nrf51822's carrier detect

[lishuangjiang]

hello, I have some quesetion about the nrf51822's carrier detect. I want to use " CSMA" to avoid

Communication collision, the datasheet has no detailed infomation about the carrier detect. the

RSSI module of nrf51822 can work after the address match

ths

[Stian Røed Hafskjold]

BLE uses frequency hopping to avoid interference, not carrier detect. The receiver has a sensitivity that tells how much the signal strength between two simultaneous packets on the same channel has to differ in order for the radio to be able to receive the packet. In nRF51822 PS section 8.5.5 it is specified as 12dB. So, if two packets are sent at the same time on the same channel and the signal strength is less then 12dB difference, you will get a packet loss.

[AndrewF]

Actually, for 250kbps mode it is 4dB.