DIY ESP8266 ESP-01 Programing / Test board

NodeMCU and other ESP8266 modules are starting to become very popular because they offer an embedded development platform with a CPU+RAM+Storage+WiFi all in one for (considerably) less than the price of an Arduino. There are a number of breadboard-friendly modules with all pins exposed (and more coming soon.) However, this post is about the breadboard-unfriendly ESP-01 module. It only has two GPIO pins (four if you include the TX & RX pins), but it’s smaller and most importantly, cheaper. US vendors tend to charge around $7, but if you don’t mind importing, they can be had for $3.50 or less. The biggest problem with the ESP-01 is that it’s annoying to wire up and program, so that’s what we’re solving today.”