I want to transfer data fast with SAADC and BLE UART

RE: I want to transfer data fast with SAADC and BLE UART

Vidar Berg — Tue, 29 Sep 2020 07:37:46 GMT

Hi,

It should have worked. Please try to see if you can view the logs in RTTViewer (is part of the Jlink driver package).

RE: I want to transfer data fast with SAADC and BLE UART

kurotaky — Tue, 29 Sep 2020 07:29:34 GMT

Hi,

I used the sdk_config.h file you sent me, but it didn't output any logs.

My development environment

SEGGER Embedded Studio for ARM Release 4.52 Build 2020033100.41808 macOS x64
nRF5_SDK_16.0.0_98a08e2

Is it a problem with the SDK or IDE version?

RE: I want to transfer data fast with SAADC and BLE UART

Vidar Berg — Fri, 11 Sep 2020 10:08:04 GMT

Hi,

Good to hear that it improved the performance. But I'm suprised logging didn't work. Did you try to use my project with my sdk_config.h file?

RE: I want to transfer data fast with SAADC and BLE UART

kurotaky — Fri, 11 Sep 2020 09:40:37 GMT

Hi,

The result of NRF_LOG_INFO() doesn't output to the debug terminal, but I think the BLE communication transfer is faster. Thank you.

RE: I want to transfer data fast with SAADC and BLE UART

Vidar Berg — Wed, 09 Sep 2020 07:05:28 GMT

Hi,

Thank you for the clarification. It make sense that you get error 5 if you weren't able to establish the connection in the first place. Anyway, I tried your project here, and it seems like all the slow printf's is causing your program to spend too much time inside the ISR and thus blocking other parts of your program. Please try my modified project attached below and see if works better.

Modified project using nrf logger:

devzone.nordicsemi.com/.../ble_5F00_app_5F00_template_5F00_nrf_5F00_logging.zip

Output with nrf logging instead of printf's:

[quote user="kurotaky"]I would like to send SAADC values to nRF Connect with a 100 or 50 msec cycle.
Is there a problem with ble_nus_data_send() in saadc_callback()? Or do I need to set some environment variables? It seems to be slowing down in the bluetooth communication part.[/quote]

I don't think you should have any problem with sending the measurements from the SAADC callback at this rate. Although you could reduce the overhead by putting multiple SAADC readings in each notifcation packet.

RE: I want to transfer data fast with SAADC and BLE UART

kurotaky — Wed, 09 Sep 2020 00:29:47 GMT

Hi, I have two problems

1.
If SAADC_SAMPLE_RATE is shortened from 400 ms to 100 ms and 50 ms, the connection will not be possible. In this case, Error 5 is returned.
github.com/.../main.c

I would like to send SAADC values to nRF Connect with a 100 or 50 msec cycle.
Is there a problem with ble_nus_data_send() in saadc_callback()? Or do I need to set some environment variables? It seems to be slowing down in the bluetooth communication part.

I think it's taking 400msec.

Source code

https://github.com/kurotaky-sandbox/ble_app_template/blob/master/main.c

RE: I want to transfer data fast with SAADC and BLE UART

Vidar Berg — Tue, 08 Sep 2020 07:43:37 GMT

Hello,

Do you get any notifications through at the 100 ms sampling interval, and is "Disconnected." printed in your log before you get the error? Error 5 usually means the 'conn_handle' is invalid.

RE: I want to transfer data fast with SAADC and BLE UART

kurotaky — Mon, 07 Sep 2020 10:13:54 GMT

Thanks, awneil.

I set SAADC_SAMPLE_RATE 400 and it worked. BLE_NUS_EVT_COMM_STARTED and can connect to the iPhone.

I want to send SAADC data in BLE with a value less than 100ms,
but when SAADC_SAMPLE_RATE is set to 100, I can no longer connect to nRF Connect apps(iPhone).


err_code is 5 (The value returned by ble_nus_data_send).

regards,
Yuta

RE: I want to transfer data fast with SAADC and BLE UART

awneil — Mon, 07 Sep 2020 09:37:17 GMT

[quote userid="93292" url="~/f/nordic-q-a/65645/i-want-to-transfer-data-fast-with-saadc-and-ble-uart"] I'm having trouble transferring the data or getting an error when sending several times[/quote]

So what "trouble", exactly, are you having?

And what "error" do you get?

What debugging have you done to find the problem? eg, does it work at slower speeds?