Cheap USB analog interface?

On a sunny day (Sun, 3 Jul 2011 02:35:38 -0700 (PDT)) it happened " snipped-for-privacy@fonz.dk" wrote in :

But for that sort of money you can buy a WAP54, it has a hidden serial port too, runs Linux, and can be used for many otehr fun things.

d.

one: (928)428-4073

For the wireless USB stuff, I would look at one of the TI ez430s. They start around 50 bucks.

Here is a power meter built with one.

The cheapest wireless "standard" interface would be Zigbee. A serial Zigbee interface is

This $29 microchip module looks intriguing

Cheers

You can also ZigBee or BlueTooth. Actually, i have a board with a PIC24/PIC32 and MRF24 drafted (first prototype), but haven't done much with it yet, However, all these protocols (WF, ZB and BT) are too complicated. I want/need a protocol that is simple and reliable, non- blocking no matter what. One possibility is just toggle the TX with Morse code. I don't really need RX.

By far, the cheapest/easiest solution is to buy a BlueLine wireless power monitor...or one of the clones from Black&Decker etc. Cost about $25 on ebay or $15 at garage sales/swapmeets. It watches the wheel go around or the blinking light on digital meters. They also have a computer interface, but it's substantially more money.

If you have a digital meter with a light, it's trivial to write a program for a 25-cent PalmIII to watch the light and log/graph the data. I'd planned to update the code to a newer palm with bluetooth for wirelessness. But, I found that, after a few days of monitoring, the new wears off and the desire for fancier features wanes.

Once you figger out where the power is going, you do what you can to mitigate it and you're done. Doesn't do much good to monitor it if there's nothing more you're willing to do about it. You don't need data to know to take shorter showers or turn down the heat.

The blueline tells you what you need to know and has some resale value when you're done.

d.

one: (928)428-4073

The Kill-A-Watt has been hacked to do this.

Both are using gas, so it does not save on electricity. My electricity is 4x more expensive than gas. We just have to use more gas stove/grill than the electric oven.

problem with a killawatt is that you measure what you can plug in. The things that take the most power are hard wired, or 220V split across 2 phases...at least in the good ole USA.

But the metrology problem is the same. If you aren't using it, turn it off. If you're not willing to turn it off, it don't matter how much instantaneous power is being monitored, databased, graphed, displayed, studied...just don't matter if you ain't gonna take some action.

I try not to ask questions if the/my future is independent of the answer.

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end.

phone: (928)428-4073

You don't want to neglect duty cycle in your analysis. A low power item run 24 and 7 can use a lot of electricity. Further, the thing you can control tend to be low power. For instance, you could use an intel atom for your server rather than sold old PC. Old computers are no bargain. They have low efficiency power supplies. The larger geometry chips use more power than the newer cores, provided they have some power management.

One of the shockers in home energy use is the stupid cable box. Some are 40 watts. If you turn them off, it takes the head end a while to see your box and bless it.

My 220V stuff, (oven and dryer), pretty much use what they use. I can't do much to make them more efficient. The washer is a f-ing Maytag Neptune. Low power and low water use, but a crappy washer.

While we are at it, I hope you saw that report about Energy Star products not really tested by the government. You just declare the product to be energy efficient, and you get your star.

Yes, but you can determine that in any number of ways. A KillAWatt is a great tool to have around for about a week. Once you determine consumption, you don't need to track it continuously.

I think I spend more for batteries for all my power and temperature monitors than I save by having current data.

My VCR clock resets on power outage, so I pay the price to leave it running...at least in fall when there's something on tv to watch.

Haven't done Energy Star since '94, but from what I'm reading that's changing big-time. Third party certification is/will soon be required. That's gonna make the costs go WAY up. So we pay for increased product price to get the piece of paper that confirms less energy use. Can't win...

There's a lot you can do to minimize energy usage. Problem is that most people don't want to live like wilderness campers to do it.

When you're paying $70/month for the ability to tweet your every emotion while driving the SUV to get to that $200 "gaga" concert, it seems pointless to shave a minute off your shower.

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You keep bringing up the shower. Are you using electric water heater? If so, switch to gas heater, it saves electricity.

So does a water heater timer. Gas is the most expensive way to heat water around here, since there is no natural gas service.

No one gives a damn what you're doing so don't waste the $70/month, or the $200 on a gimmick performer.

heat

I guess it depends on the area. For us (S. Cal), electricity is 4x more expensive than gas in equivalent energy. Nuclear (electric power plant) is supposed to be cheap, but not when it gets to the customer.

Propane is very expensive around here. Electricity is generated by nuclear or natural gas

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Yes, i do mean natural gas for our area. Nuclear is expensive, after all those environmental costs and political contributions to keep it running.

Another idea:

Like I said, Propane is the only gas availible to local home owners, and it's the most expensive energy in this area.