A timer 555 based drum machine
Like in the VCO Tutorial, we are going to use a 555 timer to design a synthesizer but now it will work as a drum machine.
We have selected the resistors and capacitors values to get a low frequency of oscillation, from 1 beat every 2 seconds to close to 180 beats per minute.
Schematic:
The schematic shows a NE555 timer in an aestable mode.
We are able to control the beat rate connecting a potentiometer at JP1 pin header.
We have two more pin headers:
- The one on the top is for output ("OUT" Label). Pin 1 is connected to +5 volts, pin 2 is the output signal, pins 3 and 4 are connected to ground.
- The one that is below is for input ("IN" Label). Pin 1 is connected to +5 volts, 2 is isolated, 3 and 4 are connected to ground.
Photos:
NOTE: begin with r1=1k, C1=10uF
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