robotindex Petoi Bittle X V2
A palm-sized, 9-servo quadruped dog kit from Petoi, and the direct successor to the original Kickstarter-funded Bittle — same no-solder DIY build, upgraded to an ESP32-based "Biboard" controller with on-device voice control and native Raspberry Pi mounting. Runs Petoi's open-source OpenCat firmware, the same framework behind Petoi's cat-shaped Nybble Q and its newer, cheaper Quaddle line already in this catalog.
petoi.com/products/bittle-x →
Image: Petoi (official)
Specs
Battery
7.4V 1000mAh Li-ion~1 hour runtime, ~1.5 hour charge via USB
Weight
269–353 gassembled; varies by P1S alloy vs. P1L lite servos — petoi.com official specs
Dimensions
19.0 × 15.3 × 10.7 cmstanding — petoi.com official specs
Sensors
6-axis IMUMPU6050 or ICM42670; no camera included by default
Controller
Biboard (ESP32-WROOM-32D)520K SRAM, 16MB flash, Wi-Fi + Bluetooth built in
Frame
Engineering plastic
Joints
9 powered servos2 per leg + 1 neck; coreless "P1S" alloy or "P1L" lite
Voice Control
35+ commandson-device, no cloud dependency claimed; +10 custom
Expansion
4 Grove ports + Pi mountcamera/AI vision needs a separate module or user Raspberry Pi
Assembly
No soldering, ~40–90 minpre-assembled option sold at a premium
Reference Price
Bittle X V2 sells for $319 direct from Petoi in its base construction-kit configuration with lite plastic servos; alloy-servo and pre-assembled variants cost more. The separate AI Vision Module and robotic-arm attachment are priced and sold independently, so they aren't included in that base price.
Insights
Bittle X V2's firmware is genuinely open source under the MIT license (~5,300 GitHub stars), though its mechanical CAD/STL files have historically been distributed somewhat separately from the firmware repos rather than bundled into one unified open-hardware package. The "V2" designation reflects Petoi's current generation, distinguished mainly by the choice between lite plastic and alloy servos — the alloy option is required to physically support the optional robotic-arm attachment.
Firmware & Community
PetoiCamp/OpenCatEsp32-Quadruped-Robot
Runs OpenCatEsp32, the ESP32/BiBoard branch of Petoi's OpenCat quadruped framework.
Verified against Petoi's official Bittle X V2 and original Bittle product/spec pages, its Quaddle and Nybble Q pages, its "About" and Kickstarter history pages, and its Research Spotlight page (self-reported, treated as a starting point); the PetoiCamp/OpenCat and OpenCatEsp32-Quadruped-Robot GitHub repositories and their license files; independent reviews from Tom's Hardware, BBC Science Focus, and The Gadgeteer; Hackster.io community projects for vision/ROS/voice add-ons; an independently published paper ("OpenMutt," SAGE 2025); and Petoi's own community forum threads on servo issues. Flagged as uncertain: the exact current bundling of mechanical CAD/STL files relative to the firmware repos (present but less centralized than the software); and whether Petoi's self-reported list of research institutions using Bittle has been independently verified beyond the company's own page.