LED digit clock is a nixie-style clock with sound activated state machine. Eight LEDs are embedded in a machined block of acrylic. The block is braced against overturning moment with a short section of aluminum angle which is tapped with socket head bolts. Hot and ground are then routed from each LED to the arduino which also powers a small op amp and microphone.
Coding the clock necessitated a series of 10 code arrays to govern the physical outputs of 0 through 9. Other functions output the values of hour, minute and second counters to the physical array. The four states of the clock are a default counting state which blinks the entire array on the minute every minute. The second is a slightly more elaborate display on the hour. Left alone the clock will attempt to attract attention via these two states. If one asks the clock what time it is, the microphone / op amp assembly triggers a recognition sequence to indicate reaction to the audio stimuli. This state is immediately followed by outputting the actual time in sequential hour:minute format. The clock then returns to its default minute counting state. Will post code on another page.