Limitbit Tech's Raspberry Pi-Powered Companion Bot, Doly, Crowdfunds Soon — or Build Your Own Now

Limitbit Tech is preparing to launch a crowdfunding campaign for a compact companion robot, powered by a Raspberry Pi Compute Module 4 — and has published a 3D-printable kit version right here on Hackster.io for those willing to do everything themselves.

"Doly is a unique and innovative 3D-printable companion robot," claims Limitbit founder and chief executive officer Levent Erenler of his company's creation. "What sets Doly apart from other robots in the market is that it is based on open design and open hardware. This means that users have the freedom to customize and modify the robot according to their needs and preferences."

Originally, Doly was to be powered by a custom embedded Linux system — but, following feedback on early designs, Erenler took the project in a different direction and pivoted to the Raspberry Pi Compute Module 4 (CM4) system-on-module (SOM). "This updated design provides more flexibility," Erenler says, "allowing you to upgrade your hardware if you need more RAM or storage for complex projects. Plus, you now have access to hardware with 6 GPIO, 2 servos, UART, I2C and USB. I expected the upgrade to take 4 months, but it ended up taking 6 months."

Exact specifications, then, will depend on the model of CM4 installed within Doly's body — but all models will have a Broadcom BCM2711 system-on-chip with quad-core Arm Cortex-A72 running at 1.5GHz, up to 8GB of RAM, and a wealth of sensors including an eight-megapixel Sony IMX219-based camera module, two touch sensors, a six-axis inertial measurement unit (IMU), two time-of-flight (TOF) distance sensors, four infrared edge sensors, and two microphones, plus six general-purpose input/output (GPIO) pins and a single Qwiic port for further expansion.

For outputs, the compact robot body includes two speakers, two servo motors, two DC motors with encoders, two LCD displays arranged as animated "eyes," and two RGB LEDs, along with two spare servo outputs for expansion. On the software side, the robot comes with the promise of on-device machine learning (ML) capabilities include face, speech, and object recognition, autonomous pathfinding, and a Google Blockly-based low-code programming environment for customization.

"Because Doly is open-source," Erenler adds, "it is easier for users to collaborate and share their ideas with each other. This means that as the Doly community grows, the robot will continue to improve and evolve. By sharing knowledge and working together, the possibilities for Doly’s development are endless."

More information on Doly's current capabilities are available on the official website; files and instructions for building your own are available here on Hackster.io. The crowdfunding campaign for kit form and fully-assembled Doly robots, meanwhile, will launch soon on Kickstarter, Erenler has confirmed.