Chronodot Library for Arduino

Posted 2011.04.09 22.44 in Computers/Internet/Technology by Stephanie

When I was working on my Thermostat project, I came across the Chronodot RTC (real time clock) and decided it would be the perfect choice. Not just because it’s incredibly accurate, but because it provided both time and temperature readings in a single package. I could have used another RTC such as the DS1307 which is less expensive, but then I would have had to use something else for reading the temperature.

The only thing about using the Chronodot to get temperature readings was that there wasn’t an Arduino library that could get me that information. The Chronodot communicates using the i2c protocol, and as I hadn’t used it before I was hoping to find some examples and a usable library. Fortunately it’s compatible with the DS1307, but of course that library has no reference to temperature as the ‘1307 doesn’t read the temp.

So using the ‘1307 library as a starting point, I expanded it by adding two new readings to it: temperature, in both farenheit and celcius.

The library includes an example sketch. If you’re familiar with using the DS1307 with an Arduino then the Chronodot library will be an easy drop-in replacement. The time features are unchanged, I’ve just added the two temperature readings so they’re available within your sketch.

Click here to download the library: Chronodot_Library.zip

Reminder about Safety

Posted 2011.04.09 18.16 in Hobbies, Pointless Blather by Stephanie

I’ve been pretty good about doing the safety goggles thing when it comes to playing with lasers. But for general electronics work, it’s just never occured to me that they’re necessary. I mean, snipping component leads, working with solder, even some mechanical stuff like drilling or cutting enclosures… it just didn’t seem that dangerous.

Then, cutting a little hole in a plastic enclosure for a switch, and ZOCK!

Tiny metal fragment, right in the eye!

It came off the edge of the blade – a tiny little fragment of the cutting edge of an x-acto knife, straight into the right eye! Ok, now I suddenly recognize why safety glasses are a good idea even with simple electronics.

I was able to spot it with a mirror and a bright light, but couldn’t get it out – it was too tiny and looked like it was sort of stuck in the white part. Then I blinked and it ‘vanished’. Now I don’t know where it is… I suspect it’s lost in the conjuctiva under my eye.

Now my eye is vaguely itchy but I’m not sure if that’s from the metal chip or from me poking around in there trying to find the metal chip.

So anyhow, let this be a lesson — eyeball safety, is always a good idea!