Stage 2 of 10 · 7 lessons · ~4 weeks
Electronics you need
Learn enough circuit theory to wire parts safely: Ohm's law, resistors for LEDs, voltage dividers, logic levels, pull-ups, a shared ground and clean power.
Start: Ohm's law and powerLessons· one lesson for each topic, in this order
Do this
- Buy or borrow a multimeter, a breadboard, jumper wires, LEDs, resistors and buttons.
- Calculate an LED resistor for your board's voltage and check it with the meter.
- Wire a button with a pull-up and confirm the pin levels with the meter.
- Design a divider that scales a battery voltage into your input range.
- Write down your board's logic level and which of your modules are 5 V.
- Draw a simple schematic of your first circuit, by hand or in a free tool.
Start with
- BookFreeAll About Circuits Textbook
All About Circuits · Beginner
Free: read the DC volume chapters on Ohm's law, series and parallel circuits and dividers
Keep handy
Also worth your time
Why 3.3 V and 5 V parts need care, and how level shifting solves it
Before moving on: An LED with a calculated resistor and a button with a pull-up wired on a breadboard to your board, with your calculations written down and the resistor voltage measured to match within a reasonable margin.
The Raspberry Pi is a whole computer, so a wiring mistake costs more than a microcontroller. Its GPIO pins are 3.3 V only and not 5 V tolerant: check every module before connecting it, and use a proper power supply for the Pi itself.