Share an IR Reciever between 2 devices?

Projects General Guidance
1

I have a Raspberry Pi and an Arduino Micro. Since the Pi has no real power off, or at least can't power back on after a shutdown without cutting and reapplying power, I was going to employ an Arduino to handle this... Both the raspberry pi and the arduino will need IR Recievers for my plan.

Here's my question... Assuming that the IR signal used by the arduino is not used in any way by the raspberry pi, could I connect all three pins of the IR receiver to the Pi, and then also connect just the signal pin of the IR receiver to the appropriate digital pin on the arduino? I'm assuming I wouldn't need to connect 5v and ground to the arduino since it is getting those on the Pi?

Or would I just NEED to use two separate IR Receivers?

2

You would need to have the grounds connected, else the signal voltage at the Arduino will have no meaning, a bit like one hand clapping.

3

Ahh so the ground acts as electrical ground AND a reference point for the signal?

So I would only need the 5v pin of the IR Receiver connected to one of them, but ground and signal would need to be connected to both of them.

4

If it doesn't work like that you could build a circuit using the ir to drive 2 transistors then drive the pins on each with those. Maybe have to invert the logic with other transistors as I have not studied the ir library's. But it works great for driving two different things off of one.

5

Dalton63841:
Ahh so the ground acts as electrical ground AND a reference point for the signal?

So I would only need the 5v pin of the IR Receiver connected to one of them, but ground and signal would need to be connected to both of them.

Think of how you would measure the signal with a meter. You can't just jab the red lead onto the signal output: you have to jab the black one in on the 0 too 8)

But heed what drksam said too: the signal's voltage will be made available to both devices but I'm not 100% sure if there would be any significant current required from the sensor which I guess could fall short on that.... YMMV.

6

I think the RPi works on 3.3v rather than the Arduino's 5v. There would be a problem if the IR device lets 5v get to the RPi.

...R

7

Robin2:
I think the RPi works on 3.3v rather than the Arduino's 5v. There would be a problem if the IR device lets 5v get to the RPi.

...R

Except he said the IR is getting its 5V from the RPi in the first place.....

8

JimboZA:
Except he said the IR is getting its 5V from the RPi in the first place.....

Where ?

...R

9

Robin2:

JimboZA:
Except he said the IR is getting its 5V from the RPi in the first place.....

Where ?

In the original post:

I'm assuming I wouldn't need to connect 5v and ground to the arduino since it is getting those on the Pi?

10

JimboZA:

I'm assuming I wouldn't need to connect 5v and ground to the arduino since it is getting those on the Pi?

I did see that but I did (and do not) not have enough confidence in it to assume that the connection on the RPi would be at 5v. I just take it to mean that it would be powered by the RPi.

...R

11

After a little looking at the pi (I don't have one so im not 100%) but I see that it does have a 5v pin but the logic I/O pins are 3.3v. So a good reason to sperate the devices with the transistors. Then the ir can be whatever voltage u want and the transistors switch there respective voltages 3.3 for the pi and 5v for the arduino.