How to run a combined projects of SAADC and BLE_APP_HRS

[Parzival]

Dear all,

sorry for asking a very beginner's question but I'm really a beginner and want to understand what I'm doing :)

What I have:

• nrf52 DK
• nrf SDK11.0.0
• GCC with Eclipse
• PCA10040

What I want to do: I want to read out an analog input channel of the nrf52 DK and transmit the data to my IPhone (nrf Toolbox app) via BLE

What I did:

I used the SAADC sample code and the BLE_APP_HRS code. I tried to combine both projects. I included all .c and .h and all the functions in main.c of the SAADC sample into the BLE_APP_HRS makefile and main.c. Everything works and I don't get errors.

Problem: If I remove saadc_sampling_event_init(); and saadc_sampling_event_enable(); the LED1 of nrf52 DK is blinking and if I connect it with my phone it constantly shines. However then I cannot read the analog input. And if I put those lines again into main.c of the BLE_APP_HRS the LED1 is not even blinking and I cannot connect to the device as its name doesn't appear.

Hope that you can help me.

THX!

[Jørgen Holmefjord]

Hi,

You can find an example of the SAADC combined with the BLE UART example for SDK 11 in this GitHub repository. The SAADC is sampled, and the transmitted over BLE using the Nordic UART service (NUS). Did you want to transfer the sample over the heart rate service?

Note that the SAADC example in the SDK use TIMER0 to do the sampling. This timer instance is blocked by the softdevice when it is enabled. This will cause an error, and the default error handler will restart the device. You will have to use another timer instance for sampling.

Best regards,

Jørgen

[dongsung kim]

so, what can i use another timer instance for sampling? you mean the PPI drv? 

[dongsung kim]

i'm looking for that SAADC combined with the BLE HR sensor solution. 

so, i refer to the ble_app_proximity in the SDK. is that correctly solution?

i guess, if SAADC code in the SDK is combined with current ble_app_hrs, some timer error will be occurred.

i don't know how can i make timer instance for SAADC sampling

[Jørgen Holmefjord]

You can use any timers not used by the softdevice or other parts of your application. You can also use RTC or application timer library to sample SAADC, or trigger sampling manually. If you are having specific issues, please post a new question where you described your issue in detail.