How to build junkbots: Old toys In a previous blog entry the idea of using drinks can and an unbalanced motor was discussed. but what else have the projects participants t... How to build junkbots: Drinks can, unbalanced motor The junkbots project has now being running for 18 months in Northamptonshire, UK. But how have the junkbots being built? A video produced by... How to build junkbots: Wheels don’t always work well Back to the main approach, simplest way and probably the quickest:- A body (drinks can and drinks bottles usually) and an unbalanced motor -... Huxlow Pt 2: Lego Robots The second half (programming lego robots) on the junkbots project has been carried out at Huxlow Science College on 28th February 2011. ... Toys from trash Arvind Gupta has produced a lot of work on turning junk into toys that aim to demonstrate the engineering ideas in an very interesting (wel... Brooke Weston Event Students at Brooke Weston School, Corby have been working with the University of N…
Three approaches to control it will be considered here: - via Raspberry Pi; - via Micro:Bit -via Crumble controller
1. Raspberry Pi based
In this Raspberry Pi based Junkbot design a combination of Python and Pimoroni's Explorer HAT PRO are used to control it. Explorer HAT Pro is a good choice, it can control two motors with a library provided to simplify the programming. For this the Junkbot was the one shown above: a drinks can, pen, LEGO bits, motor and broken propellor.
Before the Explorer HAT can be used the library needs to be installed via the Terminal and the instructions below
curl get.pimoroni.com/explorerhat | bash Python code to control the junkbot is shown below.
import explorerhat from time import sleep def spin1(duration): explorerhat.motor.one.forward(100) sleep(duration) explorerhat.motor.one.stop() def spin2(duration): explorerhat.motor.one.backward(100) sleep(duration)
2. Micro:bit what about the recently released Micro:Bits; can …
I In an earlier post, I showed how you could build a Micro:Bit controlled Junkbot. In this post I want to show a modification to it, to use one Micro:Bit to control the junkbot controlled by another Micro:Bit. A nice feature of the Micro:Bit using micropython, is it can send and receive simple messages via radio - so here is my take on it.
The first problem is the Python editor available on https://www.microbit.co.uk/ does not seem to work with the radio API. One solution to this is to change to the mu editor.
Two pieces of code are needed.
Sending Code for the 'remote' control: Essentially it is set up to send two messages, via the built-in radio module, spinl or spinr depending on which button is pressed.
import radio from microbit import button_a, button_b
while True: if button_a.is_pressed(): radio.send('spinl') if button_b.is_pressed():