Datalogger device with nRF52832

[Luis]

Hello,

We are developing an datalogger application that will push data to a server on the cloud using a cellphone app as intermediate. We are testing a BMD-350 DK board from Rigado that has a nRF52832 device inside. Basically the application will log some data from some sensors, save that data every 60 seconds and push trough bluetooth to the server when the cellphone is paired. Is there any example or suggestion to implement this application?

Regards,

[Jared]

Hi

I suggest that you that a look at our ble_app_uart example in the ble_peripheral folder in the SDK. The example shows how you push data to the Nordic toolbox application by using the ble_nus_data_send() function.

In addition you can use the application timer library to implement the timer functionality by using a repeated timer. See this guide for an explanation of the application timer library: https://devzone.nordicsemi.com/tutorials/b/software-development-kit/posts/application-timer-tutorial

[Luis]

Perfect, I could make it works. Second question. I am a bite new on this BLE world so I have a few questions. How can I reduce as maximum as possible the current consumption with this set up using the BLE? Should I change minimum and maximum connection interval? Considering the same payload of data and no real time needs. Shoul I add some slave latency?

Finally I would need that the app to reconnect automatically if the device goes off and on.. is this something possible? Anything to pay attention on the firmware or just on the cellphone app side?

Thank you!

[Jared]

Yes, extending both the slave latency and the connection interval will reduce the current consumption. You can use our online power profiler to estimate the current consumption of your BLE application: https://devzone.nordicsemi.com/power/

Additional strategies for minimizing the current consumption can be read here: https://devzone.nordicsemi.com/tutorials/b/hardware-and-layout/posts/nrf51-current-consumption-guide

The reconnection between the central and peripheral depends on if they have already been paired or not. In the UART example in the SDK they are reconnected automatically between the sleep cycles of nRF52 after they have already been paired. 

Cheers

Jared