Hi, I'm building a set of MotionMote's for occupany sensing of meeting enclaves. They are just prototypes, so I'm not using the MotionMote kit, rather just hooking up the PIR and the Moteino together running on a 9V battery. On the blog that talks about the kit, Felix removes the diode and regulator on the PIR. My question is - if I don't use the kit, and just want to run off the 9Volt directly to the PIR / Moteino, should I still remove and bridge the diode / regulator on the PIR..
For example, if I'm connecting the PIR to VIN and GND on the Moteino, I expect the reference voltage to be 9V since that's right from the battery - if I don't have the regulator on the PIR is that bad? And if I DO remove the regulator, should I just hook up the PIR to the 3.3V pin on the moteino?
Thanks.
Do not hook up the PIR to 9v without its regulator. You will fry it. The regulator on it allows a very large input voltage but it's also not really efficient, but it's not too bad either.
I used to use PIRs unmodified and you can get several months of service on a 9V if you code the Moteino the right way.
You can try the PIR powered from the moteino "3.3V" pin, that should work and should be more efficient, there's not only 1 regulator in the eq. - the Moteino regulator which was cherry picked because it's very efficient, has low dropout/noise even though it's linear (vs a switching one).
I hope i've answered your Q.