NRF51 UART TO RS485 - Handling Arbitration

[Siva]

Hi All,

I have just got my nRF51 kit (S130) and started working on a beacon project which would transmit advertisements packets from peripherals over a RS485 to a server. The RS485 chip would be connected to the UART pins and I would be using the Nordic UART driver for transmission and reception to and from the server. Since there would be a number of beacon devices on the RS485 bus having a descent amount of traffic, I am worried about the arbitration on the RS485 bus. Does the Nordic offer any means to handle the arbitration and collision in scenarios like this?

Thanks in advance

[Sigurd]

Hi,

Your plan is to physically wire all the beacons, and use RS485 to connect them to a server?

I don’t think we have anything to handle the RS485 bus arbitration. Depending on your use-case, there might be better options then to use RS485.

[Siva]

Hi Sigurdon,

Thanks for your reply. Yes, we are physically wiring all the beacons on the RS485 cable. Unfortunately we have to stick to RS485 since that''s the requirement.

[Sigurd]

The scope of the UART on the nRF5x is simple point to point (RS232) serial communication, not the industrial standards for multidrop and serial networks (RS422, RS485). Nordic does therefore not offer any examples or solutions with RS485.