In fact his latest design, an ESP8266 MQTT client ... but it didn’t have a display of its own; it just pushed the data out onto the network using MQTT. So he thought a companion device which ...

It’s based on the WarCollar Dope Scope, a tiny, portable device consisting of an off-the-shelf Chinese OLED display, an ESP8266 module ... ESP-based carrier board built for NodeMCU.