For all that have been following and helping, Galileo now finally has
six working circuit boards able to fire all 48 red, 48 green, and 48
blue LEDs under Arduino software command.
We're now in the home stretch, getting the three sonic distance
sensors working and playing with different display patterns to wrap
this up, and move on to the next project.
That is fantastic! Jim you have put a tremendous amount of work into
this amazing project. We need to take pictures and a video for the
blog and wiki once you feel it is ready!! I can't wait to see it in
What was the issue Jim? Soldering / etc. with the boards or
software/firmware or a combination? I'm very curious too!
Q - How do you get six working circuit boards?
A - Fab eight and debug the heck out of the last three!
The first five of the boards worked great from the start. The last
three didn't. After an initial period of denial, and disappointment,
uncertainty and reality set in. Surprisingly enough, the boards
didn't fix themselves. You doubt and suspect everything and start at
square one to eliminate possibilities. You try all the wrong things
in order and then the last thing you do is the solution that fixed the
problem. It is always the last thing you do.
A methodical process of elimination proved that the Arduino and board
inputs worked for the good boards but not the bad boards. Using a
multimeter to ohm out pins and components on a good board compared to
a bad board highlighted differences that pointed to the trouble
areas. I think there was too much solder paste under some surface
mount chips and there were some hard to see solder bridges. Things
started to get better on board 8 when chip 1 worked and chip 2
didn't. I found some bent/bridged communication pins to chip 2 and
two output pins also had a bridge. After those were fixed, board 8
worked OK fine. Board 6 and 7 still have known problems, but who
cares cause we have six working chips to run with.
You make me so proud! Go Jim!