If you’re lucky to be able to design with a CM4 in mind and an external ... your WiFi antenna. [Avian]’s been testing things like these every now and then – a month ago, his ESP8266 GPIO ...

By taking a 3D printed design intended to attach a TP4056 module to the end of an 18650 cell and combining it with an ESP8266 ... the built-in PCB antenna, but hacking on an external can get ...