I wasn't going to run them any place, just stuff everything in a box under the lamp. Air pressure should be the same indoors or out. Humidity will be a little lower indoors, but not a big enough difference to have any effect here. The temperature part... will likely stick with the indoor temperature for this first one. I don't run the heat or AC unless dressing accordingly is of little help. It's really more about changing conditions, not measuring how much of a change.blueroomelectronics said:How are you going to run the data from the sensors? I2C is not terribly fond of long cable lengths.
I have to disagree. Might want to actually do a test of that assumption. I have a guage set of meters for all the above. I can take it from the house to outside and the humidity can vary a LOT.HarveyH42 said:......Humidity will be a little lower indoors, but not a big enough difference to have any effect here. ...
Yeah, I get what yo mean. This isn't going to be something I figure on moving around much or carrying in my pocket. The actually readings for indoor and outdoor humidity will be different, but there should be similar changes. Like right now, it's cold and dry air. Humidity might be a little higher indoors (shower, coffee maker, people/pets), but different than yesterday, which was warmer but wet.mrmonteith said:I have to disagree. Might want to actually do a test of that assumption. I have a guage set of meters for all the above. I can take it from the house to outside and the humidity can vary a LOT.
Think about it. Unless you're fanning doors or have windows open the inside is isolated from the outside. Plus if you're running either A/C or heat it's going to change even more depending on the type of heat.
It will try to even out but it usually takes quite a long time based on how much air flows in and out of the house. If you're dead set on it being inside you could set it on a window sill with a window cracked open to get as close as possible.
I saw something like that when I search for weather related science fair projects. Figured it wouldn't last more then a few days or weeks. My hair is llong enough, fairly strong. My thought was to hook the hair to a light spring, and use the spring for the coil in an oscillator. Stretching the coil should change the frequency. Figured It would be very subtle, an kind of involved getting into a microcontroller. Would be nice to find a cheaper humidity sensor for this project. The one I ordered is $9.90, about twice any other part in the project, so still keeping my eyes open for alternate sensors. Mostly, I want to get something thrown together, just to see if this idea was any good, then work on making it simpler and cheaper. I don't think I get away with just making one or two if it works out.3v0 said:Harvey would not want to use this but others may find the hair hygrometer of interest.
Hair changes length depending on humidity. On more humid days, hair will lengthen.
The diagram below shows a simple hair hygrometer. It takes about a foot of hair to create a sensor but it could be wound around a pulley or two to decrease the length. The pointer could be used to block light between a LED and a photo transistor for sensing.
EDIT: Horse hair can also be used and may be more durable.
The HP01D is the barometric pressure sensor. So looks like I'll need to find another source. Mr. Amp's english isn't too clear on whether or not I'll be getting those two parts, figure it might be a while.Date: Fri 02/29/08 05:13 AM
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Your order is complete, except for HP01D and IDCC10, we are currently following up on these 2 parts with our warehouse. We will fulfill them to your order and keep you updated as soon as they become available.
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Do what I do... Register with Freescale, and blag some freebies.. Plenty of pressure sensors to choose from..HarveyH42 said:Just got this from Futurlec:
The HP01D is the barometric pressure sensor. So looks like I'll need to find another source. Mr. Amp's english isn't too clear on whether or not I'll be getting those two parts, figure it might be a while.