Building a circuit diagram (arduino project)

Thread Starter


Joined Sep 7, 2020
Hello. I am currently working on a project, where I have to build a people counter using IR sensor. I am working on the IR sensor and have made a circuit for it. I am working backwards, due to some problems, meaning I don't have a circuit diagram for the whole sensor. Right now I have made the circuit on a breadboard as a test to check if the sensor will work. I have to create a sensor with the same components I then can solder together myself. I really need help building a circuit diagram based on these components and what I have made on the breadboard. I have attached some pictures that might be relevant.

Listed below are the components that I have used:

- IR receiver - LPT 80 A
- Infrared emitter - SFH 4841 E7800
- Voltage comparator (OPAMP) - LM111
- Digitalt trimmer potentiometer DS1804 NV
- Power MOSFET - IRL530N
- Effect Resistor på 1,5 Ohm, 1 watt
- Capacitor 470nF og 10mF

Resistors used:
3 x 10kohm
2k2 ohm
332 ohm

I really hope, that someone can help, or at least do a part of the circuit diagram. I am kinda stucked.

Thank you!
Best regards meetoo25



Joined Mar 19, 2019
Start the circuit schematic with the power supply on the left side of the paper, plus voltage to the top of the page and ground to the bottom of the page, and start sketching in the components as you come off of the power supply to ground. First go may not be pretty but it is a skill you will have to learn by doing. And learn standard component symbology.


Joined Mar 30, 2015
I really need help building a circuit diagram based on these components and what I have made on the breadboard
Well drawn (e.g. neat and easy to read/understand) schematics are more art than science.

Start with a block diagram. That will help you organize component placement in the schematic.

  1. The preferred flow in a schematic is left to right and top to bottom.
  2. Don't use unnecessarily long wires or wire bends.
  3. Minimize wire crossings.
  4. Don't draw wires over symbols or labels.
  5. Positive power always points up and ground always points down.
  6. Label pins on any module or integrated circuit.
  7. Assign component designators (e.g. R1, R2, D1, C1, ...)
  8. Don't use colors.
  9. Don't use cartoons to describe circuits.
Here's an example of a cartoon:
From this thread.

This is my redraw that places the blocks more logically to remove unnecessarily long wires and minimize wire crossings: