Not all signal generators have to be complex devices. Sometimes you just need a signal generator with few features. This Attiny25 based signal generator does just that. It can output square, sine and triangle waves simultaneously from 1Hz up to 40kHz. Resolution isn’t brilliant – just 6 bits.
Signal frequency can be adjusted in 256 steps what means that from 1Hz to 40kHz it ups exponentially. Despite its poor signal quality and lack of fine control signal generator may find its purpose in many uses.