This article is about the one that looks like this (aka ESP-01). Flasher version is 2.3 Firmware version is 1.5 Firmware update might be necessary just after purchase. Without firmware update mine was not able to connect to Wi-fi routers (though they were able to find them) The current firmware available for this is… Continue reading ESP8266 ESP-01 – Part 1 – Flashing and AT commands