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Mark Fickett

Member Since: December 16, 2010

Country: United States

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http://www.markfickett.com/

  • News - Enginursday: The Hormes R… | about 5 days ago

    I don’t think I saw a video link in the article, so: https://www.youtube.com/watch?v=Yz-KQKAffAk .

  • Product ROB-08782 | about a month ago

    I posted a video of a prototype clamp I made with it. It’s handheld and thus kinda shaky, but you can at least see it move.

    I had a 5v source and wanted to make sure I wouldn’t damage the NM / draw too much current if I left it on, so I overcompensated with a 4.7 ohm resistor. If I do my arithmetic right (having measured 5.2 ohms for the NM), that leaves only 2.6v for the NM, which may contribute to its slightly slow response, as compared to Miga’s demo video lifting a fishing weight.

  • Product ROB-08782 | about a month ago

    I made a small clamp using the NanoMuscle for my quadrotor. Pros: Easy to set up (just need on/off). Cons: Short stroke, much slower to respond in sub-freezing temperatures under the rotors' wash. Photos, videos, some more details.

    As others have pointed out, SparkFun’s photo (and what I got in the mail) is the NM706-Super, not the NM70 as the description says / what their datasheet link is for.

  • Product COM-00594 | about 6 months ago

    Photos of output from this and the green laser module. I connected it to 2x NiMH AAs (red to +, white to ground) and got a normal laser-pointer brightness; I measured 3.2v and 16.5mA.

  • Product COM-09906 | about 6 months ago

    Photos comparing this to the red laser card module. I attached it to 3x NiMH AAs (+ to the housing and ground to the spring) and, without adjusting the trimpot, measured 4.2v and 225-230mA. As everyone says, it’s very bright; almost uncomfortable to look at the dot on white surfaces.

  • News - Enginursday - RFID techno… | about 7 months ago

    I made a pill tracker using the ID-12. The idea was to help my mom remember which pills (on various schedules) she’d already taken. The code is on github, and includes a very simple implementation for reading IDs from the ID-12 (using NewSoftSerial, so it doesn’t conflict with the default serial).

  • Product PRT-10217 | about 2 years ago

    Summary:

    • LED bright: charging
    • LED off: complete; or no battery or voltage too low

    And it does stop automatically.

    (I was hoping the comments would tell me, too. Notes below.)


    Summary of the STAT pin on the MCP73831, from table 5-1 on the datasheet. Since the cathode (-) of the LED is connected to the controller, setting the pin low turns the LED on; setting the pin high (or putting it in high-impedence mode) turns the LED off.

    • Shutdown: Hi-Z (High-impdedence mode)
    • No battery present: Hi-Z
    • Preconditioning: L (Low)
    • Constant-Current Fast Charge: L
    • Constant Voltage: L
    • Charge Complete – Standby: H (High)

    From the datasheet, this unit features “AutomaticPower-Down”.

    “”“STAT is an output for connection to an LED for charge status indication. Alternatively, a pull-up resistor can be applied for interfacing to a host microcontroller. STAT is a tri-state logic output on the MCP73831 and an open-drain output on the MCP73832.”“”

    The schematic says it’s the MCP73831. So, it should be tri-state. Further:

    “”“The charge status output of the MCP73831 has three different states: High (H), Low (L), and High-Impedance (Hi-Z). The charge status output of the MCP73832 is open-drain, and, as such, has two different states: Low (L), and High-Impedance (Hi-Z). The charge charge status output can be used to illuminate 1, 2, or tri-color LEDs.”“”

    The schematic shows that it’s connected to a single (single-color) red LED; so it doesn’t make use of the tri-state output.

  • Product SEN-10988 | about 2 years ago

    I don’t see the voltage => ºC equation at hand. So, to save others the trouble:

    The datasheet says 1ºC/10mV, and 750mV @ 25ºC. With V as our independant and ºC as our dependant variable, we can set up a point-slope form: ºC - 25ºC = 1ºC/10mV * (mV - 750mV). Solving and converting to V, I think this gives the formula:

    ºC = 100 * V - 50.

    This checks out with the graph on the datasheet, with 0.3v for -20ºC and 1.2v for 70ºC (158ºF).

    I haven’t tested it yet, but this looks great for working with an Xbee: they should run on the same supply voltage, and expected temperatures should fit within the Xbee’s ADC range (max. 1.2v).

  • Product PRT-09279 | about 2 years ago

    I was hoping for a longer option too (12-pin in my case). However, the extra-long male breakaway headers should do fine as a workaround.

  • Product COM-10312 | about 2 years ago

    I powered one directly, so far (a cople months) without issue. It’s usually 1/3 on (each LED is usually 100% red or 100% green, with some other colors), so I don’t know about the all-white case. It’s connected to an Arduino Uno SMD, which is plugged in via USB to a desktop machine (the motherboard details of which I don’t know). I’m using it as a continuous-integration status light in a paper/plexi enclosure.

No public wish lists :(