Sleep modes and Power consumption
A 2.4V Low Power OTAA Node
A KiCad PCB design
After building a cheap Atmega32 Arduino node as described in this story:
I decided to build a similar node based on the STM32F103C8T6 boards you can buy on Ebay and other sources for about $ 2.00.
for a board description.
The main advantages are:
- Much more space for your program (most boards have 128K flash even when advertised as 64K)
- 20K RAM
- High speed 32 bit ARM Cortex-M3 processor up to 72Mhz
The main disadvantages are higher power usage and a slightly larger board, but you can switch to lower speeds (8Mhz) and activate sleep modes to safe power when running on a battery or solar panel.
It will use 70μA while sleeping if you remove the power led and 12μA without the regulator.