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Interfacing a digital accelerometer — Parallax Forums

Interfacing a digital accelerometer

servomakerservomaker Posts: 5
edited 2011-04-03 08:21 in BASIC Stamp
I am interfacing a BS2px to a Bosch BMA150 digital accelerometer that runs on 3.3VDC. What value resistor do I need to drop the SPI interface voltages from the BSpx to the BMA150 to protect the BMA150?

Comments

  • FranklinFranklin Posts: 4,747
    edited 2011-04-02 16:08
    There is a really nice article in this months Nuts and Volts about just this topic. A resistor will limit the current delivered but depending on the device may not be what you need.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-04-03 08:21
    This circuit is the panacea for all concerns in this regard:
    3V_5V_mosfet.jpg

    For the MOSFET you can use a VN2222L, a BS170, or a 2N7000.
    It's OK with resistor values in the range of 2K - 10K.
    [It's "patented", that's why there are articles in N&V tippy-toe'ing around it.]
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