Krabos - walking robot

In this tutorial I will describe construction of a six-leg walking robot in enough detail so that everyone with basic experience with electronics and computer programming can build his own robot for cost less than $70.

 Krabos - walking robot

The aim was to create walking robot which is more attractive than wheeled machines and its programming offers interesting problems to solve not only on the higher level of autonomous operation but also on the low level of microcontroller programming - which is useful for people who want to learn how to program microcontrollers and have some fun along the way. The building cost should be very low, and that’s why design with only three servos is used. There are designs which use two or even three servos per leg, which gives the robot more maneuverability, but makes it quite expensive. The 3-servo walker described here is a good compromise between price and performance. It can not only walk forward but also turn and walk backward.

The robot is able of autonomous operation controlled by its microcontroller or it may be directly commanded from a personal computer which makes it possible to experiment with even very complicated movement algorithms.

Described robot is built from a scratch, from “raw” materials and electronic parts.

The mechanical construction is easy; it does not require any electric tools except a small drill. The electronic is also simple using single printed circuit board which can be drawn by hand. It would be even possible to make it on a bread board. All that is needed is a soldering iron and little experience with this kind of work.


The communication program for PC is written in C# using Microsoft Visual C# Express development environment. If you are not familiar with C# you will still be able to play with the robot and write simple algorithms. 


Both the MCU programming and PC programming are interesting areas which one may sooner or later find himself studying in a less interesting way, so why not start now with this project? Building your own robot is not as difficult as it may seem and it will bring you great satisfaction when you see it’s really walking. Just try it!


Here is overview of Krabos' features:

  • Walking robot with six legs, powered by 3 servos

  • Control board with Atmel Tiny 2313 microcontroller (MCU)

  • Connection to PC through serial interface. Possibility to control the robot directly from PC or let it run autonomously controlled by the MCU

  • Total cost about $70

  • Building time about 15 hours

The tutorial is divided into folowing parts: