---
tags:
  - resource
created: 2025-07-20 12:21
---

## Summary

Resistors that change resistance based on the amount of light hitting them.
## Notes

Typically require an amplification circuit to interface to RPi.

## References

- [Photoresistors GL55-series comparison](https://ednieuw.home.xs4all.nl/Woordklok/LDR/GL55xxLDRs.html)
- https://www.handsontec.com/dataspecs/sensor/GL55-LDR.pdf
- [Getting Started With KY-037 Sound Sensor &amp; Raspberry Pi (P1) : 3 Steps - Instructables](https://www.instructables.com/Getting-Started-With-KY-037-Sound-Sensor-Raspberry)

![[GL55xx.pdf]]