Recent content by dementeddigital

Thanks for this.  I get so many robocalls, it's really making me angry.  My number was on their list.   I ended up changing my outgoing voicemail message to this:   https://www.youtube.com/watch?v=2BVbyCZXc5s   and I dump every unknown call to voicemail.  It doesn't seem to help, though.    I'd...

  I don't see a lot going on in the controller market.  There seems to have been a push for some cloud-based control, but I think that's cooled off a bit.  I would bet that the next big push will be from Google Home, Amazon's Alexa, and Apple's Homepod to be the center of the controlled home. ...

  That's impressive!  Your house must be well insulated.  Where does the Omni get the daily high temp information?  You did most (all?) of the programming for that cooling logic in the Omni?

  I have the same issue.  I have cameras on my driveway, front door, and looking out from the house in every direction.  I have motion sensing set up to send me emails with images.  I have lots of trees, and these cast moving shadows when the wind blows, so I get lots of emailed pictures of...

I had a trained German Shepherd.  He was great for telling me that there was a raccoon in the back yard at 4AM.  (Ugh...)  He was very humble, but he would attack ferociously on command.  I never worried when my wife would go on a run.  I miss him quite a bit.   Is it possible to just have an...

  That looks like a fun project.  I need to make a serial interface between the Omni for both my stereo receiver and HDMI switcher.  I was just going to trigger them with ASCII strings sent to an Arduino on a spare serial port, but this looks more elegant.

I don't see a power supply in the router, but I would assume that it only takes 5V in from an external source.  I was thinking that you might open the automotive power supply to see if that one has a switching regulator.  I bet that it does, and you're probably OK with using it.  POE works, too...

  In order to read current, you need to put your meter in series with the circuit.  On the "current" setting of your meter, it's going to look like a short, and if you touch the probes across the connections (instead of in series with them) then it will crash the 12V aux power rail.  You might...

  Pete, some of those automotive adapters use switching regulators instead of linear regulators.  The switching ones are generally very efficient.   You can crack it open and have a look to see which kind it uses.

  What was connected to the Arduino?   The regulator on the Arduino is a TI LP2985.  Just doing some rough numbers at 12V in, we're dropping 8.7V across the regulator.  The thermal impedance is listed at 169 deg C per watt, and the max junction temp is 125 degrees C.  Let's assume that ambient...

Excessive current draw on the Omni isn't likely to damage the Arduino, though.  It would just drag down the +12V aux power rail in the Omni and cause the Arduino to shut down.  It would certainly make the Omni angry, though.   I think that you might still have something else going on there.  ...

I agree with Pete.  Adding up the total current draw is always a good idea, since the panel can only provide 1A total, IIRC.   Since this happened when connecting the USB cable from the minimac to the Arduino (and not when connecting the Arduino to the Omin), I'm suspicious of a ground potential...

A difference in ground potential is certainly one possibility, but it would be helpful to know more about your setup.   When you ran power to the Arduino from the terminal block, did you have some 5V regulator in between them?  I assume yes.   How were the grounds between them referenced?   Was...

Thank you for the thoughtful reply.   I suppose that if something is listed, then the NRTL has looked at the circuit structure and deemed that it is safe (components operating at less than their maximum ratings, etc.)  I worked for a fire alarm manufacturer almost 20 years ago as a design...

What are the things that experienced security people look for when they look at a new panel?  How do you make a determination whether or not it was well designed and is a "good" unit?  Presumably, all are not created equal.   From a hardware perspective, things like operating voltage range, EMC...