RedBear BLE Nano 2

Question

I am admittedly a little lost here: 
 I am trying to utilize a RedBear BLE Nano 2 (nrf52832) to collect serial data from a sensor and send it to a raspberry pi every 15 minutes, using as little power as possible. 
 There are so many options when it comes to different softdevices, SDKs, IDEs, network topologies, protocols. I was hoping someone might point me in the right direction to most simply achieve my goal.

endnode · Accepted Answer

Sorry but what is the architecture exactly? Board with nRF52 will be receiving data over the air from sensors and feed RPI over serial interface or it will only collect data from sensors (over wires) and transport to RPI over the air? Is latter then how you enable RPI with BLE radio? 
 Anyway as soon as you clean up these things you will arrive to something like this: 
 
 Use the latest nRF5 SDK (v14.0.0 as of today) and S132 SoftDevice (= Nordic BLE stack, V5.0.0 as of today). 
 If you want to use connection link based solution (reliable transport but probably little bit more power hungry on nRF52 side) then look at Nordic BLE UART Service examples ( nRF5_SDK_14.0.0_3bcc1f7\examples\ble_peripheral\ble_app_uart and nRF5_SDK_14.0.0_3bcc1f7\examples\ble_central\ble_app_uart_c ). 
 If you are fine to have not 100% reliable link but the lowest power consumption possible (only on sensor side, on RPI side it will go up by several levels compared to previous architecture) then go with simple broadcaster (beacon) and observer (scanner) examples (e.g. nRF5_SDK_14.0.0_3bcc1f7\examples\ble_peripheral\ble_app_beacon and any BLE Central project).