Hi, guys, I’m a total noob and was hoping to get some suggestions from the forum. I got an Acurite Humidity Monitor
http://www.amazon.com/gp/product/B0013B … bw_g201_i1
and I want to mod it so that I can send its reading to a web server using a wifi module or XBee.
Can I get any ideas? This is what the Acurite looks like inside:
http://oi62.tinypic.com/2wh44ty.jpg
Is this even possible?
Thanks
dan
It is certainly possible, but it would take a lot of effort. The manufacturer won’t tell you how the sensor works.
Much easier to buy and use a humidity sensor that comes with a data sheet and possibly even example code.
That seems to be a resistive type of relative humidity sensor, as it is called R7(RH) on the pcb. It also seems to make a voltage divider with R5(RT), which would suggest that this takes care of temperature compensation in some way. Likely some of the other resistor components and the capacitor C1 could be part of the circuit for signal conditioning. But may also be debouncing circuitry for that C(elsius)/F(arad) switch pad. You would have to follow all traces until it goes into the black blob, to the positive end of the battery, and to the negative end of the battery and reverse engineer the circuit. Hopefully it is just one trace that goes into the blob, and that would be the analog signal which the Xbee analog input could pick up. You’ll have a the display on the other side to make sense of the relation ship between resistance/voltage values and humidity and temperature result. But attaching an additional other analog input/ADC of the Xbee to it might load the voltage divider too much and distort the readings. Getting a reading is one thing, making sense of it is entirely another. Calibration will not be easy.
Quite a feat if you succeed in doing that as a total noob. But if you say, “huh?” when you read “voltage divider”, then I say don’t bother with it now. Learn basic electronics first.
Hi guys, thank you for the response. While I didn’t fully go “huh?” at the mention of voltage divider I do think this project is beyond the scope of my experience. I thought it might be nice to ‘sip’ the data while still having a really nice display for a mere $9.89. I won’t give up on the idea of hacking sensor gadgets but for now I think I can get it to work with a simple brakeout board and my personal web server.
@Valen I will return to your response once I know a little bit more and hopefully get it to work in the future.
Thank you
