Howto properly parse response data received from GSM module?
.net-micro-framework, at-command, c#, gsm, parsing
Solution
I found it. My bad assumption was that sms message can contain CrLf within. This is not true (at least for uBlox SARA-G350). All CrLf within some text received from module are replaced to Lf.
Thanks to that I can know that end of sentence will be when one of the next combinations arrives:
- `<CR><LF>OK<CR><LF>`
- `<CR><LF>ERROR<CR><LF>`
- `<CR><LF> >`
The last one is prompt sign for sms sending command.
Problem
I'm looking for some guidelines how to properly parse response data received from GSM module. I'm using uBlox SARA-G350. Documentation states: ``` Information responses: <CR><LF><text><CR><LF> Result codes: <CR><LF><verbose code><CR><LF> If the command line is successfully performed, the string "OK" (<CR><LF>OK<CR><LF>) is sent, otherwise "ERROR". ``` It might looks everything simple. We should read each sentence from `<CR><LF>` to `<CR><LF>` but... - data may become in chunks - response may contains doubled `<CR><LF>OK<CR><LF>` (see example below) Example - sms message sent to gsm module: ``` "Hi. Is IT OK " ``` After CMGL module respond (this is how end of sequence of returned data might looks like): ``` Hi. Is IT<CR><LF> OK<CR><LF> <CR><LF> OK<CR><LF> ``` As you can see we have doubled `<CR><LF>OK<CR><LF>`. How do I know that I have whole sentence and should stop reading data from module and do parsing received data? How AT parser should behave in situation like this? Where I can find some guidelines how to properly parse incoming response data from gsm module?