Appendix

What you may have missed by using just the lab kit

Your lab kit just scratches the surface of possible parts that can be used with the Teensy. There are also lots of tools that can be helpful for design and debugging that could not be included for price and size reasons.

The Mechatronics Design Lab at Northwestern University has 8 lab benches with variable power supplies, oscilloscopes, function generators, benchtop multimeters, and more. When it is safe to do so, please stop by to check it out.

Soldering

A good mechatronics bootcamp should include the opportunity to solder some components. When you have prototyped a circuit and are ready to move to a more permanent device, the breadboard can be replaced by a solder-able protoboard or a custom designed printed circuit board. These require the components to be soldered to be reliable.

Soldering is the act of welding electrical components with solder for the purposes of electrical conductivity (there is also a version of soldering to make a mechanical joint, like in a pipe, electrical soldering is much lower energy process). Soldering uses a 30W iron in the shape of a pencil (not a gun or torch, those have other uses). To solder, mate the two conductors, heat them to the melting temperature of solder using the iron, and apply solder. Soldering is all about heat transfer: if the conductors are not hot enough, the solder will not melt and wick into the joint. To aid in transferring heat from the iron to the conductors, solder is applied to the tip of the iron because the liquid solder bubble transfers heat more effectively than dry metal-to-metal contact. The solder bubble does not leave the iron tip, it is only there to help with heat transfer! Solder is not applied like glue in that way.

When you get a chance to try it out, try:

  • Solder two wires together
  • Solder the strands of a stranded wire into a solid wire
  • Solder a resistor into a solder-able protoboard
  • Remove a component from protoboard and suck out the solder
  • Solder header pins into a breakout board

3d printing and Laser cutting

Most projects will need some mechanical parts and an enclosure to house the electronics. There are lots of pre-made boxes available, but with a little time invested in learning computer aided design (CAD) you can model custom parts and use rapid prototyping tools to create them. It is tempting to 3d print everything, but laser cutting is usually faster and more effective, especially for parts that are mostly made of flat surfaces. Don’t let me catch you printing a box! Those should be made with the laser cutter.

PCB design

A printed circuit board can be manufactured and delivered in as little as a week for under $50. It makes a prototype much more reliable and professional looking. Check out these tutorials for using Eagle CAD to draw a PCB.

Links

  • Arduino code reference
  • Teensy website
  • General C help

Where to find parts

There are many websites that sell “breakout boards” for components that cannot be plugged into a breadboard. Before you buy, make sure the vendor has some sample code available.

  • Sparkfun Sells a nice array of Arduino and Raspberry Pi compatible parts

  • Adafruit Has very nice tutorials for all of their parts, strongly supports Circuit Python (using python to program the microcontroller instead of C)

  • Pololu Has nice sensor boards and high quality motors and motor drivers

  • Servo City Lots of different sizes of servos and servo attachments

  • Seeed Like Sparkfun and Adafruit, but pay attention to the shipping times

  • Hobbyking More powerful motors and moor drivers, lot of random parts, make sure to ship from a US warehouse

  • Digikey / Mouser / Newark Sources for low level components and an alternate supplier for the above vendors

  • Amazon Lots of stuff here but sometimes a low price is a knockoff part, also pay attention to weird shipping times

  • Aliexpress The best source for parts in higher quantities, but expect expensive or long shipping times