Blog excerpt: As fun as adding voltage boosters and/or voltage regulation and charge circuits is to our designs, sometimes it’s nice to just have everything done for us. We love the ESPxxxx/NodeMCU ecosystem: they’re cheap, they’re WiFi-enabled out-of-the-box, they’re small, and they’re usable in the Arduino ecosystem if that’s how you roll.
This is a NodeMCU-compatible board with a built-on 18650 battery holder and charge control circuit: it's already become one of our go-to boards when we need a battery-operated, low-IO WiFi-enabled part (a disturbingly-frequent ask), barely larger than the battery itself. Slick.
The brain is an ESP-WROOM-02 with a Silicon Labs CP2102 handling USB comms. An Advanced Monolithic Systems AMS1117 chip regulates the volts, charging is controlled with a Nanjing Extension Microelectronics TP5400.
You may need to install a driver for the Silicon Labs CP2102. Drivers are available on the Silicon Labs CP2102 Driver Downloads page for major environments.
In the blog post we detail how to get the device up and running in an Arduino environment. Future posts will use it for several IoT-style projects. Not having to worry about how to charge the battery, and providing mounting holes and a battery holder make this a great option.
At $10 a pop it's a great choice.