MuTech RoboticsLearning Hub
Kids OK with adultESP32Level 3/3

DOG-12 Robot Dog

A 14-servo robot dog that walks, sits, gives a paw, dances and does a little pounce hop.

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DOG-12 Robot Dog
Kids OK, with an adult

DIY project. Children must build this only with an adult (16+ years) beside them at all times. Not suitable for children under 8 years.

An adult handles the Li-ion pack. Never power the servos from the ESP32 or USB 5 V: the board browns out and the legs go limp.

Strictly follow the description given with this video.

Video

How it works

  1. Each leg has 3 servos (side, hip, knee); the knee is driven by a push-rod from a servo up in the upper leg.
  2. A 16-channel servo driver gives all 14 servos their signals over I2C.
  3. The tilt sensor keeps it balanced; the ultrasonic snout sees obstacles; the small screen shows its eyes.
  4. A 7.4 V pack feeds a 6 V 10 A converter for the servos and a 5 V converter for the ESP32.

Parts you need

  • ESP32 dev board₹518× 1Buy
  • 16-channel servo driver (I2C)₹345× 1Buy
  • 14× 20 kg·cm metal-gear servos (6 V)₹1,322× 14Buy
  • IMU tilt sensor₹172× 1Buy
  • HC-SR04 ultrasonic sensor₹80× 1Buy
  • 2S Li-ion pack 7.4 V + switch + 15 A fuse× 1Buy
  • 6 V 10 A converter (servo bus)₹126× 1Buy
  • 5 V 3 A converter (ESP32)₹518× 1Buy
Kit for this projectPrice on request
Get the kit

Wiring

Both converter inputsBattery+ (switch, 15 A fuse)Servo bus + / GND bus6 V converterout5V converter outVESP32VIN / GND3V3GNDD21D22D27DriverVCCGNDSDASCLCH0–CH13Same I2C bus,3V3IMU + displayUltrasonicVCCTRIGECHOGND(1 kΩ, D26, 2 kΩ D26)Servo signals
PowerGroundSignal
#FromConnect to
1 PowerBattery + → switch → 15 A fuseBoth converter inputs
2 Power6 V converter outServo bus + / GND bus
3 Power5 V converter outESP32 VIN / GND
4 PowerDriver VCCESP32 3V3
5 GroundDriver GNDESP32 GND
6 SignalDriver SDAESP32 D21
7 SignalDriver SCLESP32 D22
8 PowerIMU + displaySame I2C bus, 3V3
9 PowerUltrasonic VCC5 V
10 SignalUltrasonic TRIGESP32 D27
11 SignalUltrasonic ECHO1 kΩ → D26, 2 kΩ D26 → GND
12 SignalServo signalsDriver CH0–CH13
13 PowerServo + / −6 V bus / GND bus (not through the driver)
14 SignalChannel mapLegs FL 0–2, FR 3–5, RL 6–8, RR 9–11; head 12, tail 13
A wiring step from the video
A wiring step from the video

3D print files

  • upper_leg.stl ×4Concept-level; test-fit firstDownload
  • lower_leg.stl ×4Concept-level; test-fit firstDownload
  • hip_bracket.stl ×4Concept-level; test-fit firstDownload
  • body_frame_half.stl ×2 (mirror one)Concept-level; test-fit firstDownload

Code

Get the code