Tools & Accessories
LDR Module (Light Sensor)
৳130
Light-dependent resistor on a comparator board, giving an analog brightness level and an adjustable digital day/night trigger.
The LDR's resistance falls as light rises — roughly 10–20 kΩ in normal room light and up to about 1 MΩ in darkness — and the board turns that into signals a microcontroller can read.
What you can build
- Street lights and night lamps that switch on automatically
- Brightness-following displays and backlights
- Beam-break counters and simple light alarms
Not sure it will work? Test your circuit free in Tekko Sim — on your phone, in Bangla or English.
| Category | Tools & Accessories |
| Model no. | LDR / GL5528 |
| Availability | In stock |
| In stock | 5 pcs |
| Delivery | Cash on Delivery, nationwide Bangladesh |
| Sensor | GL5528 light-dependent resistor |
| Operating Voltage | 3.3–5V DC |
| Outputs | analog brightness level plus an adjustable digital trigger |
| Comparator | LM393 with an onboard potentiometer |
| Light Resistance | roughly 10–20 kΩ at 10 lux |
| Dark Resistance | around 1 MΩ |
Questions about the LDR Module (Light Sensor)
Analog or digital output — which should I use?
Digital for a simple on-at-dusk switch; set the threshold with the potentiometer. Analog if you want the actual brightness level, for example to dim a display in proportion to room light.
Can it measure light in lux?
Not accurately. An LDR's response is non-linear and varies from part to part, so it is good for relative brightness but not for a calibrated figure. For real lux use a BH1750 or TSL2561.
Why does the reading drift during the day?
LDRs respond slowly and also react to the colour of the light, so daylight and lamplight of the same apparent brightness give different readings. Add hysteresis in software so the output does not chatter around the threshold at dusk.
More in Tools & Accessories
All tools & accessories →
