As an slight extension of my project, I am trying to see if I can improve connectivity resilence by using a dual-SIM approach. Dual-SIM phones (or Tri-SIM, quad-SIM phones) are quite popular in many ...
Okay, the title sounds odd, I'll admit. I need my project to work without power. That is, a complete power failure may happen, and no additional power (such as a battery or supercap) is available ...
I have two mains power inputs (in case one fails, the other is likely to still work), but the device only has one power supply, so I decided to use a relay to switch between the inputs (the device ...