My first robot

My first robot – or rather my first robot that wasn’t a Lego Mindstorm robot. We have build Lego sumo bots at home and fought, trying to push each other out of a circle on the floor. It was great fun (even though I got hammered by my son) and hopefully we’ll keep doing that. But I wanted to try out several things that wasn’t possible with at Lego brick for a brain.

Mindstorms was replaced with a Raspberry Pi and the motors are Lego Power Systems. The motors are normally controlled with an IR remote, but if you can use a soldering iron it’s very cheap and easy to make a small IR transmitter for the Pi.

Robot #001 is a very small and compact robot with a lot of features;

  • Raspberry Pi 3b for a brain
  • Wifi
  • Motor control
  • Camera for livefeed
  • Speaker with Text-To-Speak so the robot can talk
  • Ultrasound sensor that can turn 180 degrees, 2m range

It can all be controlled from a web interface that has a livestream from the camera placed under the 2 Lego eyes.

I began trying to use the ultrasound sensor and QR codes on the walls to let the robot find its way from room to room. And then it got really really boring; The robot is too slow and often has problems getting over the doorsteps. It’s not much fun trying to program it to find its way to the kitchen when it takes ages just getting out of the office. So Robot #001 has already been retired.

Robot #002 is on the drawing board and the plan is simple:

  • Build it from cheap components (not Lego)
  • Must be able to drive indoors and outdoors.
  • Autonomously navigate indoor
  • Autonomously (and offline) be able to deliver a tin of beer to a neighbour on the road.

Except for the second point it’s a very ambitious plan. Actually with a small budget driving outside can also be hard, it takes a fair amount of power to drive through grass or loose stones. It also has to be fairly sturdy built so as not to get shaken to pieces on the cobble stones at the end of our road. If the robot will ever be able to deliver a beer to a neighbour is not so important as long as I’m having fun and learn something in the process. It’s not often I find time to play with robots, so it might be years before the robot is rolling down the road on its own.

The circuit board for connecting the servo and ultrasonic sensor is the smallest one I ever made.

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