BAbout this program
Pedro is a fully open-source, 3D-printable educational robot arm designed for STEM classrooms and makers who want to learn robotics from scratch. With only four printable parts, four mini servo motors, and tool-free snap-together assembly, Pedro can be built and operational in under 10 minutes.Design Philosophy
Source: https://github.com/mattions/pedro
Pedro is intentionally minimal. The entire structure consists of four 3D-printed components — BASE, ARM, GEAR, and SERVO bracket — that snap and gear together without screws or adhesive. This makes it ideal for workshops where dozens of students can assemble their own robot simultaneously. All parts print in under 2 hours on any FDM printer at 0.2mm layer height in PLA or ABS.
Electronics
Pedro is powered by a custom Arduino-compatible controller board called the Pedro Board, which integrates four servo outputs, an nRF24L01 radio module for wireless control, an HC-05 Bluetooth module for smartphone connectivity, and an ESP8266 for WiFi and IoT integration. Power comes from a 7.4V LiPo battery rechargeable via USB.
Control Modes
Pedro supports five control modes: Manual (serial/USB from a PC), Radio (nRF24L01 remote), Bluetooth (smartphone app), Replay (execute recorded sequences), and Record (capture and store movement sequences). The firmware is built on the Arduino platform and is fully open source under Apache 2.0 in the PedroRobot repository.
Community
Pedro is used in over 70 schools and educational workshops across France and internationally. The project ecosystem includes Pedro Board (PCB gerbers + schematics), PedroRobot (Arduino firmware), and PedroSTEM (complete lesson plans and activities). All repositories are published under Apache 2.0 by Almoutazar Saandi.
🖨 Print Files (14)
BASE.stl
SERVO.stl
ARM.stl
GEAR.stl
GEAR.stl
Base_Servo.stl
Required Hardware
Source: https://hackaday.io/project/26119-pedro-robot-an-open-source-robotic-arm (Moon Robotic / Almoutazar Saandi, 2017 Hackaday Prize)
GitHub: https://github.com/mattions/pedro · 3D files: https://www.thingiverse.com/thing:2465385
Pedro is a 4-axis open-source 3D-printed educational robot arm. The official BOM has two layers: the Pedro Board (custom Arduino-compatible PCB built around an ATmega328P) and the mechanical kit (four SG90 servos + printed parts). The Pedro Board can be substituted with an Arduino Uno/Nano if you don't want to fabricate the custom PCB — pin mapping is documented below.
Servos & Motion
| Qty | Part | Notes |
|---|---|---|
| 4 | Tower Pro SG90 9g micro servo | Base, shoulder, elbow, gripper. Official Pedro spec. |
Pedro Board — Microcontroller
| Qty | Part | Notes |
|---|---|---|
| 1 | ATmega328P DIP-28 microcontroller | Pre-flashed with Arduino bootloader, or substitute an Arduino Uno/Nano |
| 1 | 16 MHz crystal oscillator | Clock for ATmega328P |
| 2 | 22 pF ceramic capacitor | Crystal load caps |
| 1 | 10 µF electrolytic capacitor | Power decoupling |