Breadboard Prototype

March 8, 2018

Next I wanted to put the whole circuit together, running the solenoid off the Tiny85 with a potentiometer controlling tempo and a switch to turn the whole thing off. In a uni workshop we learned a more flexible way of programming the ATTiny85, which used an Arduino as the In-circuit Serial Programmer instead of the Digispark. This will allow me to upload the program onto many chips just by plugging them into the breadboard one at a time.

Following the tutorials on HiLowTech [1, 2] I got the basic LED blink program running via this method.

I then combined this with the basic 5V solenoid circuit [3], and loaded the Arduino code I wrote previously to get the solenoid tapping out rhythms.

Then I added a switch and potentiometer, adjusting the code slightly to have the value read from the potentiometer control the tempo of the rhythm [4]. At this point I was also able to disconnect the Arduino and just use it as a power source.

With the basic circuit in place, I now need to:

Do some research and experimentation into battery power. First I’m going to try some lithium coin batteries and get a sense of how much life I might get from them. Another option to explore is rechargeable batteries.
Try out some different solenoids, switches and potentiometers, obtaining a better understanding of the trade-offs between price and aesthetics. Which leads me onto:
Design some housing for the circuit. Making decisions about this will depend on drawing together some of the conceptual threads motivating this project to give it a guiding aesthetic.

Notes