Although I am an experienced software engineer, I am still quite a novice in electrical engineering. So please bare with me in explaining my requirements:
I have a small garden in my backyard and I would like to add a soil moisture sensor in the ground, connecting it with an RFM95W as a LoRaWAN node.
The sensor will likely take a measurement every 6 to 9 hours, and go to sleep to save battery life.
Whichever board I use will connect to another RFM95W that's a LoraWAN gateway hooked up to an Rpi inside my home, so that I can forward the data to a local LoRa Server (MQTT).
Eventually I hope to get to a point where the board will open a water source when the soil is dry (over PWM motor control -- which I have done with the Pi over bare metal before).
Secondly I hope to run some very basic deep learning on the data, directly on the MCU as discussed in this blog post
Therefore, choosing an ARM MCU seems like a good fit. There's the Cortex-M0 and its successor the M0+.
The problem I have in making the decision between them is based on the following:
1) The M0+ is marketed as a very power efficient MCU and therefore can work well with a battery for a long time
Therefore I am wondering if the low power consumption is the case for the difference in price and if I can still get the same performance; i.e. long battery life, from the