aj

Member Since: September 26, 2009

Country: United States

Profile

Bio

I was an Electrical Engineering student at Purdue University. Now I’m a software engineer at Dwyer Instruments, Inc.

Role

Manufacturing Software Engineer

Organizations

Dwyer Instruments, Inc.

Spoken Languages

English

Programming Languages

ANSI C, Assembly

Universities

Purdue University

  • News - Fluke Responds to Tradema… | last month

    Amazing! Good to see two companies work together. Also, I love the idea of an open-source multimeter!

  • Product COM-08636 | about 2 months ago

    Fifthed. A 16-bit ADC would be a nice addition to Sparkfun’s catalog.

  • News - The Science of Licking a … | about 3 months ago

    It is very dangerous to touch any high-voltage wire. Never use the back, or front, of your hand to test for a live wire. Instead of your body, use a multimeter (and make sure it’s rated for the type of voltages you’re working with).

    Rules (1), (2), and (3) are really good though.

  • Product BOB-09822 | about 8 months ago

    Kudos to you for replying to a two-year old comment! I meant my remarks as sort of a clarification to others who read comments (and didn’t realize there was a customer involved who would dictate communication methods). Perhaps you’re right about the jumper.

  • Product BOB-09822 | about 8 months ago

    Most commercial USB-to-RS-485 adapters are built with the /RE and DE connected, since RS-485 is half-duplex (you can either send or receive, but never both at the same time). This allows a single pin of a microcontroller (or the TXDEN pin of an FTDI chip) to control both receive and transmit enables at the same time. Wiring the adapter so both the transmitter and receiver are enabled at the same time will cause any characters transmitted to be “echoed” back, which is only desirable for custom applications where software can distinguish between an echo and a response from another device.

    If bus contention is an issue, try using a protocol where each device has a unique address, a “master” device transmits to the other “slave” devices, and then each slave transmits after a fixed time interval multiplied by their address…so no one talks at the same time. If you truly need full duplex communication, consider using two RS-485 transceivers (and four wires).

  • Product ROB-10398 | about 10 months ago

    You can power this pump (or any motor) with an arduino and a transistor or relay. Sparkfun’s tutorials should cover that.

    If you hook this pump to a sealed container, it will produce varying pressure by varying the time that it is on. If you hook this pump to a leaky container, it will produce varying pressure by varying the speed of the pump’s motor. Use pulse-width modulation to change the pump’s speed. Do not use pulse-width modulation with a mechanical relay, or the relay will break.

    To regulate the pressure, use a pressure sensor to tell the arduino when to turn the pump on or off. If you want to be accurate, try to find a sealed container, and pressurize it using the “leaky” method. Use the “sealed” method to fill a balloon or in cases where the actual pressure really doesn’t matter.

  • Product ROB-10398 | about 10 months ago

    If you hook this pump to a sealed container, it will produce varying pressure by varying the time that voltage is applied to it. Placing too low (or too high) of a voltage on any motor, including a pump, may damage it.

    However, you can also hook this pump to a leaky container, and it will produce varying pressure by varying the speed of the pump’s motor. You can use PWM (pulse-width modulation) of the voltage to change the pump’s speed (an arduino has PWM libraries).

  • News - Hygrometers: A Cautionary… | about a year ago

    Where did you learn that?

  • News - Free EAGLE Webinars | about a year ago

    Do any of you use KiCad? My employer uses Altium Designer, and I’ve begun playing with KiCad since it has some similarity and is open source. If you have used it, I’d be curious to know your impressions, especially compared to Eagle.

  • Product TOL-10892 | about a year ago

    Some things to note when purchasing a multimeter:

    • Electrical equipment can be dangerous. Before buying any meter, make sure it has a safety approval appropriate for what you’ll be using it for. For example, a Fluke 117 has approvals from UL, CE, several other organizations, has an IP42 dust and water rating, and is approved for CAT III hazardous environments.

    • This is not a True RMS meter. It will not produce accurate current readings in certain situations. For more information, see this helpful App note from Fluke and Newark.

    • If communication interfaces (USB, RS-232) are not isolated, they could damage your computer by connecting them to whatever you’re measuring. Non-isolated equipment can also have erroneous readings when “extra” current leaks between the meter into the computer.

    For more information, check out Fluke’s ABC’s of DMMs.

Name Pieces Total
Temperature Chamber
Parts to build a really small temperature chamber for ex…
7 53.65