Stuffomatic – manual “pick and place”

I finally got a chance to test out this little invention I call the “Stuffomatic”. It is used for stuffing circuit boards with components by lighting up the correct part bin. It is activated by a footswich, and uses a Teensy 2.0, buzzer, OLED 2×16 character display and a MAX7219.

While manually stuffing and hand-soldering Therevox circuit boards, I wanted something that would speed up the process and cut down on errors. On first test, the stuffomatic seems to speed up the “stuffing” process by close to 30%. Grabbing a component directly out of the lit bin is also a lot less prone to errors, compared to the normal way (reading the reference off the board, cross referencing it with the Bill of Materials to get the part value, find the right value part bin, grab the part).

The stuffomatic advances to the next part when a footswitch is pressed. I used a buzzer to make a small “click” noise when the footswitch is pressed for some audio feedback. There is also an “up” and “down” switch on the stuffomatic to quickly go through the list of parts.

The only problem with this project was that the Teensy couldn’t store the entire BOM (bill of materials) in memory. Instead, larger amounts of data need to be stored in PROGMEM which requires very messy code to declare the variables. To get around this, I wrote a PHP script that reads a CSV file and outputs the PROGMEM variable declarations as a 2 dimensional array. This also makes it easier to recompile the stuffomatic code for different projects.

On the front of the stuffomatic is a “note” LED to draw attention to the display if there is a special note or instruction being displayed. The stuffomatic can show messages like “flip board over” or “solder”, or a specific component might have a note with it.

So far I’m happy with the stuffomatic, it did take a lot longer to finish than I expected, but building it was more fun than stuffing circuit boards.

New CD in the mail

Me, Brian and Tim finished recording last month and I just got the CD’s in the mail today. I’m happy with how they look, and we had a lot of fun recording these tunes.

If you’d like a physical CD, they are $10 through the bandcamp page.


Recording therevox

Me, Brian and Tim finished recording our 6 song album last week. I couldn’t resist adding a little Therevox ET-4 onto the last track. This is going through my Yamaha E-1005 Analog Delay (for sale if anyone’s interested) with the ET-4 panned to one side and all the delays panned to the opposite side.

Garage sale speakers, counter top and dust


Nice luck = finding a pair of studio monitors for $10 across the street at a garage sale several days before starting to mix an album!


This is a counter top I made out of some maple. It is finished naturally, but I probably should have stained it a bit “colder” to remove the pink-ishness that maple seems to have under cfl.


From the winter, very dusty! I gotta say that a full face mask for wood working is pretty awesome. It makes you feel like an astronaut and you can never forget your safety glasses – Norm would be proud.

Super Fan prototype #1

Some pictures of my first prototype window fan. Trying to not use the AC again this summer, but my crappy garage sale window fan ain’t cutting it. I’m using a 12″ diameter 12V 80W automotive radiator fan and a high efficiency 100W switch-mode power supply. The fan is rated to be 1600 CFM, I can’t measure to verify but it definitely moves a lot of air.


I was hoping to make something that moved a lot of air but didn’t use a lot of electricity. These radiator fans were the most efficient I could find, and the total draw is 88W which is less than my off-the-shelf fan and a lot windier (breezier?).


One toggle switch for power, another for fan direction. The off-the-shelf fan I was using previously had to be removed from the window and put in backwards to change direction, so this is a very satisfying $3 direction switch.


I also added a metal frame to hold a 2″ air filter and foam pre-filter. The hope was to filter the air before it gets sucked into the room through a MERV 13 filter since we live on a very busy street. The metal frame was laser cut and bent on a small brake.


Unfortunately the filters really affect how much air the fan moves, almost stopping it entirely. That’s prototyping though, otherwise the fan is working great. The air isn’t being filtered before it comes in though, but I scored a second-hand austin air healthmate for cheaper than I could build something similar.

The fan motor surface temperature got up to 60C after being on for about 30 minutes, not sure if that’s a problem yet though. Woo, prototyping!