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adamj537

Member Since: September 26, 2009

Country: United States

Profile

Bio

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.

Role

Software Engineer

Organizations

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

Spoken Languages

English

Programming Languages

ANSI C, Assembly, C#

Universities

Purdue University

  • 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.

  • Really cool project!

  • That. Is. Awesome.

  • The version of this board I received has solder jumpers which connect CLR to VCC and connect EN to GND. Is that a newer version of this product? If so, could we have an updated schematic and product photos?

  • How about an open-source touch-free faucet that monitors and/or displays temperature and flow? With RFID toothbrush activation. Have you ever tried to brush your teeth with a touch-free faucet? It’s an exercise in futility.

    Could there be an IoT potty-training device? Or a project to train people to shower in less time? Or a project to train people to wash their hands correctly?

    Or a medicine cabinet which prevents children from poisoning themselves and/or helps people remember their medication and/or keeps track of when stuff expires. Creative displays involving the mirror itself would be a plus…

Temperature Chamber

adamj537 4 items

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

Rotary Encoders

adamj537 12 items

Hardware for three rotary encoders with pushbuttons,...