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parallax PIR Sensor (radio shack 276347) — Parallax Forums

parallax PIR Sensor (radio shack 276347)

robertmkmd55robertmkmd55 Posts: 1
edited 2013-10-28 21:40 in General Discussion
Sorry to bother as I'm a total noob at this. My understanding (per discussions and data sheet) is that the output should to HIGH to 5 v (or at least 3+) when connected to 5 v Vcc, and motion is detected. My PIR only goes to 1.67 v?? I'm just connecting it to Vcc of 5v and output directly to an LED which won't obviously light up due to low voltage. Is the part defective? It works ok otherwise? Thanks.

Comments

  • ercoerco Posts: 20,256
    edited 2013-10-28 21:40
    Rev A or B? Rev A says "Note: Driving an external load requires a transistor or MOSFET": http://www.parallax.com/product/910-28027 Rev B may also require external hardware.

    Unless your LED is a low-current 2 mA type, it may be pulling too much current and swamping the sensor output. Disconnect your LED and monitor your sensor output with a DMM or a Stamp input pin to check function.
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