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31  Using Arduino / General Electronics / Re: Single-wire 24VAC input to Arduino on: December 04, 2013, 06:42:26 pm
John -- that IC won't work.  You don't have AC hot and neutral at the thermostat, you only have hot.  You can't ever directly measure an isolated voltage with only one wire.  The best you can hope for is inductive, but 24vAC control lines are very low-current.  You would have to use a sensitive inductive meter...

Although I would not connect it at the thermostat myself but rather at the furnace, that should be possible anyway.  It is normal to have a 5 or 6 wire 'thermostat cable' in place even when not all conductors are used.  If not a blue 'ground' (actually just one side of the isolation transformer) already there and connected (in mine it is) there's most likely a conductor you can connect up.  That should be true of any house built since the 60's and certainly one that has A/C (OP didn't mention that though and I realize zone valves are a radiant hot water component).

I had to resort to that when I recently added a 24VAC-powered wi-fi thermostat and needed an always-hot 'C' wire as they call it -- I used one of the unused wires in the bundle.
32  Using Arduino / Project Guidance / Re: Yes all i keep getting is Board at COM1 is not available on: December 04, 2013, 05:27:39 pm
Look in the Arduino/drivers folder on your computer (wherever it was you installed the Arduino IDE software).  Install the USB driver in there and you will be able to connect with your Arduino board.
33  Using Arduino / Sensors / Re: Connect a sensor chip on: December 04, 2013, 05:12:11 pm
The most practical way to connect a surface-mount IC to an Arduino is to buy it mounted on a breakout board:

But is possible connect without it. Connecting the capacitators on the breadboard an connect the chip with a cable.

The determinator is whether the pins on the chip match up with the board's contact matrix (it probably won't).  It will be much simpler to buy a prototyping board like and as Johnwasser alluded, mount a breakout board with the chip on it.  Then attach to the Arduino.
34  Using Arduino / General Electronics / Re: SMD Soldering Training PCBs on: December 04, 2013, 05:03:26 pm

I do NOT miss the days of RubyLith films and exacto knives OR the spray resist and ferric chloride.  Praise be the PCB jobbers.
35  Using Arduino / General Electronics / Re: Single-wire 24VAC input to Arduino on: December 04, 2013, 04:57:13 pm
I used some Fairchild MID400 chips, which are designed exactly for this kind of application.  Works great!  They are opto-isolators and can handle up to around 250 VAC on the input side, as I recall.
That looks great! Probably means ordering it, unless the local (small) RadioShack has them or something equivalent. Which sucks, because I was hoping to be logging data by the weekend (and shipping things to Alaska takes time). Can this be hooked up in series with the line to the zone valve, or do I have to do this in parallel and still have the issue of figuring out how to ground it?

You would connect to the switched side of the thermostat, so the MID400 'sees' 24V whenever the thermostat completes its circuit.  In effect, you are illuminating an LED inside the MID400 and this causes the output side's photosensor to switch the 5V signal.
36  Using Arduino / General Electronics / Re: Single-wire 24VAC input to Arduino on: December 04, 2013, 03:06:20 pm
I used some Fairchild MID400 chips, which are designed exactly for this kind of application.  Works great!  They are opto-isolators and can handle up to around 250 VAC on the input side, as I recall.

37  Using Arduino / Project Guidance / Re: Something to hold the light bulbs on: December 03, 2013, 09:07:56 pm
You could use the caps from bottled water, toothpaste as 'sockets' or maybe grab up some glass ball Christmas ornaments in a few weeks then they get deeply discounted.
38  Using Arduino / Sensors / Re: Help me..nRF24L01 2.4GHz Radio/Wireless Transceivers on: December 03, 2013, 07:46:06 pm
Could you try reformatting the code with indentedbrackets and putting it in code tags so it's more easily read? 

Now, on to the matter at hand.  There's the radio.printDetails() function which will give some idea of what the radio is doing.  Have a look at that.  If the values printed are mostly zeros or ones, then the radio is clearly not communicating with the Arduino.  That's where I'd start to figure this out.
39  Using Arduino / Microcontrollers / Re: Trying to use avrdude.exe but window closes imediately on: December 03, 2013, 07:41:47 pm
console apps typically will give you that 'help' display when you omit the minimum required (or provide invalid) command line parameters.

So it sounds like you just need to supply the -t option and the name of a configuration file (based on what I see when I tried to run it myself.
40  Using Arduino / Project Guidance / Re: Advice needed to buy an enclosure on: December 03, 2013, 07:35:40 pm
If this is going to be out in plain sight, then maybe something like a jewelry box?

$10 and pretty swank.
41  Using Arduino / Project Guidance / Re: Arduino Micro green light constantly flashes !help! on: November 29, 2013, 01:35:10 pm
Did you install the USB driver provided with the Arduino IDE?  Sounds like you may not have.

Look in C:\Program Files (x86)\Arduino\drivers (or wherever the equivalent is for your situation)
42  Using Arduino / Microcontrollers / Re: Is this mega2560 a fake? on: November 29, 2013, 09:53:15 am

No, not the infinity logo with the + and - signs --- the big-ass circular gear-like thingy that only partly fits on the back of the board...

Oh, yeah... Guess my excuse is I don't look at the bottom side very often.  smiley-wink
43  Using Arduino / Project Guidance / Re: 100 Year Long Tone? on: November 29, 2013, 09:45:01 am
Somebody's going to smash the speaker LONG before 100 years is up.  smiley-lol
44  Using Arduino / Sensors / Re: How to make a sensor / potentiometer using a metal / iron ball on: November 28, 2013, 06:08:28 pm
Another option would be to wrap the nichrome with a small airgap between turns around a form to put more resistance in the circuit.   You can wrap the nichrome simultaneously with some other wire to act as a spacer and then remove the spacer.

Perhaps the better solution would be to utilize an opamp to read the voltage divider at very low current and drive the Arduino with the opamp output?
45  Using Arduino / General Electronics / Re: nRF24L01+ w/ external antenna: need separate 3.3VDC regulator, or use 5VDC? on: November 28, 2013, 05:36:33 pm
I bought some of these awhile back:  They come in handy with the nRF24's.  I just with they'd install the pins *down* instead of *up*.  Matches the pin spacings on breadboards and protoboards.
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