Hello, I'm trying to make my first project by using and arduino and 2 sensors ( PIR and moisture) but I have to power supply the sensors from and external source , so I wanted to power supply both sensors and Arduino from the same power supply, while also controlling the sensors with my arduino. I tried to connect them parallel and I wonder if this is how I do it. Sorry if the question is stupid, but it's my first time on this. I try to power up sensors from arduino directly, so that's why i want to connect everything parallel since I don't want to fry the arduino.
The 3.3V pin is an output only. The Uno requires 5V.
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sorry, i missclicked. I was meant to use the 5V pin. Other than that, everything should be fine?
Yes. Generally everything should share a common ground and the power supply can also be shared.
If more than one power supply is used (often the case with motors) you need a common ground between the power supplies unless there is optical isolation (or a relay which can also be isolated). Transformers can also provide isolation but transformers only work with AC.
I won t use more than one power supply. I will use one for both arduino and sensors
Welcome, you are one of the best, you included a good schematic.
You could power everything from an external 5V power supply. While building and debugging it should run OK with the USB connection. Normally I do not recommend powering with the Arduino but in the debug stage it should work OK.
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First of all, i missclicked and I wanted to connect the wire to the 5V of the arduino.
Basically it's the connection of the battery's positive to the arduino's +5V (not 3V3 like in the schematic)
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Yes, I try as much as possible to not power up things from Arduino.
Usually powering devices is the proper method.
However my first questions are:
- What are the required voltages for SEN1 and PIR1?
- What voltage is P2?
Your annotation is not incorrect, however traditionally you would call "P2-" "Ground" or "GND". You should only define a negative voltage if there is a voltage negative to your circuit ground.
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5V for those sensors. P2+ is the +5V and P2- is GND.
OK then you are pretty close, move the P2 line from the Arduino 3.3 to the Arduino 5V pin and you are good to go.
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