nRF51822 2.4Ghz radio questions

[CR]

Hi!

I am using the nRF51822 to do some measurements regarding the capture effect (en.wikipedia.org/.../Capture_effect).

My question now is: when does the radio latches onto a signal? Is it after a few bits of the preamble, the full preamble or even later? In 802.15.4 there is somethings as an Start of Frame Delimiter (SFD) and in classic Bluetooth there is a sync word but it is different in Bluetooth LE.

Furthermore, what is exactly the difference between the NRF 1Mbit and the BLE 1Mbit radio mode? Does something changes in the 2.4GHz radio block?

[Asbjørn]

It uses the preamble to lock the receiver on the signal and starts comparing bits at the end of the preamble. It's pretty much the same as what's known as synch words.

The difference between the two modes of operation you refer to is the signal deviation. See chapter 8.5.1 in the nRF51822 product specification.