Distance calculation

[vipin]

Can you specify any chip in which we can have distance parametre also from receiver to Transmitter.

Please provide any link for its Evaluation board also.

Regards, Vipin

[vipin]

I need this for RFID Application as if now i am using NRF24LU1P

[Øyvind Karlsen]

Hi,

The range for a radio system is obtained from a formula called Friis transmission equation, this equation depends largely on the frequency(higher frequency means lower range) and the link budget(difference between transmitted power and radio sensitivity minus added noise). The different link budgets(best case scenario), without added, noise are nRF24L01+ - 94dBm, nRF51 - 94dBm and nRF52 - 100dBm. This suggests that if you need the extra range, you would go for the nRF52 chip. See this post for some range calculations for the older nRF905.

A link budget close to 100dB at 2.4GHz means that you can get systems with 30m range in real world conditions.

Best regards,

Øyvind

[awneil]

I think the question was how to measure the distance between receiver & transmitter in real time...?

[Øyvind Karlsen]

Well, you could estimate the distance using RSSI, however this will be highly inaccurate. If you use several nRF5 series chips in a mesh with known locations you can triangulate to find the posistion.