Night light
The darker the light sensor reads, the brighter the LED — the brightness is an analogWrite duty cycle.
ldrled
Input
Photoresistor (LDR / CdS) with 10 kΩ divider
ldrAnalogChecklist
Why this support circuit is added
Light level via analogRead; the divider's top sits on the MCU's ADC rail.
Grounded in the catalog and golden patterns (real open-source circuits). Every auto-inserted part comes with a reason.
Support circuit added automatically1
Using this part in a project adds the circuit below, each element with its reason.
Pull-down resistor
2 → GND
An LDR alone produces no voltage; a 10 kΩ to GND forms the divider the ADC reads (Adafruit Photocells).
InterfaceAnalog
- Catalog id
- ldr
- Category
- Input
- Protocol
- Analog
- Logic level
- Unrestricted (uses the board rail)
Firmware detection0
No library reveals it — add it from the module checklist in your project.
Checklist partChecklist
Code alone can't reveal this part, so it lives on the module checklist. When added, it is bound to a free sketch pin with a matching direction.
Examples using this part
Run them in the browser, no login needed.
🔒
A remote changes fan speed
The IR remote's +/- drives a 12 V fan; it halves itself when the room goes dark.
ir_vs1838bldrload_mosfet