AH Electronics

Great build! Looks very neat and cool.

Love the idea. I have just been getting into PCB etching, and I definitely want to try this one out.

Great work! Looks pretty simple to integrate into other Arduino projects as well.

Thank you :) . The electrical part is optional, just using a switch and power jack could be enough too.

Thank you! In step 5 I linked an Youtube video where someone explained the circuit really thoroughly and around the 5 minute mark it should explain it. But I hope my explanation helps somewhat.The Duty Cycle is based on the time on and time off of the output. This is dependent on the charging and discharging time of the Capacitor C1. As you can see in the image, the diode in addition to the potentiometer creates two separate paths with different resistances for the C1 to charge and discharge. Since we used the middle point of the potentiometer to connect to C1, increasing the resistance of one path decreases the resistance of the other path. So overall the charging+discharging time remains the same, so frequency remains the same, while the duty cycle becomes adjustable.