Sending SAADC data over BLE

RE: Sending SAADC data over BLE

Tormod123 — Wed, 11 Mar 2020 12:11:02 GMT

Simply postponing the samling until a connection was made seemed to do it. I simply set saadc_sampling_event_enable under the ble_evt_handler in the connected case. Do you also think it would be better practice to set the two init functions, saadc_sampling_event_init and saadc_init inside here too?

So when a central now connects to the periphral device the samling is started and values from the potmeter is getting sent and recieved on the central end. However the central is receiving some wierd values:

I would imagine its some kind of formatting issue maybe.

Here is what is I see on the peripheral side:

It seems like the values on the left is getting sent.

RE: Sending SAADC data over BLE

Jørgen Holmefjord — Tue, 10 Mar 2020 09:22:20 GMT

Ok, that makes sense. Error 5 corresponds to NRF_ERROR_NOT_FOUND, and this is returned from ble_nus_data_send() if the connection_handle parameter is not valid:

if ((conn_handle == BLE_CONN_HANDLE_INVALID) || (p_client == NULL))
{
    return NRF_ERROR_NOT_FOUND;
}

You can either filter this error similar to NRF_ERROR_INVALID_STATE, before passing the err_code variable to APP_ERROR_CHECK, or you can postpone starting of the SAADC sampling (calling saadc_sampling_event_enable()) until you are in a connection and have enabled notifications for the NUS service. If the only purpose of sampling the SAADC is to transfer the data over BLE, there is no point in having it running when you are not in a connection. In this case, you should also stop the sampling whenever the device disconnects.

RE: Sending SAADC data over BLE

Tormod123 — Mon, 09 Mar 2020 22:24:33 GMT

Here is the error code im getting, 0x00000005. I tried to search up what that was but did not find any documentation. So what I think is happening is that the ble_nus_data_send does not work as intended since it catches an error, 0x0000005.

Im guessing im sending some wrong arguments here, though I dont know which one is wrong.

RE: Sending SAADC data over BLE

Jørgen Holmefjord — Mon, 09 Mar 2020 15:19:46 GMT

Hi,

Can you build the application with the DEBUG flag set in the project preprocessor symbols (you can use Debug build configuration if using SES)? You should then get the error code and exact line output on the log.

Best regards,
Jørgen