what's access address and channel?

[Mitch996]

Regarding the radio peripheral, I stumbled upon these 2 properties and have no idea what they are for.

What's access address? And what is a channel? Shouldn't there be "channels" since the radio peripheral of nrf51 devices works by frequency-hopping?

One last thing, the radio peripheral can transmitt raw data without any thing right? That is, it can air "0x0823" and just that, without revealing anything about itself, i.e. the mac address, since mac addresses are a concept well within the domain of BLE, and BLE isn't possible without first enabling softdevice?

[Jørgen Holmefjord]

Hi,

With access address I guess you refer to the on-air radio address. The radio can be configured to listen for certain addresses, where only address matches will be accepted. For instance, when the radio is in BLE mode, you only care about data sent from other BLE devices. BLE use the "access address" 0x8e89bed6, so the radio only have to listen for packets that match this address. Configuration of on-air radio address is described in chapter 17.1.4 of the nRF51 Reference Manual v3.0.

A channel is a specified frequency that the radio transmitts/receives at. The nRF51 radio does not use frequency-hopping by default. BLE use FHSS, while ANT use fixed-frequency. Proprietary radio protocols can implement both FHSS and fized-frequency.

Yes, you can transmitt RAW data. Look at the Radio Transmitt/Radio Receive examples.

Best regards,

Jørgen