How to Make Circuits in the Fab Lab

Making a circuit requires several mini-projects:

Design and Architecture

Decide what function your circuit board should have

A good approach is to write down in words how the circuit board should work.

• download a cad file from the hello-world circuits section on the http://fab.cba.mit.edu/about/fab/ or from hello world electronics
• Look for open hardware solutions on the internet.
• Or design custom circuit

Create the schematic and board layout in a CAD program

Use e.g. Eagle or Cad.py, ,or Gimp (drawing tool), Inkscape or Open Office or draw it with black pen and scan and trace. The gap should be the right size and shape.

Physical Fabrication

Machine the board

Physically milling or cutting out the board which connects components

• Making circuit boards on Modela
• Making circuit boards on Camm with e.g. copper foil.
• Making circuit boards on Epilog Laser

"Stuffing": Solder components on to the board

Solder the components to the board. If you want to where the components should be you could look at the file design, in .cad file or you can check out

• Soldering -> Gisli
• Good Vs. Bad Soldering
• Circuit descriptons. pdf
• Scotts new Hello World Circuits description

Microcontroller Programming

Make a programming cable

• Make a programming cable -> Pedro

Write the Program

Write the program (in e.g. assembler or C) , compile the program so that the microcontroller will understand it -> Jan

Programming the microcontroller

If you are using the Fab Labs, AVR microcontrollers

• Use ICP (In Circuit Programmer)
• AVRDUDE

-> Jan

Testing and Troubleshooting

Test the microcontroller

Plug the microcontroller in.

• Is the power on?

Troubleshooting

If your board is not working, follow the step to troubleshoot it:

• Check if the power is on:

Check	Problem	Possible solution
Battery voltage	Voltage too low	Replace the battery
Microcontroller voltage terminals	No voltage or too low (it should be around 3,3 V to 5 V for the hello boards)	Follow the track and check every component voltage (capacitor, voltage regulator) Check the solder on the microcontroller or where there is no voltage If the solder is ok, replace the component

• Check if your cable is done right:
  • Follow the Make a programming cable tutorial to build a cable;
  • If the cable is done right, make sure the wires are making connection on the cbale connectors, by using the multimeter;

External Links

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