Interfacing an nRF51 with an ESP8266 using AT commands over UART

[Sensors]

Right now I'm trying to interface an nRF51822 set up as a central to an ESP8266 module. The module is controlled by AT commands, and usually issues a response.

I'm struggling to figure out how to determine if a command has been a success. The arduino way of doing things is usually much higher level and allows there to just be a short delay implemented followed buy a string comparison.

How would I achieve a similar thing with the UART interrupts and a soft device running too?

I need to send a series of AT commands, and the response varies with each command.

[awneil]

Nothing specific to ESP8266 - it's the same for any device using AT Commands:

You need to study the AT Commands Manual for the device: that will tell you what response(s) can be returned by each command - and which of those indicate "success" or "failure".

The key thing is not to rely upon delays - always pay attention to the responses.

[Sensors]

That was what I wanted to do. But it's awkward when the ESP8266 seems to echo back everything that is sent, and has a different response for each command. I suppose what I can't figure out is how to actually implement this checking when the commands are sent. Are you aware of any resources that might point me in the right direction with this?

[awneil]

There is usually an AT Command to turn off echo - ATE0

It is in the nature of AT commands that different commands do different things - so they will naturally have different responses to indicate what they've done, or what has failed.

Same applies to other command-response systems, really ...

[Sensors]

That's helpful to know, thanks.

You don't happen to have any examples of how to deal with AT responses, do you? I'm still unable to figure this out unfortunately. I just can't see how to utilise the UART Rx callback to record the stream of character responses, and then check this against what I might expect the response to be...

[awneil]

Not off hand - but I would look first at using a State Machine. Use the response termination character as the cue to review the received string ...

Not sure how mbed does it - you could take a look: developer.mbed.org/.../