Since our home's solar heating system needs a new controller I started designing a PCB with KiCad. I only need one SolBoard PCB for the solar heating  - the others will be control or demo boards. To that end I decided to add Arduino-like connectors for mass-production "shields". I plan to make using any STM8S controller in a LQFP32 package with 0.8mm pitch possible (from STM8S003K3T6C up to STM8S208KBT6C).

There are a number of design decisions to take, e.g. how to ensure that the power supply that will survive at least two decades.

There are now some things to decide:

• Which power supply module to use?
• How to design surge and overload protection?
• How to do milling for insulation?
• Which type of ESP8266 and nRF24L01 module to use (e.g. external or PCB antenna)

I would be happy to receive advice from the community!