Some of our labs involve building basic electronics to interface with the Raspberry Pi’s general purpose input/output pins.
The most common electronic devices that we use include: resistors, LEDs, pushbuttons, transistors and speakers. All of the devices are connected by plugging them into the breadboard. Circuit power is provided by the Raspberry Pi and sometimes another battery source.
CircuitLab is a easy to use online electronic circuit simulator. You can draw out the electronic schematic and make voltage and current measurement. The next step is to compare the measurements to your calculations. This application also allows you to tweak the electronic devices to match your actual values. For example: Say that your breadboard circuit’s 330 ohm resistor measurement is really 321 ohms. The CircuitLab will allow you to adjust the circuit schematic resistor value in order to provide better online measurements.