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16  Forum 2005-2010 (read only) / Development / Re: LCD shield and/or LCD serial backpack on: February 20, 2008, 03:18:42 pm
Nick, I'm definitely interested in your OpenLCD project.   I started playing around with a 16x2 display last night, starting with the 8 bit interface and then going to 4, and then this morning I was thinking that it should be simple (and cheap) to delegate control to another Arduino chip.  Lo and behold, I stumble upon this thread!  ;D  So, please keep us posted on your progress!  I'd love to see some code in the SF SVN repository... (hint, hint! smiley-wink)
17  Forum 2005-2010 (read only) / Interfacing / Re: Solid-state anemometer on: July 09, 2009, 09:59:16 pm
This might be the mother lode: the Micro Gust Thermal Anemometer.

http://www.gellerlabs.com/MGTA%20kits.htm
and
http://www.nutsvolts.com/index.php?/magazine/article/micro_gust_thermal_anemometer_mgta

It would appear that the LM399 diode is obsolete, and I don't see a replacement. smiley-sad
18  Forum 2005-2010 (read only) / Interfacing / Re: Solid-state anemometer on: April 19, 2009, 05:47:02 pm
Found another link while searching for "thermal anemometer": http://www.fonema.se/anemom/anemom.html
19  Forum 2005-2010 (read only) / Interfacing / Re: Solid-state anemometer on: April 16, 2009, 08:32:57 am
Here's something that builds on the idea, and has a readable schematic: http://electronicdesign.com/Articles/Index.cfm?AD=1&ArticleID=1978, and there's another version by the same author here: http://ww1.microchip.com/downloads/en/AppNotes/91044a.pdf

I'm not able to find that Cyntec se102 thermistor...
20  Forum 2005-2010 (read only) / Interfacing / Re: Solid-state anemometer on: April 16, 2009, 06:00:40 am
Not to be pedantic, but I googled for "solid state anemometer" and found this: http://www.accessmylibrary.com/coms2/summary_0286-9311675_ITM
It looks like it might fit the bill...
21  Forum 2005-2010 (read only) / Interfacing / Re: 1-Wire, DS18B20... How do I search the bus? on: January 31, 2010, 09:12:03 am
What's the physical wiring of your sensors look like?  There are some app-notes from Maxim/Dallas that discuss overall network topology and the limitations you'll run into with wire length, as well as some mitigation strategies.  I don't have the app-note location handy, however.  I ran into similar problems as you when wiring sensors up in my house and ended up having to run two separate networks.  That may be the case for you, as well...
22  Forum 2005-2010 (read only) / Interfacing / Re: 1-Wire, DS18B20... How do I search the bus? on: January 13, 2010, 09:34:24 am
Awesome! Thanks!
23  Forum 2005-2010 (read only) / Interfacing / Re: 1-Wire, DS18B20... How do I search the bus? on: January 13, 2010, 08:17:41 am
Can you update the playground, please?
24  Forum 2005-2010 (read only) / Interfacing / Re: 1-Wire, DS18B20... How do I search the bus? on: March 31, 2009, 06:16:23 am
I got around the problem by using two 1-Wire buses. smiley
25  Forum 2005-2010 (read only) / Interfacing / Re: 1-Wire, DS18B20... How do I search the bus? on: March 31, 2009, 05:39:49 am
What's the bug?  Where's it detailed?  I ran into a problem where I was unable to resolve more than three devices on the bus, but I thought that was due to a poor wiring job on my part (I have DS18B20s running all over my house with some hefty wiring runs).  I was getting CRC errors when scanning the bus.  Is that what's happening here?  I see that the sample code above isn't performing a checksum...
26  Forum 2005-2010 (read only) / Interfacing / Re: HSP12P Humidity Guage on: December 14, 2009, 03:51:10 pm
That looks very similar to the humidity sensors we discussed in this thread:
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1253792412
27  Forum 2005-2010 (read only) / Interfacing / Re: H25K5A: Resistive humidity sensor? on: December 15, 2009, 07:28:49 pm
I know, but thanks for keeping an eye on me. smiley I just thought your post would be helpful to others, and it moved with no forwarding address.

I'm breadboarding my sensor with a 555 timer right this very moment.  Here goes nothin'…
28  Forum 2005-2010 (read only) / Interfacing / Re: H25K5A: Resistive humidity sensor? on: December 15, 2009, 07:11:30 pm
… aaand that helpful blog post has moved to here: http://1024.cjb.net/2009/10/rh-measurement-resistive-avr/ smiley
29  Forum 2005-2010 (read only) / Interfacing / Re: H25K5A: Resistive humidity sensor? on: September 25, 2009, 11:31:16 am
I'm not entirely sure this is relevant, but I bought a handful of HCH-1000 capacitive humidity sensors thinking I'd be able to drive it with DC and a resistor and measure the charge-time directly with the Arduino's ADC.  Then, after seeing this thread, I went back and re-read the datasheet and see that it's the same design as the sensors mentioned in this thread. *grumble*

I've found a number of interesting discussions and thought I might pass them along:
There's a user on electro-tech-online.com named blueroomelectronics who is building a thermostat kit with humidity sensing.  Here are discussions around his kit and adding that functionality.  This is the schematic of the kit; note the fairly simple arrangement of the 555 timer for generating a frequency based on relative humidity and how it's input to the PIC.  This is a presentation from Honeywell that contains several sample circuits, including a couple that appear to output a voltage based on %RH, using a couple of 555s and a pair of op-amps.

The simple frequency-generating 555 circuit looks like the simplest.  What are your thoughts on that one, Mike?
30  Forum 2005-2010 (read only) / Interfacing / Re: SD low-power modes on: October 30, 2009, 02:52:08 pm
It took me a while to track this file down, but I think this might be relevant:

Quote
1.10 Automatic Sleep Mode
A unique feature of the SanDisk MultiMediaCard/RS-MultiMediaCard is automatic
entrance and exit from sleep mode. Upon completion of an operation, the card enters the
sleep mode to conserve power if no further commands are received in less than five
milliseconds (ms). The host does not have to take any action for this to occur. However, in
order to achieve the lowest sleep current, the host needs to shut down its clock to the card.
In most systems, the MultiMediaCard/RS-MultiMediaCard is in sleep mode except when
the host is accessing it, thus conserving power.
When the host is ready to access the card in sleep mode, any command issued to it will
cause it to exit sleep, and respond.

From ProdManRS-MMCv1.3.pdf, which was originally published by SanDisk; it's since 404'd on their site.  
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