The BPM Generator give you +5V pulses output with 20ms length, from 40 to 240 beats per minute. Controlled by a microprocessor. The BPM are displayed with three 7 segment LED. The speed is adjusted with an rotary encoder.
Most work is done by the microprocessor. The micro takes care of the output timing and the multiplexing off the display. All four outputs are independently buffered.