Member Since: September 26, 2009

Country: United States



I was an Electrical Engineering student at Purdue University. By day I'm a software engineer at EasyDial, Inc., a medical startup developing a portable dialysis machine. By night I teach at a local MakerSpace, and am also a competitive ballroom dancer.


Software Engineer


EasyDial, Inc.; Dwyer Instruments, Inc.; American Scientific Affiliation

Spoken Languages


Programming Languages

ANSI C, Assembly, C#


Purdue University

  • When you find out, let us all know :)

  • Cool device! So, in theory, could you connect two of these in series and set one to "left," the other to "right," and get stereo from a Pi-Top?

  • What do you guys recommend we set our soldering iron's temperature to when using this? I've been setting mine to 600°F (316°C), but the flux splatters a lot, which is unpleasant. Any useful tips?

  • Oops, I think the BQ27441 is a ROM-based part, so it may not support the firmware updates that TI's other Flash-based fuel gauges do.

    Oh well; perhaps my program will benefit others experimenting with TI's other parts :)

  • Hello! The BQ27441 Fuel Gauge is a flash-based part, which means it has its own firmware that can be updated if you want to better suit your particular battery or application. My former employer has allowed me to open-source a project I made that allows you to use an Arduino or Energia compatible processor to program flash-based gauges. Here it is.

    If you want to do this, or want more information about this chip and why you'd want to program it, see the Technical Reference Manual, which should probably be added to the product description.

    One word of warning: flash-based gauges can be permanently bricked if you program them with bad firmware. TI recommends that if you try to program a flash-based gauge, you should have several on hand in case one is rendered inoperable. I probably destroyed at least 10 gauges when I was debugging the sketch.

  • You don't need a teaching certificate to teach! I'm an engineer in Northwest Indiana (about an hour from Pumping Station One), with no formal experience teaching, and I teach embedded programming and electronics at a MakerSpace in my local library. Other volunteers have no formal electronics/coding experience at all. Basically one day I decided to email a librarian and ask if they would welcome a volunteer, and they said yes. That was about 9 months ago. Today, we're forming a partnership with a school, and pretty soon I expect to be volunteering there too :)

    All it takes is one email to start something :)

  • Advanced Circuits is awesome! I remember using them in college, and my teammates and I always saved the popcorn for a late night spent debugging the newly arrived PCB. We used their EDA software (PCB Artist), which worked well and was relatively easy for beginners.

    And like sgrace said, they'll do a single board for a college student (we just told them in the comments when we submitted the order). Which is crazy awesome.

    For anyone comparing Eagle to KiCad, you should know that a number of professional EDA tools separate component and footprint symbols, and having you sync the schematic and layout manually. This can be tricky, but it's nice because you can have one part associated with multiple footprints, and then choose which footprint to use in the layout. My workplace uses Altium Designer, which works very similarly but is much more complex.

    Sparkfun, how many of you use KiCad? Are you switching away from Eagle, or just trying it out?

  • This should only be used with a single-cell Lithium-ion battery. Not a battery pack, and certainly not something as high as 9V.

  • AeroGuy is right. When you buy a thermocouple wire, the "sensing" part is just the very tip where the two metal wires are welded together. So if you cut the tip off, you'll be left with just two metal wires. They can't just be soldered together either. They must be welded together.

    However, you can shorten the thermocouple at the other end, and it will work fine.

  • If you're trying to take this apart, here's my notes:

    Begin by taking the battery cover off. It snaps off at the hinge. Removing the battery cover reveals a screw by the trigger, as well as another screw where the hinge was.

    Remove the two screws.

    There are two grey plastic pieces; one covers the display and keypad, the other covers the front of the "gun" part. Both of them are held in place with plastic tabs (no screws). After they are removed, the two halves of the yellow housing will snap apart (they are also held together with tabs).

    In practice, I was unable to pull off the front one grey piece, so I only took the back one (that covers the display and keypad) off, and then pulled the yellow housing apart carefully, starting at the battery case and working towards the front of the gun.

    Inside of the housing is a single PCB. The microcontroller is under a blister pack, so would be hard to hack. There is a debugging(?) connector with 6 through-hole pins for headers (non-populated), as well as a two-pin header labeled "CAL". There is also an IC labeled "93c466," which may be an EEPROM, but I'm not sure. There is a pushbutton which the trigger hits, and four contacts for the membrane keypad. The display is inside a clear plastic housing, and connects to the PCB via a ZEBRA connector. The IR sensor is in a huge black housing screwed to the PCB (which I didn't take off). The laser pointer is stuck in a mount on top of the IR sensor with some epoxy, and has two wires which are soldered to the PCB. Other than the blister pack, most components on the PCB are 0805 surface mount, so it should be easy if anyone wants to reverse-engineer most of the circuit.

Rotary Encoders

adamj537 12 items

Hardware for three rotary encoders with pushbuttons,...

Temperature Chamber

adamj537 4 items

Parts to build a really small temperature chamber for...