Hello
I am a complete beginner and so don't have much idea at how circuits and circuit simulation works
I am currently working on building a photogate and working with the video :

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I am trying to simulate the circuit that is shown at 2:03 using a simulator like docircuits. I cannot seem to figure out how to complete the circuit because in actuality, these sections will be joint to the raspberry pi and so how do i simulate the raspberry in the simulator or how do i connect the dc voltage providors (+5.0V, +3.3V etc) with each other to connect the circuit. Also, how do i measure the input value (with a voltometre? but again, what does the voltometre connect to). My attempt is attached as a png.
Thanks in advance

 

You don't need to simulate a raspberry pi to test this circuit.
R3 appears to be shorted out.
You can use a single supply for the entire circuit.
How do you intend to simulate the virtual light from the virtual LED falling on the virtual photo-transistor (although it just looks like you've used a normal transistor with no base connection)?

Better just to build the circuit, there are only 4 components.

 

Thanks for the reply. I was unsure of where the base connection was supposed to connect to so i left it blank for the time being. How do I connect all of them with a single source. Virtual light and phototransistor, i am unsure.
Yes, i will probably just build it, i am just waiting for a few resistors.

 

Connect the supply to the top of R1 and R3, you don't need two power-supplies. You can't simulate this because a simulated LED does not emit light and a simulated photo-transistor does not respond to light.

 

Oh, ok. I will probably just make it then as simulating it is probably more work and more inaccurate. It is a very simple circuit anyways.
Thanks for the help