Merging of SPI code and ble_app_uart for nrf52840

[Rkidechaa]

HI,

I am developing weight scale with Bluetooth feature. I have already developed the code to get weight scale reading using SPI example.

Also tested ble_app_uart code individually and working fine.  Now i want to merge this code so that can send weight scale reading to nrf connect app using Bluetooth.

can you suggest me the step for how to merge both code and which file need to change?

Thank you,

Rahul Kidecha

[Marjeris Romero]

Hi Rahul,

Have you seen this guide for merging two examples together in nRF5 SDK: https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/merging-two-ble-examples-together ?

Best regards,

Marjeris

[Rkidechaa]

Hi,

I referred to the example shared by you and successfully merged the code. Also, i able to display the weight scale data on display and see the ble uart on nrf connect app.

I wanted to keep displaying the weight value under declared device name. I was trying to make changes in 
advertising_start(); function but was not able to display the value. 

The value i wanted to display is dynamic and i did not find where exactly i need to pass the value.

can you just tell me where exactly I need to make changes to display the weight scale value?

Thank You

Rahul Kidecha

[Rkidechaa]

Hi Romero,

I have successfully implement the merge and able to send the data over NUS.

I need to push nrf52840 to power saving mode and pull out when I put the load on weight scale.

Can you tell me which power saving mode should i use for this application? can I use SYSTEMOFF mode ?

Need to resume operation when we put load (weight) on it.

Thank you in advance.

Rahul Kidecha

[Marjeris Romero]

Hi Rahul,

There are multiple ways to do low power depending on what you want to implement. If you get a GPIO signal anytime someone steps on the weight scale you can use system OFF and a pin wake up. It will take some time to boot, but it could work depending on how quick the SPI peripheral will need to be ready to get the data from the scale.

Keep in mind that you cannot keep a BLE connection in system OFF though, so you will need also some time before you can connect again and read the scale data via BLE.

You could also use system ON IDLE for lower power consumption https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf52840%2Fpower.html&cp=4_0_0_4_2_3&anchor=unique_144597338

The Online Power Profile calculator will give you an idea of what IDLE current to spect depeding on the connection interval parameters and the transmit output power:
https://devzone.nordicsemi.com/nordic/power/

Best regards,

Marjeris