Unable to communicate SIM800L Core Board with nRF52 through UART

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Fri, 17 Mar 2017 10:49:08 GMT

Normally, GSM modules/modems give a '>' prompt when they are ready to receive the "payload" of an SMS.

Doesn't the SIM800 do this?

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Fri, 17 Mar 2017 10:47:24 GMT

ignoring the replies from the module

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

saiteja — Fri, 17 Mar 2017 08:54:02 GMT

can you please point my mistake.

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Fri, 17 Mar 2017 08:35:36 GMT

You are making the all-too-common mistake of ignoring the replies from the module.

That's like trying to drive down a busy street with your eyes closed, turning the steering wheel only at set times ...

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

saiteja — Fri, 17 Mar 2017 07:30:23 GMT

hi tq, its working fine but when i send SMS i stuck with CTRL+Z. i even tried (char)26 and also 0X1A.

here is my code: ////Message

uart_putstring((uint8_t*)"AT\r");
nrf_delay_ms(2000);
uart_putstring((uint8_t*)"AT+CMGF=1\r");
       nrf_delay_ms(2000);
uart_putstring((uint8_t*)"AT+CMGS=\"8919242248\"\r");
   nrf_delay_ms(2000);
   uart_putstring((uint8_t*)"test\r");
          nrf_delay_ms(2000);
          app_uart_put((char)0x1A);   ///used (uint8_t) 26 also but no response..
                 nrf_delay_ms(1000);

if run this terminal is showing this:

AT+CMGF=1

AT+CMGS="8919242248"

test

·rx_data: AT

AT+CMGF=1

AT+CMGS="8919242248"

test

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Thu, 16 Mar 2017 08:59:47 GMT

(see above)
The trouble with the nRF52 (and nRF51) is that it has only 1 UART. So, once you have tied this to your SIM800, you have no alternative for debug output. Therefore you will need to learn to use SWO. See devzone.nordicsemi.com/.../
Next, just connect the nRF52 to a PC terminal - forget the SIM800. Get your nRF52 reliably sending commands to the PC terminal, and accepting responses that you send from the terminal. Use SWO so that you have visibility of what is being sent & received.
Now (and only now) connect the nRF52 to the SIM800. Verify that sending commands from the nRF52 to the SIM800, and receiving the responses works solidly.
Now (and only now) you are in a position to start adding Bluetooth ...

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Thu, 16 Mar 2017 08:55:07 GMT

You are making the all-too-common mistake of trying to do too much all at once. As you are uncertain about how to get the basic UART wired communication working, you should concentrate just on that at first - don't complicate the issue by trying to do Bluetooth as well! You also need to be sure that you have a reliable and usable way to monitor the comms between the nRF and SIM800. The way to proceed is:

Forget the nRF52. Just make sure that you can send command to the SIM800, and read its responses, using a PC terminal. Make sure that you understand the commands that you will need to send, and the responses that you will get. Pay particular attention to line ending characters (it helps if you have a terminal or monitor that can display raw hex).

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Thu, 16 Mar 2017 07:25:20 GMT

APP_UART_FLOW_CONTROL_ENABLED

So you have enabled flow control - but you have not connected any of the flow control signals!

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

saiteja — Wed, 15 Mar 2017 18:33:23 GMT

Hey, thank you again for the response. I have edited the Q? Shown my connections schematic.

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Wed, 15 Mar 2017 18:23:43 GMT

That is not helpful.

Again, remember that you are the only one who has access to your hardware. Nobody else can do these checks for you. Also, nobody else can see what is happening in your system, nor how it is connected - so it is important that you provide complete, detailed, unambiguous, and accurate descriptions.

We can't read your mind!

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

saiteja — Wed, 15 Mar 2017 18:05:54 GMT

I have connected termite to the dk board.

RE: Unable to communicate SIM800L Core Board with nRF52 through UART

awneil — Wed, 15 Mar 2017 17:28:24 GMT

Duplicate: devzone.nordicsemi.com/.../

A proper schematic would be more useful that just a photo - we have no idea what the pins on the red board are!

you haven't said where you are connecting Termite!