I’ve recently had this really strong urge to make. Simply make, no strings attached.The one thing I probably have the technical training to make, are electronic circuits. After 4 years of an electrical engineering degree and an year into my masters, I’ve picked up lots of interesting skills and bits and pieces of knowledge, but rarely have I ‘made’ anything.

I have fabricated organic transistors and microfluidic channels from scratch. Somehow fabrication does not equal make. Perhaps it was because the tools and protocols for their use were already set in stone. Perhaps the desire to ‘make’ comes with an implicit desire to show and tell. A desire to inscribe your signature on your creation for the whole world to see (or the minuscule fraction of it that is interested).

This desire to make was kickstarted by a course in Technology Entrepreneurship I took last term at UBC. Our team had to come up with a need, validate it, prototype it and come up with a slide deck as the final deliverable. My prototype of a pressure sensing insole using nothing but a couple of discrete sensors hidden inside a Dr. Scholl’s insole with fancy visualizations of the sensor data was well received. After the course wound up, we decided to see how far this idea would run, and I prototyped more. Owing to multiple reasons, the idea and the project folded but the seed to make was firmly planted in me.

What to make? There definitely were a few skeletons in my closet which I was not satisfied with the way I left them. The prototype of an electrical cautery system that we built for EiS could definitely be improved. The pressure sensing insole might have some mileage in it, if I coasted. There’s always ideas on the medical devices that I would be well placed to work on, given my background in electrical engineering and all the dabbling in bio related stuff.

Most ideas have a simple circuit on a custom made PCB at their heart. The techniques and skills required to design the board and selected the components vary with the application. The electrocautery project would require a deeper understanding of power electronics while a pressure sensing insole would require signal conditioning circuitry and efficient power management.

My current prototyping flow looks thus. I design circuit schematics and map out high level stuff on my trusted moleskine, while I use eagle to layout the boards. The boards are shipped off to OSHpark for fabrication, with a turnaround time of 3 weeks. The stencil if any, goes to OSHstencils and comes back in 2. The parts are usually sourced from aliexpress (~1 month) or sampled (<1 week). If there’s multiple lines on the BOM, it might make sense to order them from DigiKey, with a $8 shipping fee.

Once the board and parts come in, they’re assembled by hand either using the Hakko, the FX888D hot air rework station or solder paste and an electronic skillet with a thermocouple. I’m still a bit weak on the testing aspect though, I’m not sure the cheap multimeters on Amazon can measure high frequency or high voltage signals. A DSO would be great investment. Maybe in a bit 🙂