Front of Makers Quilt Board 2
After a lot of unsoldering and resoldering I have the board properly rebuilt. I went from 30 AWG wire to Wire Wrap wire which is much better. When I wired the matrix to the drivers I alternated blue and white wires to better track where I was. Once that was done it was time to verify all the wiring. Out of 48 LED’s I had three bad ones. In the interest of time I went to Radio Shack and paid $1.49 for a pack of 2 3mm LED’s. I still have to slap together some Picaxe code which is 75% done. I should be finished by Sunday.
Old wiring with 30 AWG Wire
New Wiring using WIre Wrap wire
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Added a dog collar for a strap and snapped it all together and voila I’ve got a pretty nifty case. See …
Case with the Jacks and the Strap installed
Now on to Project #3. This is going to be a clean up of my Makers Quilt Board #2. I built the board awhile ago but it was a total mess and needed more LED’s to properly display my son’s birthday. I’ve already added more LED’s and another driver. now I have to clean up the wiring. This project is mostly soldering but it’s gotta get done.
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After finding out the power supply was not regulating properly. The voltage dropped to 4.8 Volts if I had more than 12 LED’s lit. So I re-wrote the code to prevent that from happening. With no LED’s lit the board puts out ~8.05mA With one LED lit the board puts out ~29.2mA. I’m probably going to change the current limiting resistor on the on 6276 to 1.5K. That should drop the Current Draw from the LED’s to around 15mA.
I hooked both boards up to test and one of the LED’s on the first board has blown. With both boards running the power supply had trouble regulating. Proof positive of two things. I have to raise the current limiting resistor on the drivers and I need to get a better power supply before board three gets wired in.
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I just found out I can run my Picaxe programmer from a VM. No need to leave my Linux box to program the little buggers. This should all be a moot point when I switch to AVR’s
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I swapped out the Picaxe 08M for an 18X. I’ll run some tests this weekend and hopefully have this board done and connected before the next Make NYC meeting.
Halloween prep has also been going slower than I expected. My motivation is just not happening.
I need to set some hard deadlines on some of these projects and honor them. It’s hard when you don’t have to produce results for anyone but yourself.
Second board finished by Friday
Tombstones ready for painting by Saturday
3 LED Spots ready for enclosures by Sunday
There I’ve said it and if anyone is watching you can hold me accountable.
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Looks like board two will get a different Picaxe. I’ve been running into some odd problems that look like they are related to the code being to long for the device. The Dev tools are not very good about letting me know this. Luckily we’re talking about a few wires so this can be pretty quick.
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Finally wired the second board up. I’ve been pretty busy lately so I’m trying to prioritize working on the board. All that’s left is the code.
I was running some code tests and had a timing problem. The bit banging code I used was sending the clock pulse before the data was valid. A 1ms delay fixed that up nicely.
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OK quick update on the second board …
32 3mm Red LED’s are soldered in and ready to go.
IC Sockets go in tonight and an interim picture will go up.
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Took my daughter camping and the family is going away this weekend. Pretty busy on a few other projects … home repairs and a scout trip to the Bahama’s.
Ordered the parts for board number 2. As I said it will be an LED matrix with my sons DOB. Why is it so hard to find Maxim parts? I ended up using an Allegro A6276 instead of the Maxim part I wanted to use. I picked it up from Newark Electronics.
I will be documenting this build with photo’s.
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