Now, when I say the word robotic arm, what comes to your mind? Well, you are probably thinking of digital control, motor drives, microcontrollers and a feedback loop. Well, if you ever owned an Amatron, you’ll know that a robotic arm is not all those things.
You’ll be surprised to hear that a guy built a servo-powered robotic arm without a microcontroller and with some interpretations. Trust me, no digital controller at all! The servos are operated by PWM signals, with a 1 ms pulse which rotates the shaft one way and with a 2 ms pulse rotating the shaft the other way. Venerable 555 is the cheap and best chip which can be easily configured as a timer.
Actually, the robotic arm is configured more like a Waldo with a master slave configuration. The second arm was built with pots at hinges, with the resistance of the pots controlling the signal output from a 556 dual timer chip. The project is a really amazing one built by Viswesh. It is a clever display of what can be done with a simple 555.