Useless machine for Lego WeDo 2.0 45300 instruction (Build Wedo Robots — a series of instructions for assembling robots with wedo 45300 Book 24) - Kindle edition by Evdokein, Vladimir, Gergert, Vyacheslav. Children Kindle eBooks @ Amazon.com.
Lego Technique: LEGO Technic useless machine
The intelligent rebounced RCX switch | Hackaday.io