520 Pi Snake
520 : Pi Snake
- Author: htfab
- Description: Voltage divider that generates π volts
- GitHub repository
- Clock: 0 Hz
How it works
The blue circle has unit radius and therefore an area of π units. We can enclose it by a polygon with exactly 3.3 units of area, adding the parts marked red. Using precision resistors that meander through the blue and red areas respectively we can construct a voltage divider that subdivides the the 3.3 V power and ground rails to achieve a π V output.
How to test
Measure the voltage between the single analog output pin and ground. It should read approximately π volts.
External hardware
Multimeter or other test equipment
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | |||
| 1 | |||
| 2 | |||
| 3 | |||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 |
Analog pins
ua | PCB Pin | Internal index | Description |
|---|---|---|---|
| 0 | B0 | 6 | voltage output |