This is my self balancing robot based on ESP8266, with an obstacle avoidance and remote control features, the entire code is written using arduino, also it has a responsive single web page where you can configure all needed parameters and control the robot remotely. The code and schematic can be found here https://github.com/Dave4675/Inverted-Pendulum
OTA is used so you can upload the firmware without connecting the usb cable https://arduino-esp8266.readthedocs.io/en/latest/ota_updates/readme.html
No arduino modules are used, just the ESP8266 in the version of wemos d1 mini

The bottom object is designed for be attached to a 400hundred bread board with no power supply lines

NOTE: glue gun is needed

The 9g holder is a remix of https://www.thingiverse.com/thing:1774451

The bottom is just a box with this https://www.thingiverse.com/thing:2848756 added

The battery used is a 2S 15C husban h502 one

The motors are n20 12V 200 or 300 RPM

video 1
https://youtu.be/Fy60T7QKW5E

video 2
https://youtu.be/FBLBiT4ejvY

I made the videos with my smartphone so I can't let you see how I remote control the robot, but actually it works like a kick, because the robot doesn't have speed encoders, if you have any suggestion for make this project better let me know.