Useless Robots

Robotics, Electronics, and Embedded Systems


2-bit transistor robot

Alice is a robot programmed in transistors—transistors and resistors soldered together to form logic gates and then linked up into a finite state machine. A finite state machine (FSM) is a machine/circuit that has a finite number of states and can change its state based on inputs it receives. Each state can cause the machine to have different outputs. In the case of Alice, there is a state for going forward, backing up, turning back to the right, and turning back to the left. The logic circuits within Alice determine how the FSM will transition between states. If Alice sees an obstacle, Alice will transition into the backup state. While in this state Alice will choose randomly between turning back right or left by looking at the input of a ring oscillator (basically doing an electronic coin flip). After turning, Alice then goes forward again.

Start – CompletionFebruary 2018-April 2018
Languages & Technologies UsedTransistors, Resistors, Solder, Batteries, Motors, Infrared Sensors


As soon as I discovered that you could basically program stuff using only transistors, I set out to do just that.

Development & Challenges

See Hackaday!


It’s a ball of messy wire!