Hello Arduino

Success has been had … finally!

A couple of days ago, a tiny little package arrived from Sparkfun Electronics with my first Arduino kit. Valerie’s response upon finding said package in the mail box, “well, so much for seeing my husband for the rest of the week”. In all fairness, I waited till the second day (night, really) to get sucked in. I’ll be back tomorrow…

Last night, I just plugged it into the USB port and loaded a pre-canned example that made the LED blink. Did some experimenting with modulating in and out with a few for loops just to refresh my C code.

Tonight was all about getting the LCD wired in. Soldered a header onto it to mash into the bread board to keep the wiring flexible.

Opened up the LiquidCrystal tutorial and wired it all up and measured the resistance between power and ground to make sure I didn’t have any shorts. Finally plugged it in to the USB spigot and dumped the “hello, world” example program, and … nothing.

Hmmph. Take some measurements — voltages are good. Contrast voltage bias is about half-way, that ought to be close. Let’s try a little higher: nope. Lower? Nope.

OK, rip it all out and move to a different section of the breadboard. Still nothing. The LCD doesn’t so much as blink. Must be dead.

In fit of desperation, I grab pair of random resistors and jumper them across my voltage divider that’s biasing the contrast, first moving contrast closer to VDD, then moving it much closer to VSS and — presto — it was running all along.

It’s alive!

NIKON D70, ISO 500, ƒ/1.8, 1/30sec, 50mm focal L.

For the record, this particular 5-volt LCD contrast likes to biased at about 1.3 volts. 2.5 volts get’s you nothing.

My first real “project” is to build a rechargeable battery characterization tool. More on that later…

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