When experimenting with low power, mesh networked IoT nodes outdoors there a bunch of power features that would make it easier to quickly prototype and deploy these nodes.
- Solar power input.
- 18650 battery.
- Zero drain battery voltage monitoring.
So the solution here is going to totally be a standing on the shoulders of giants job. Most of the hard work has already been done by Adafruit. This project builds on a couple of different Adafruit projects and I acknowledge, credit and thank Adafruit for their awesome products and engineering.
So the perfect form factor for a prototyping Solar/battery IoT nodes is the feather platform. You can then choose from a whole range of micro’s and different radio configurations.
Adafruit have already done the hard work and have a Solar Lithium Ion Battery charger.
What I’m planning on doing for version 1 is build a PCB that is a FeatherWing that integrates the Adafruit solar lithium ion battery charger module, onboard 18650 battery holder, zero drain battery voltage monitoring circuit and a power switch (that switches the enable pin on the feather).
With mounting holes and the on board battery holder it will make for a very neat and easy to ingress protect/mount/enclose IoT node.