‘Unlocking’ RS232 output from your multimeter

There is a band of products within the handheld multimeter market which, regardless of the manufacturer, are all based around an IC family from Taiwanese manufacturer CyrusTek. You can see this in Dave Jones’ multimeter teardowns – nearly all the units he opens up have a CyrusTek IC running the show. So in terms of feature sets they are all on a fairly level playing field; the price spread mostly comes from build & component quality and the user interface design.

If you read the datasheet for those ICs – the ES519xx series – you’ll make the interesting observation that they all do RS232 compliant output. So a vast number of multimeters – quite possibly yours - are capable of serial communication, but most manufacturers don’t break it out to the front panel for you.

Garage door opener

Here’s a quick description of a project that’s a few years old now. My parents have an automatic garage door, and it has some lights that come on when the door is operated. One of the lightbulbs had blown while I was visiting, so I was up a ladder sorting it out.

As evidence that I’ll never be a professional electrician, while doing this I managed to accidently short a section of the control board to earth with a screwdriver.

Spoofing magnetic swipe cards

About a year ago I threw a magnetic swipe card reader into a larger Digikey order. I didn’t have any specific plans for it at the time; mostly I was just curious to learn about swipe cards and what kind of hidden information I was carrying around in my wallet.