Built a simple Function Generator with Frequency Counter over the last couple of nights. It’s pretty basic — 0-~500kHz, 0-12V, Sine or Triangular waves — but good enough for my test needs. The frequency counter is basically an Arduino repackaged to feed the attached LCD. The counter isn’t super accurate, but is within 1% of what my multimeter says.
The kit has a fairly high voltage requirement for DC (>= 15V), but this was solved by a quick trip to Active Surplus. $11 bought me a 15V power supply (which delivers around 19V open circuit) and the right kind of barrel jack.
(Talking of neater meters, I didn’t know mine could support the Bluetooth Adaptor reviewed here. Dad’s old Avo couldn’t do that!)
I’d been surviving on a series of sub-$50 multimeters for years. They’d give an approximation of a reading,then fail miserably in a variety of stupid ways. The last one, a rip-off of an Extech, decided to show me how its wires were connected to the probes. “Barely” is a fair description.
So I thought I’d buy a decent meter. One that had heft and gravitas, like the Avo 8 that my dad used to bring home from work. The Avo — seemingly constructed from bakelite, glass and lead — didn’t just take readings, it told you The Truth on its mirrored scale.
So I bought an Agilent. Reliable company, all the right features, beeps politely only when required; a very, very sensible meter. Then I found these in the package:
Dude, what?! Skins on a meter? Meters aren’t toys. Meters are sensible things used by sensible people. We don’t want our work distracted by thoughts of Space!, America!, Sports!, or Some Kind of Bug Thing Eww Squish It Squish It! If you were able to get “skins” for the Avo 8, they would be about Wisden, sheds, and the TSR2.
Despite the sticky nonsense, it’s a good meter. I also managed to catch a Handheld Digital Multimeter Cash Back Offer, so it’s cheaper than competing Flukes and Extechs.