Review on HiLetgo Internet Development Wireless Micropython Networking Products by Ian Patilla

WLAN and reasonable computing power on a tiny (cheap) board. The cheapest way to get a WiFi enabled device that I know of. A turning point for amateur IoT in the home. For example, it can provide access to a web server or HomeKit service on the network, allowing you to plug it into a USB power source and control garage doors, environmental sensors, buttons, locks, relays, etc. You can update the OTA firmware. also very cool. I'm using an Arduino, but you can program it in many other ways. The only downside to these little guys is that the number of gpios you can actually use is very limited - much less than the generous-looking number listed. The reason for this is that most GPIO pins need to be high or low at boot to select normal operation. (Using these pins for gpio results in unreliable startup behavior, such as starting in random mode after a power failure). Also, not all pens have a built-in tensioner, which works but is inconvenient. I've forgotten the exact number of "spare" pens that can be used, but I'm currently using three, which is close to the maximum. You can use an i2c GPIO expander if that's a problem for you, but for a few extra bucks you can buy an ESP32, which is way more powerful in almost every way (including way more GPIO). One IoT device, typically a small handful of GPIOS, is all you need, so a few dollars off per unit is very welcome. (Did I mention they're insanely cheap?)