Anonymous
Mar 27, 2026
Rating: 4/5
Good sensitivity, needs calibration
The module is sensitive and picks up motion well. I had to tweak the potentiometers a bit to stop false triggers from my ceiling fan, but once set, it works great.
Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Model Number | HC-SR501 |
| Operating Voltage | DC 4.5V - 20V |
| Detection Angle | < 120 degrees cone angle |
| Detection Distance | 3 to 7 meters (adjustable) |
| Trigger Mode | L (Low) and H (High) selectable via jumper |
| Delay Time | 5s to 300s (adjustable potentiometer) |
| Blocking Time | 2.5s (default, adjustable) |
| Output Signal | 3.3V High level / 0V Low level |
| Dimensions | 32mm x 24mm |
| Operating Temperature | -15°C to +70°C |
Anonymous
Mar 27, 2026
Rating: 4/5
Good sensitivity, needs calibration
The module is sensitive and picks up motion well. I had to tweak the potentiometers a bit to stop false triggers from my ceiling fan, but once set, it works great.
Anonymous
Mar 25, 2026
Rating: 5/5
Excellent for learning electronics
Bought this for a university project on smart lighting. The documentation online is plentiful, and the module itself is robust. Highly recommended for beginners.
Anonymous
Mar 22, 2026
Rating: 5/5
Best PIR sensor in this price range
I have tried several brands, and this HC-SR501 offers the best stability. The warm-up time is reasonable, and the output signal is clean for microcontrollers.
Anonymous
Mar 18, 2026
Rating: 4/5
Solid performance
Works as advertised. The L/H trigger mode selection is a nice feature that adds flexibility. Only giving 4 stars because the pins were slightly bent upon arrival, but easily fixed.
Anonymous
Mar 17, 2026
Rating: 5/5
Perfect for Arduino projects
This sensor works flawlessly with my Arduino Uno. The detection range is accurate, and the delay time adjustment is very smooth. Great value for money.
Anonymous
Mar 06, 2026
Rating: 5/5
Reliable and compact
Small footprint makes it easy to hide in enclosures. I've used three of these for different rooms, and they all perform consistently. No issues so far.
Q: Does this come with headers pre-soldered?
A: Typically, these modules are shipped with unsoldered pins to allow for flexible mounting options. You will need to solder the 3-pin header yourself.
Q: Is this compatible with Raspberry Pi GPIO?
A: Yes, it is compatible. Since the output is 3.3V high, it connects directly to Raspberry Pi GPIO pins without needing a level shifter. Just ensure you connect VCC to 5V and GND to Ground.
Q: Can this sensor detect motion through glass?
A: No, standard PIR sensors like the HC-SR501 cannot detect infrared radiation through glass. It requires a direct line of sight or an open window.
Q: How do I adjust the detection distance?
A: There is a potentiometer labeled 'Distance' on the board. Turn it clockwise to increase the range and counter-clockwise to decrease it. Test in your specific environment for best results.
Q: What is the maximum current this module can handle?
A: The output pin is designed for logic signals (approx. 3.3V) and should not be used to drive high-current loads directly. Please use a relay or transistor to control devices like lamps or motors.