Step 1: Program the At tiny 45
I used an Arduino Nano to program the At tiny 45 it was easy to setup and worked great. The code shown reads the analog input and uses that information to figure out how many led’s should be on if any. The values at which each led lights up are dependent on the antenna, its resistance to ground, and the attiny’s input sensitivity. These values will have to changed in the code to best match your personal setup. Sensitivity is adjusted by increasing or decreasing the resistance to ground on the antenna and by changing the led turn on values.
Step 2: The Circuit
Start by connecting one of the At tiny 45’s analog inputs to the antenna then ground it using four 1 mega ohm resistors in series, after that wire the remaining outputs to light four led’s. I used a solid copper wire for the antenna and wrapped it around a marker to get the spring like coil.
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