You will have to come up with another scheme to uniquely identify a node/device using an nrf24l01 module.

A few options:

A unique ID chip such as this
Program an ID per device
Generate a unique ID using some seed data and then store in device eeprom

I use the generation mechanism, basically I sample the ADC as the source of the seed values.

uint16_t rng16(uint16_t seed)
{
	// Call four times with non-zero args to seed.
	// Period is greater than one quintillion.
	static uint32_t k=1148543851;
	static uint32_t i=1234567891;
	if(seed)
	{
		i=(i<<16)+((k<<16)>>16);
		k=(k<<16)+seed;
		return(0);
	}
	
	k=30903*(k&65535)+(k>>16);
	i=31083*(i&65535)+(i>>16);
	return(k+i);
}

uint16_t system_generate_id()
{
	uint16_t voltage = 0;
	
	for (uint8_t i = 0; i < 4; i++)
	{
		system_read_battery_voltage(&voltage);
		rng16(voltage);
	}
	
	return rng16(0);
}

The above rng16 function is based on work by George Marsaglia. The method of seeding would not be useful for cryptographic uses but it was random enough for what I needed, which was a unique device ID.