I will be using all of the following sensors at the same time on raspberry pi b+ model with 2Amp power supply.

1) DHT-11 Digital Temperature & Humidity Sensor for temperature and humidity measurement


3) Soil Hygrometer Humidity Detection Module Moisture Testing Sensor for soil moisture

4) HC-SR04 Ultrasonic Distance Sensor for measuring distance

I'm not sure whether the current will be enough for all the sensors and a wifi adopter connected to it. So can I supply current externally to HC-SR04 Ultrasonic Distance Sensor(needs 5V) and the HC-SR501 PYROELECTRIC INFRARED PIR MOTION SENSOR (needs 3.6V) through a DC power supply

2 Answers 2


Deja Vu.

A 2 amp power supply will be enough to power the Pi and sensors 1, 2, and 4.

It may be enough for 3) and an unknown wifi but as you don't say what they are that is impossible to answer.

Rather than asking, what I consider silly questions, why don't you just try?

  • i'll give a try but there wont be any damage to components and pi? Jan 21, 2015 at 14:33
  • 1
    The only possible harm is a corrupted SD card which you would need to rewrite. I consider that risk is so small I would ignore the possibilty.
    – joan
    Jan 21, 2015 at 14:44

Well, there's layers to that. If your power supply does supply 2A it should be ok, but most "cheap" ones won't go over even 1,2A or so. Also be careful with the USB cable you use to supply your Pi, cheap cables tend to cause the showing of the yellow lighting bolt. Also the voltage of the power supply matters, if it does not supply stable 5V sharp (or a bit more) all sorts of problems may arise.

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