Image for post
Image for post

Inventor Tales — Square

Sam Wen, named inventor of the Square card reader, tells some tales about the innovation process behind the world’s most famous POS device

Craig Watson
Feb 11, 2017 · 4 min read
Image for post
Image for post
Sam Wen sharing his patent through Retro Patents on Twitter

Sam: I was working at a large defense contractor in Saint Louis and going to night classes, trying to get out of the defense industry. One of my professors offered to introduce me to a personal friend who was building an interesting startup. I listened in and found it to be a very cool idea with a very cool mission. I started working with Jim McKelvey the very next day.

Sam: The earliest readers were very simple devices; it was really just a simple LR circuit that directly send the raw, analog swipe signal into the microphone port. The problem is that microphones are often designed with band pass capabilities to filter noise. Unfortunately, depending on the speed of the swipe, we’d see every kind of filtering technique in the resulting signal read by our software. We had to work on this particular algorithm for quite some time before it would become ready to ship.

In addition, these were the days before iOS’s Accelerate framework, and some of the more advanced computational SDKs for Android, so any more advanced, frequency domain techniques for reading our signal was not possible. The entire algorithm in those days were done in the Time domain.

Sam: At the time, the tentative name was “Squirrel” (later changed when we realized that SquirrelPOS was already a company), and the Square reader was going to look like an Acorn. In fact, the original software written to support reading credit card data from the reader was called AcornKit.

Another funny story was that we made some initial prototypes out of aluminum. By then, we already had the algorithms, and were playing around with final industrial design. We couldn’t figure out why the aluminum prototypes performed so poorly, until we used an oscilloscope and realized the aluminum was conducting the electric potential in our fingers and acting like an EKG!

Sam: Honestly, the fact that people use it and that it serves a concrete purpose. I get an immense feeling of satisfaction and responsibility when people use the Squares to power their business.

Patently Designed

We are fans of innovation and the intersection of…

Craig Watson

Written by

dad, husband, founder — music lover & electric bike aficionado, co-founder @soundwave, now product lead @spotify

Patently Designed

We are fans of innovation and the intersection of technology, design and gaming ♥️

Craig Watson

Written by

dad, husband, founder — music lover & electric bike aficionado, co-founder @soundwave, now product lead @spotify

Patently Designed

We are fans of innovation and the intersection of technology, design and gaming ♥️

Welcome to a place where words matter. On Medium, smart voices and original ideas take center stage - with no ads in sight. Watch

Follow all the topics you care about, and we’ll deliver the best stories for you to your homepage and inbox. Explore

Get unlimited access to the best stories on Medium — and support writers while you’re at it. Just $5/month. Upgrade

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store