Jurek and the Amazing Techno, Colored DreamWall

Jurek and the Amazing Techno, Colored DreamWall

The title is mostly a placeholder, as I haven't really figured out a name for it yet. This project is a wall hanging that consists of semi-large triangular pixels using discrete RGB LED's and PWM to control intensity levels of each LED, resulting in a 4096-color display.

Thursday, June 30, 2005

Assemblyline production (part deux)

LED Driver Boards

I must be getting better and more efficient at this soldering business.

It took me 3 hours to do boards #2 & #3 on Monday night. But by the end of board #3, my brain was kinda fried and I ended up soldering 2 of the headers on the wrong side of the chip before I realized it. It wasn't a big deal because they're just the headers for the LEDs, but it was still a screw-up.
Last night I decided to eschew the cross-pin resistance checking. I figured that it was just wasting time and probably making the solder connections worse in the end. Any sort of resistance was probably being caused by the flux and not because the solder between pins was "getting too close" to each other. I also decided to move towards a more-assemblyline approach and did 5 boards at once.

In total, it took me a shade over 3 hours to do all 5 boards.
On the top side, I spent 50 minutes doing all 10 driver chips, which included everything from fluxing the pads to doing connectivity testing and pin short testing. This comes out to being 12.5 seconds per pin. Not too shabby.
The bottom side faired even better for speed. It took me only 30 minutes to do all 10 driver chips. This comes out to be 7.5 seconds per pin, or 8 pins per minute. Basically, it was taking me about 1.5 minutes to place, align, and solder the chip, and another 1.5 minutes to test it.
Of the 480 driver chip pins that I soldered last night, there was only 1 pin that wasn't soldered correctly the first time and none of the pins were shorted. Yippie me!

I can't do any more boards at the moment because I've run out of driver chips. My initial order was only for 40 and I've used a few here-and-there for testing previously. So I need to order a few more of those before I can continue.

Wall Construction

I only spent a little bit of time on Tuesday cutting wood, but I basically doubled the amount that I had before and started on 6 more internal pieces. I realized that I need a lot more 1/2"x3" pieces and that the way I was cutting the small 5.5" pieces wasn't the way that the majority of them would need to be. Luckily, I only cut 4 of them this way (I need either 8 or 16 of them)... Wood is cheap anyway, so it wouldn't have been much of an issue either way.


I'll have to really dig into designing the microcontroller board now. I'm going to run out of stuff to do with the two current projects relatively soon, so I need to work on the other areas as well. I also need to decide on LED's. I still haven't purchased any large amounts of them or the resistors to go with them. I need to get a power cord for my power supply too, so I can test the LED's with the correct voltage.

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