Electronics Crash Course for Fab Academy 2018
Below are some discussion points for our preparation class that introduces electronics design and production for Fab Academy 2018 and other opportunities.
Electronics are a great way to add interactivity to your project, letting it react to real-world input and effect the world around it, in a much more complex, robust, and reliable way than just using mechanics. For even more complex behavior, you can add a microcontroller chip to your project and program it.
The Electronics Design Process
How do you get from an idea to a working electronic circuit?
- Describe what your circuit should do, in everyday language.
- Turn your description into a block diagram, showing what kind of input signals (e.g., from buttons or sensors) are flowing where (e.g., into an Arduino board or ATmega microcontroller), and what kind of output signals this generates (e.g., an LED to turn on).
- Insert iterative prototyping here (see below)
- Turn your description into a schematic, a logically structured diagram that shows your electronic circuit using symbols for each component, with voltage and signal connections, using Printed Circuit Board (PCB) layout software like the free version of Autodesk Eagle.
- Turn your schematic into a board layout that shows where exactly each component will be placed on your board, again using software like Eagle.
- Create your board, in our case by milling away some of the copper on a single-sided fully copper-clad board, leaving only the traces we want.
- Solder your electronic components to the board.
- Test and debug your circuit.
Iterative Prototyping: DIA Cycle in Hardware
- From a circuit idea, start with a very basic circuit and build it on a breadboard.
- Test and debug it until it works, keep notes on what you learned.
- Then add the next components to get closer to your final circuit, and repeat.
- When you have your entire circuit working on a breadboard, continue with creating the schematic as above
A multimeter is absolutely essential for testing. If you have signals that change more quickly than your eye can see (around 4 times a second), also learn how to use our oscilloscope.
The best tutorial book for this is Charles Platt's Make: Electronics book. They're in our library and on oliver (do not pass our physical or ebooks on to others!).
- Circuits, power, Ground
- Voltage, current, and resistance
- Through-Hole vs. SMD components
Kits for Experimenting and Teaching Electronics
The breadboard is a quick way to set up and test a circuit, but it also can be problematic due to loose wires, the invisible connections inside the board, and the general small scale that makes it hard to explain things and spot mistakes (like inserting a wire off by one row).
We have a Lectron kit that's much more useful to explain and experiment with basic electronics (no microcontrollers at this point).
Simple Electronic Components
The best reference for this is Charles Platt's Encyclopedia of Electronic Components Volumes 1, 2, and 3 (in our library and on oliver).
- Resistors, potentiometers
- Inductors transformers
- Diodes and LEDs
- Integrated circuits (analog and digital)
- Microcontroller boards, like the Arduino
- Actuators (including electromagnets, relays, speakers, motors, servos)
Drawing the Schematic
- Autodesks' own tutorial for schematics with Eagle (Part 1: Basics, Part 2: Nets and Values, Part 3: ERC)
Drawing the Board Layout
- AutoDesk tutorial Part 1
Milling the Board
- Instructions are on the page for our PCB mill. It's a more professional mill than the one in the default Fab Lab inventory.
- We have a separate page with a soldering tutorial.
- Eagle Tutorial for completing the ATtiny microcontroller circuit board.