Sunday, June 29, 2014

File Under: Lessons Learned the Hard Way

Wowzers.  3 posts in one day, 4 in two... you know the shnizzit must be gettins realziz.

Everything was working just swell shortly after the last post - I soldered some wires for the speaker to the perfboard, and hand-twisted these around the wires attached to the dartboard's speaker. I screwed the perfboard to the mounts in the frame, connected the USB and ran my enhanced python test app (will upload to git shortly and link here, for all you monster fan boys out there).  It was working perfectly - the speaker spake, the hits were registering flawlessly, the LEDs were LEDing all over the place like the mad beasts that they are.

And then...

I untwisted the speaker wires and attempted to solder the ones from the perfboard to the speaker itself.  I think the existing speaker wires were attached with silver play-doh - or at least that's how it acted.  It sloshed around like some pseudo-plasmatic vomit and only succeeded in frustrating your humble narrator.  It was at this point that it was me against the speaker... mano y speako... except mano ceased to consider the hot soldering iron in his hand to be of primary importance.

Eventually, the wires were attached to the speaker with some fresh, solderesque solder and victory was declared once more.

And then...

The dartboard was again connected to the laptop and the tests were run again and tests began to fail.  Notably, the speaker didn't work. "C'mon!  Really!  Really? After all that?!" are words that approximate the feelings.  The triple ring, double ring and single wedges appeared to work from some quick tests - tests that were assumed to work since nothing really changed except for the speaker wires... but when I tried to hit a double bull to quit my testing...

(nothing)

Single bull - fine.
Double bull - nothing.
All numbers except 9 and 14 - fine.
9 and 14 - nothing.
Double bull, 9 and 14 all happen to share the same wire... row 3 in the matrix (in the code)... pin 1 of the first 595 shift register... pin "11" (first pin of the second row) of the 20-pin ribbon connector... nothing.

I resoldered pin 1 at the first 595. I resoldered pin 11 at the ribbon connector.  I checked continuity.  Everything appeared to be adequate.  But my blurry eyes noticed, as I flipped the plastic sheets over to try another retest, that there was a cookie monster bite out of one of the plastic layers.  Closer examination revealed that it was probably melted by a soldering iron and that it took a complete chunk out of only the outer most conductive trace on that side.  Following the broken trace back to the ribbon and 20-pin connector, it led to the 11th pin... following it the other way, it led to 9/14/double bull.

"C'mon!  Really!  Really? After all that?! REALLY?!?! AFTER ALL THAT?!?!" ... or something like that.

I tried to bridge the gap with electrical tape and a small piece of wire, but it would not budge a metric inch.  My thoughts once again started to frantically consider other hobbies.  Scrapbooking sounds, well, completely awful (to me --  I'm sure it's spiritually, intellectually and artistically fulfilling for tons of people, but my fraction of a ton simply does not contribute to that total).

Then I remembered that I have an electronic dartboard on deck, and yet another in the hole.  The first was within arms reach during this crisis, so I quickly had the back cover removed and the wires violently separated from the dartboard factory's obviously inferior brainboard.

My perfboard would not even come close to fitting in this new frame, but the sheets looked like a match - they actually look a little better-made.  The patterns on both sides are essentially the same, but the layout looks a little better, nicer, cleaner, safer... can't explain it very well at the moment, but I'll take a polaroid of it and post it so you can see what I mean.

The ribbon connector is also essentially the same, but instead of one 20-pin connector, there are 2 ten pin connectors...10 wires on one side and 7 on the other - same deal.  I desoldered these chumps, easily needle-nosed away the glue that tried to hold them down more permanently, and this factory board was tossed on the bones of the other one.

When my gumption levels are sufficient, I will desolder the old ribbon connector from my circuit and solder in the new guy.  I might use the new dartboard's speaker as well, if it accepts my solder more readily than the other bastard.

Yeah.  A lesson was learned today.  If the project frustrates you, put down the soldering iron and step away from the electronics.  Count to 10 in a numbering system other than base 10, preferably octal and then hexadecimal... and then nobody gets hurt -- not you, not your self esteem, not your project.  And, nobody gets forced into scrapbooking.

No comments:

Post a Comment