ESP-ROLL Is a Sphero-Like DIY Robot

Back in 2011, Orbotix launched their iconic Sphero robot. It was a really unique product, like a motorized hamster ball capable of rolling around according to its programming and with some basic sensors. Eventually, Orbotix took on Sphero as its company name and the Boulder, Colorado-based team still makes innovative robots — including the Mini, which is similar to the original Sphero. But building something is often more fun than buying it and if you like the Sphero concept, you’ll want to check out Max Imagination’s DIY ESP-ROLL.

The ESP-ROLL, like the Sphero, is essentially a self-balancing robot inside of a spherical shell that acts as a big wheel. Everything inside remains upright, while motors rotate the spherical shell in whatever direction is necessary to achieve the desired movement. In this case, the ESP-ROLL’s outer shell is transparent plastic and that made it possible for Max to add a camera to the electronics inside. There is even a tiny LED “ring light” in there to provide illumination for the camera.

As the name suggests, ESP-ROLL is designed around an ESP32 development board. Specifically, that is the Seeed Studio XIAO ESP32-S3 Sense, which is a very compact development board perfect for this task. That goes on a custom PCB that also hosts the other components, keeping everything tidy and secure.

Those other components include two 400 RPM micro geared DC motors, a DRV8833 dual H-bridge motor driver IC, battery and power management ICs, a lithium battery, and the camera module that comes with the XIAO ESP32-S3 Sense.

Of course, the most interesting thing about the ESP-ROLL is that spherical enclosure and the mechanical parts that make rolling around possible. The plastic sphere is actually an inexpensive ornament ball with a diameter of 100mm. Those come with a tab on top for attaching a string and that tab gets shaved off during the build process. The internal structure, designed in Autodesk Fusion 360, supports the components and has two wheels that rotate the outer shell. Weights help to keep that structure upright.

For the firmware, Max turned to the fantastic ESP32-CAM_MJPEG2SD created by user s60sc. That is extremely versatile and offers a lot of features, with a big emphasis on the camera. It can stream video in real-time or capture recordings, and can do so based on motion detection. For vehicles equipped with cameras, such as ESP-ROLL, it even allows for direct remote control of the vehicle’s motors over WiFi.

The resulting robot is, frankly, quite a bit more capable than the Sphero Mini in several respects and can be built for around the same price.