Archive for November, 2008

Chronulator Control

Saturday, November 29th, 2008

Oh, one more little tidbit.

I wanted to see something meaningful on my Chronulator, besides the time. So I cranked out a bit of Python code to read the SNMP statistics from my Internet gateway. Now, the “hours” meter shows how much stuff I’m downloading, and the “minutes” meter shows how much stuff I’m uploading! It’s pretty cool to load a Web page and see the meters dance around. For extra credit, I set the LED backlights to light up whenever the upload or download rate is above 5%.

If I have some spare time tomorrow, in between all the documentation work, I’ll try to make and post a video of the bandwidth indicator. It’s fun to watch!

Over the next week, I’m going to see what other gadgets I can code up. I’ll put all this stuff on the Web site — for you to learn from and modify for your own evil purposes!

Ordering, Documentation, Web Site, Pre-ordering!

Saturday, November 29th, 2008

Yesterday, I ordered the components for 100+ kits — chips, meters, resistors, capacitors, and all that good stuff. The circuit boards were ordered back on Wednesday. I also ordered shipping boxes and padding. All the parts should arrive by the end of the week (December 5). Once I get the documentation and Web site updated a bit, I think we’ll open for kit pre-ordering around the middle of this week (December 3, perhaps?).

Today, I worked on the documentation. All the photos and diagrams need to be updated because the design has changed dramatically to accommodate the Atmel chip. I’ve replaced most of the diagrams already. Tomorrow, if the weather is nice or I can find some decent light, I’ll re-photograph the assembly process and drop those photos into the documentation too. There will also be a couple of extra steps, as the Atmel ATmega168 microcontroller requires a few extra components that the TI microcontroller didn’t.

I also worked today on improving the timekeeping accuracy of the clock. The capacitors that hook up to the quartz watch crystal have a small effect on the speed of the clock. My tests show the clock running a bit fast (about one second a day), although it’s well within the tolerance I should expect from the crystal, and about as accurate as your average wristwatch or wall clock. I was just thinking I could make it a bit better. In any case, there’s the strong possibility I’ll hack the Chronulator to connect to an atomic clock receiver or GPS.

I enhanced the Chronulator serial command set to permit control not only of meter needles, but also the brightness of the optional LED backlight behind each meter. That should make hooking your Chronulator to a computer just a bit more fun…

Chronulator on Flickr!

Wednesday, November 26th, 2008

I don’t think I ever mentioned — there’s LOTS of pictures of Chronulator projects on Flickr! The craftsmanship just amazes me…

Chronulator 2.0 Number 1

Wednesday, November 26th, 2008

So here it is, Chronulator 2.0 number 1, photographed on the ShareBrained trademark kitchen tablecloth. It went together well, with just a couple of tweaks.

First, I forgot/neglected to connect power between the ISP port and the AVR chip. That’s no big deal for the 95% of people who don’t need to load their own bootloader. But it should work, so I’ll make it work by revising the circuit board.

Second, the circuit board holes on the quartz crystal were too close together. Therefore, there was no room for the solder mask treatment between the solder pads. And that made it hard NOT to create a solder bridge between the two pads, which would make the Chronulator not work. So I’m going to change the board to put some more space between the pads — enough to get a thread of solder mask in there…

I made these changes and will submit the *new* final design for manufacture tomorrow. I’m going to grit my teeth and pay for one-week turnaround. It adds about $1 to the cost of the kit, but will allow me to ship kits a week earlier (the plan now is to ship the first round of orders on December 8th). People love to give (and get!) Chronulators as gifts, so the sooner I can get them on sale, the better!

OK, with the details out of the way, I want to explain a couple of new things about the design:

First, the Chronulator 2.0 now uses the Atmel ATmega168, the same chip in the popular Arduino device. I’ve also included a port for an add-on USB-to-serial adapter (the SparkFun FTDI basic breakout board), through which you can program, control, and hack your Chronulator using the Arduino software. You can also power the Chronulator from the USB port, if you want to use your Chronulator with your computer.

Notice the lights on the meters? I’ve put places on the board for you to add high-power LEDs you can use to illuminate your meters. My experiments thus far making transparent meter labels have been not-so-successful, but I’m hoping my talented and creative customers can come up with some clever solution.

There are also spare pins you can connect to on the board. You can use these extra pins to control additional LEDs, another meter (for a “seconds” hand), or hook up to external devices like an atomic clock receiver module, GPS, various analog signals… Who knows? I’ll be posting the results of some of my hacking experiments. I hope you’ll do the same as you experiment with YOUR Chronulator!

Prototype boards on the way!

Monday, November 24th, 2008

I just received notice from Advanced Circuits that the Chronulator 2.0 prototype boards have shipped and will arrive tomorrow afternoon! The Digi-Key parts for the final prototype arrived today. So tomorrow evening, I’ll solder up a board or two and try ‘em out. If they work fine, I’ll put in the big orders with Digi-Key and Advanced Circuits. It’ll be about two weeks before we can actually ship kits. In the meantime, I’ll open up the store for advance sales.

Chronulator 2.0 Design Complete (I think…)

Tuesday, November 11th, 2008

I just finished up the design of the Chronulator 2.0 board. It’ll have a few nice features and more expansion possibilities than Chronulator 1.0. I’m hoping people will have fun hacking and enhancing their Chronulators, since one of my primary motivations is to help people learn a bit about electronics and programming.

I still need to test a couple of changes I’ve made in the design — they’re changes I made in the circuit board, but not in my prototype. So I need to test these changes on the prototype and make sure I’m not getting myself into trouble…

I’ll post some pictures of the final prototype in the next couple of days, and you can see how messy it is!