So as I talked about in my previous post, I headed up to Dayton Ohio last weekend to witness Hamvention 2011 first hand. Well, what I failed to enlighten the world on is I had been studying to get my license so I could be honest-to-legal HAM operator!
I was able to take the test for free (it's normally ~$30) at Hamvention and once I passed (you doubted me?) had my call letters that night, yep, that's some effecient government work there, isn't it? I picked up a little Wouxun (pronounced woah-sean) radio to get me on the air quickly. With any luck I'll be getting a package in the mail with my base rig, a FT-7900R so I can crank up the amps and actually talk to some folks simplex...
Update: I've updated the design of the board and the transistors used to ensure better compatability with the Orbit valves. I was getting reports from folks that some valves would open but not close with the shield. The updated design can be downloaded at the bottom of this post.
I've been working on a rather large project for some time now and while my new h20 shield is just one piece of the larger project, I thought it deserved it's own post and documentation. I can see this shield being quite useful for lots of folks wishing to control water using one of the fairly inexpensive Orbit 62035 garden hose valves.
First, allow me to give credit where credit is due, the hard work for the control circuit and voltage booster came from this incredibly smart gentlemen and the shield wouldn't be possible without his hard work figuring out how to control the valves! His design for controlling the valves works wonderfully!
This shield is a three valve controller with LED indicators for valve status. I used the long headers thinking I'd make the shield stack-able but the 50v cap scrapped that idea. If I make another version, I'll use a different cap/layout to ensure you can stack this shield, as it now, this will just be the top shield in my project. I also used only through-hole parts (I normally would have used nearly all SMT components) to make the shield easier for folks to solder and I had many of the components in through-hole package on hand.
The circuit is quite simple really, it's comprised of two main parts, the 24V voltage boost circuit which is required to open and close the Orbit water valves and three open/close control circuits. The shield uses 7 digital pins and 3 analog pins. I have one pin each for open and close for each of the three valves, they each drive a transistor which close the 24V through one of the two valve connections. One will open the valve and the other will close it. The final digital pin is used to control the LT1303, when held high, the circuit will shut down thus saving power as the 24V is only needed when opening and closing a valve. I've used the three analog pins to control the LED indicators for the three valves, I needed the other digital pins for other shields that are part of the bigger project I mentioned earlier.
I've included high-resolution pictures of the completed board along with the Eagle schematic and board files and a sample Arduino sketch for those interested! As you can see from the video below, the board works perfectly! If you find a use for this design, let me know, I'm always fascinated by how folks use controllers like this!
Hello fellow geeks, as many of you may already know, Hamvention 2011 is this weekend and I'm heading up to Dayton to check it out. This will be my first time and while I don't have my license just yet (exam is June 21st), I'm stoked to have the opportunity to attend the world's largest HAM convention! I'm also quite lucky to be attending with some great folks who are HAMexperts. Perhaps a Yeasu FT-60 is in my future this weekend? What do you guys reccomend for a first radio?
Today was another good day! I got an email from FotoMoto letting me know that one of the photographs I had taken of the family cat was chosen to be featured on their homepage! Very cool indeed, I've always loved photography and it's nice to get any level of recognition for it! If you haven't heard of FotoMoto, check it out, it's a great way for folks to sell photographs, I had signed up so that when I get some great shots of the new baby, our family can very easily order prints if they want. FotoMoto is a great company and I'm honored to be featured for the day!
So with the new baby coming, my wife and I decided we needed to get a new camera. I think it's almost a fad with parents-to-be and while I initially refused the idea of spending money on a new camera (we had a perfectly good point-and-shoot), I eventually caved and started looking. Unfortunately I had forgotten exactly how much I loved photography and quickly realized I wanted a NICE camera. I ended up purchasing the Nikon D7000 and added a few bells and whistles.
Back in the day, I had my own setup to develop B&W photos and digital cameras were just getting affordable enough that I looked into them. It didn't take me long to turn my nose up at them, however. The cameras at the time left a lot to be desired at the price range I could afford so I naively dismissed them and never looked back.
It really wasn't until a few weeks ago that I gave the new DSLR cameras another look and boy am I glad I did! It's amazing how much can change in the span of 10 years! I couldn't believe my eyes, they had finally convinced me that DSLR cameras are as good (if not fabulously better) than my old 35mm film equipment. But I digress...
Having a few days to learn the camera, I quickly realized how symbiotic photography and my electronics really could be! It didn't take me very long to whip up a new circuit to emulate the IR remote that Nikon sales and setup some nice time lapse photography with my Arduino telling my camera to snap a photo every 60 seconds! I was giddy with excitement and after 1/2 hour with my best friend Google, I realized this could go way further. The type of pictures that I could capture with my knowledge of electronics and photography seemed limitless. The articles I had read showed some serious setups which used an Arduino as an intelligent camera trigger for sub-second action shots!
Oh yes, I think I'm going to enjoy (taking pictures of the new baby) this new camera!
Last year I decided to jazz up our family Christmas cards with LED power, inspired by this article. While I was totally happy with the cards I sent out, I was wanting something a bit more this year so I've decided to take it one step further and create Christmas ornaments for our family that will be sent with this year's Christmas cards.
I had a few criteria that drove my design for the ornament not to mention I had a very short timeframe so simplicity was important:
1. Have the same shape as a typical Christmas ornament (it is an ornament after all).
2. Lots of LEDs, folks in my family love LED blinky things.
3. Battery powered and last as long as possible on battery.
4. Hackable. I wanted the board to be easily hacked by family and friends that were so inclined.
5. Maximize the visual appearance of the front of the board (no through-hole components), I was also going to put a Christmas message on the front in silkscreen.
After a few hours piecing together the schematic, I was pretty happy with the reChristmasOrnamentsults. Ironically when I went to start the board design I ran into a simple but problematic issue of how to evenly place the LEDs on the round board, being the true geek that I am, I wrote a C# app which you can see in the ZIP file attached to this post. It gave me the x and y coordinates for each LED given the radius, origin and degree. Being late at night when I finally got around to laying out the board, this was a true life saver!
Once I had the LEDs placed, I decided to go back and add some blue and white LEDs on the neck of the board to enhance the "blinky" factor. Skip ahead 4 more hours and I had finished the board layout. I always give myself a day or two after the board is done before I come back to it and QA the layout, saves me tons of time staring at a problem and not seeing it! My QA found several issues and once resolved I sent it off to the boys over at BatchPCB.com for fabrication.
Fabrication typically takes three weeks or more but I was nicely surprised when my boards shipped after only 7 days and being the OCD type I am, I had to assembly one of the boards as soon as they came in the mail. It took me about 3 hours to assemble the first board, I was being overly cautious and deliberate in each solder and relearning how to use my hot air rework station. The total time for the first board included soldering up my homemade ATMega TQFP programming board which I used to burn the Arduino Uno boot loader onto the ATMega chips I had leftover from a previous project. I'll post about it in more detail later, I have a few minor tweaks to make to the design before I think I'll be totally happy with it, but it served me well for this project.
With the boot loader loaded, the final test would be attempting to load a sketch on it using my FTDI cable. To my total elation, it loaded the sketch without issue and my blinky utopia began! I was absolutely filled with joy when those LEDs started blinking away, who knew something so trivial could be so satisfying. I learned a lot with this project and I gained some important confidence in my design and layout skills which should serve me well with my next project.
As for battery life, I've adjusted some of the animations so that I could eliminate having all the LEDs on for extended periods of time and found that I was able to leave the ornament on constantly and the batteries died (the board actually froze) after about 40 hours. I thought about putting in a sleep mode after 6 hours of use or something but I think I'll pass and allow the user to just remember to shut them off, heck those inclined could do it themselves!
Well, I'm giving out the ornaments on Thursday (Thanksgiving) so that friends and family can enjoy them on their trees this holiday season, I sure do hope they enjoy them as much as I enjoyed building and designing them! Check out a video of them in action below!