Hey guys, so I'm very new to using Arduino (this is my first project), and I have a rudimentary knowledge of circuits. I'm trying to copy Devon Crawford's music visualizer, and I'm very stuck at the moment. Here's the link to the video where he creates his, although he doesn't show much of the hardware building process in the video: DIY LED Music Visualizer | Real-Time Animations (Arduino) - YouTube . Basically he is using a frequency to voltage converter, and inputting the voltage into the Arduino.
I'm just going to use his code for the project for now, and then learn to write in arduino and create my own code later on. In the description he links the circuit that he used: http://mathscinotes.com/2014/03/a-simple-frequency-to-voltage-converter/ .
I've attempted to build the circuit, but it's not working. I just went to an electronics store and got the diode and transistor from the schematic, and capacitors and resistors with the same properties as those in the schematic. However, I'm unsure what needs to be connected in the "Sensor interface output" part of the diagram. Right now I'm trying to connect a 3.5mm jack with stripped ends to it, but it isn't working. Any help would be so so appreciated, as I just don't know enough to complete the project.
Also, here are a couple pictures of my circuit at the moment.