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PointyOintment

Member Since: July 4, 2013

Country: Canada

  • 1.1 W/mK

    That’s presumably watts per meter kelvin, not watts per millikelvin, for anybody who’s not familiar with the specs for this kind of material.

    My understanding of it, which could well be incorrect, is that you divide the contact area in m2 by the thickness in m to get the length value for use in thermal conductivity calculations. For example, if you have a 10 cm square, that’s (0.1 m)2 = 0.01 m2. Then divide that by the thickness, 0.00102 m, to get 9.8 m. Then if you have a temperature difference of 15 K (15 °C), it’s 15 K * 9.8 m * 1.1 W/(m*K) = 161 W.

  • Does anybody have an interesting use for this part that they would like to share?

  • Why is this about four times as expensive (still three times as expensive on clearance, which is how I found it) as the Arduino Pro Mini 328 for what’s effectively the same thing?

  • Probably not too difficult. You’d need a separate switching device (such as a logic level MOSFET) in series with the battery to disconnect it from the load, as well as a resistor voltage divider to scale the battery’s voltage threshold down to the 0.9 V threshold of this detector.

    You would also need some way for it to latch in the off state. I would first try to simply put the voltage detector distal to the MOSFET so it loses power and can’t turn back on. The problem with that is that once it turns off, the MOSFET is undriven and may pass a small current, possibly leading to oscillation (and of course further battery drain). Maybe a bias resistor could work. Or you could put the detector on the proximal side of the MOSFET and short pin 5 to ground so it never charges, but that would consume some (very small, but still there) quiescent current after it’s turned off the battery.

    No guarantees—test it yourself to be sure.

  • You can use a resistor voltage divider to scale your supply voltage down to its detection voltage.

  • GPIOs 7–11 (SDIO) aren’t broken out? Can I not use an SD card in 4-bit mode with this board?

  • If I interpret the datasheet correctly, both. Alternately. And it doesn’t cycle through all colors. I hope I’m reading that graph wrong.

  • According to another commenter, it does now.

  • Export restrictions? It’s just a multimeter! I don’t see why it would have any crypto hardware or anything else restricted.

  • Inventory Day? I thought you stopped doing that years ago.