Last tests…

This evening I started building the first ELV PIR13 based motion sensor. Looking at the time right now, I think it took me 2.5 hours; during that time I soldered a JeeNode, attached a cable to the PIR13, soldered a XBee breakout board, soldered the wires to the JeeNode, drilled some holes in the enclosures,  … well here’s the result:

Almost finished

With each sensor that I build, it’s becoming less time consuming to build the hardware. With the sketch compiled and uploaded in debug mode, i wanted to see if everything was working OK, and it did. One last thing has to be resolved before i can move this sensor to it’s final location, and that’s if I can enable the internal pull-up on the interrupt pin. I probably can,  but maybe that’s not such a good idea. I mean, a pull-up resistor consumes power, so it matters if it’s 100 Ω or 100 kΩ, right? What if the resistor can have a higher resistance (and the PIR still working well) than the internal pull-up? Would that save me energy? And how much? An issue to spend the next evening with, cause this is all to new for me to decide based on experience or knowledge…

So that’s why i added a header on JeeNode port 2 (click the image and you’ll get a more detailed view) and put a resistor in there, between P and I; so I don’t have to rely on the internal pull-up if I don’t want to but can also discard that external resistor – based on what I think is best based on my findings.

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One Response to Last tests…

  1. Pingback: Notes about the pull-up

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