For whatever reason, some pictures decide not to load. I see the errors in my log on the server, as HTTP Code 304. Something seems to be happening in the voodoo my shared host uses to make my domain seem to be on its own box … “virtual servers”. Because I’m lazy I’ve been using relative links to my pictures, rather than absolute links; this doesn’t seem to play well with the hosts voodoo, so, I’ll be using absolute links from now on and hope that resolves things.
If a pic isn’t loading for you, please leave a comment or shoot me an email (gordonthree at gmail dot com).
*edit* thanks to linear for pointing out that 304 isn’t an error, it just means the content hasn’t changed… so I’m not sure what the cause was for those of you who mentioned you couldn’t see a picture – hopefully whatever it was, it stays fixed!
I’ve created a new page under Technology and Projects. Digging through my samples box, I came across the MAX1668 from Dallas-Maxim.
The 1668 is a five channel temperature probe with a serial interface. My final goal for this project is to hook the 1668 up to a large VFD display for monitoring temperatures.
Check it out … there are a ton of pictures, so dialup beware!
Exploration of MAX1668
Well… I probably won’t be posting any more project write-ups until next weekend, but I’ve noticed this brand new site is getting a few visitors already!
If y’all have any questions, shoot me an email at gordonthree at gmail dot com … or drop by http://forums.linear1.org
Here’s a cheap incandescent garden / landscape light I retrofitted with 4 RGB leds. It works OK, but the retrofit module is difficult to assemble without a proper pc-board and there are problems with diffusing the light properly.
I’ll revisit this project sooner or later
This breadboard is the first time I had dealt with high / super flux leds… otherwise refered to piranha or ufo package leds.
These came from www.lsdiodes.com and have a viewing angle of 45 deg… it makes them super tremendously bright looking indicators, and probably would work great for tail lights and such.
The piranha led has the chip or die mounted on a large heatsink connected to the anode … the cathode is also a heavy duty looking assembly, but its only connection to the die is a hair thin gold wire. The piranha led is an illumination grade led; it is designed to have a very high light output and be installed in close proximity to other leds of its kind. The large heatsink carries heat away from the die, but you still need to do something with that heat. The PCB board should have as much copper on it as you can fit, and the traces feeding the anode should be as beefy as possible so they can conduct heat from the pins.
I built this to test some “color washing” ideas I had, but it didn’t turn out like a hoped. In my mad rush to get it done (or maybe it was the post 1am state of mind), I wired it up backward… I was shootin for common anode, that is each led shares a common voltage supply and is controlled via their ground connection… but what I built is common cathode. Each led shares a common ground connection and is controlled by the supply.
Why is that bad? Well… If you’re going to use digital logic to control things, the easiest way is with a MOSFET transistor … the cheap and common N-Channel mosfets deal with low-side or ground connection … so with all the leds sharing the same ground, I cannot controll them independently.
WELL … I just tried changing to another theme I found on the wordpress site … whats that, you say, it doesn’t look any different. well, thats because I changed it back.
It seems the default theme formats my pictures for me, but the add on theme does not, so they distort the browser and layout all to heck.
Once I figure out how the default theme does the voodoo that it does, maybe another theme is in the future.
These little jems are serial controlled (i2c) PWM generators, designed by Philips Semiconductor for the purpose of controlling leds. I received samples of both the 9531 and 9533, which contain two separate pwm generators, and either four or eight outputs.
Above is a 9531 mounted to a prototyping adapter so it would go into a breadboard. Original tests with the chips were very interesting. The onboard pwm generator is capable of a wide range of frequencies and a full 8-bit gamut of duty cycles (256 steps). I ended up not liking these chips for a couple of reasons…
The biggest drawback is the chips only contain 2 pwm generators … while this would be great for a dichromatic white lite (yellow + blue), it’s no good for trichromatic (red + blue + green) … so the development would require two chips, and additional logic in the program to figure out which chip controls which color. The programming isn’t that big of deal… but I’m lazy. The second drawback is I couldn’t find anywhere to buy these. I don’t have any venture capital, so I can’t buy them in lots of 1000 from a regional distributor, and the supply houses I normally buy from didn’t have them in stock at the time I was working with them… so they’re on the back burner for now.
This is my protopod. I think I built four or five of these, some came out better than others … point to point soldering of jumper wires isn’t the best approach, especially when they’re all overlapping and what-not
each of those leds is rated at 200mW, but I’m only driving them around 100mW because they need a fairly heavy pcb with good thick traces to sink the heat.
you can see that I’m not the worlds cleanest prototype builder … but heck, I don’t care as long as it works
here is protopod fully illuminated
the peltier module sandwiched between two 1/4″ thick plates of pure copper. The hot-side plate is liquid cooled by a pump and radiator setup
the ice is condensation from the air, collected over the course about about an hour and a half. The pelt was being supplied from the 5v rail of the PSU .. the computer in the background is the guinea pig, but I’m waiting on some more parts to arrive first