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Andrew Kesterson
2026-06-04 19:00:24 -04:00
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05-photoresistors/README.md
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@@ -80,3 +80,8 @@ $$ Vout = 5 * \frac{10k}{10k + 10k} $$
... Or `Vout = 2.5v`. For fun, stick different value resistors in the R1 and R2 place. Probe it, and see how the value at the tap changes. And THAT is why potentiometers act like a voltage divider - because by turning the dial, you can change the sweep of the wiper, which changes the size of the resistive material on both sides of the wiper, which changes the resistance value of the material on both sides of the wiper, changing the resistance values of the two sides of the potentiometer!
This is also why the tutorial circuit is wired up the way it is. Because it's using a 10k resistor as the first half, and the photoresistor, as the second half, of a voltage divider. As the photoresistor reacts to light, the resistance value of the photoresistor changes, which changes the R2 value in the voltage divider, which varies the value being shown on the tap at the GPIO pin which is processed by the ADC on the ESP32.
<center>
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