Wow,
Fantastic board you guys!
I got more help here in 24hrs than the combined efforts of two weeks worth of probing elsewhere.
Cheapslider. I'd like nothing better than to cannibalize an off the shelf room thermometer with remote sending unit. Indeed they are plentifully available. I'm not trying to do anything so noble as educate myself to circuit design - if I can help it. But they are all LCD. The project I'm working on uses red led meters already on its panel. I'd like to keep things consistant.
I've actually already tried LCDs for this and am sorely disappointed with their visibility, even the backlit ones (in comparison with the LED versions). LCDs are just so much easier on batteries in inexpensive room thermometers that LEDs are all but non existant in these devices anymore.
Jeff, I'm a complete novice with circuit design/analysis. I followed the last link you provided and do I understand correctly there are forty something components to that project? I'm just trying to be a little rational. If I can wire together the DPM that I linked in the first post to an LM34 with just a couple of connections and get within a couple of degrees accuracy, that's time well spent and I'll feel like I accomplished something.
My needs are for monitoring gross changes in temp between in/out on a water cooling loop. I'd like to take advantage of inexpensive readily available parts like the DPM I linked to and the LM34. Otherwise, I can simply purchase a pair of CyberDyne LED dash mounted water temp gauges with senders from Summit Racing online for about 110 USD. An eight dollar display along with a six dollar sender - wired together for me for 55 dollars - and I can't crack that mystery myself without an EE degree. Guess that goes right to the heart of my frustration.
Until I googled it a while back, I would have guessed that LED DPM thermometers would be as common as light bulbs. A digital display of fluid temp. Isn't this a somewhat fundamental and common need for an experimenter or hobbyist? LCDs suck for visibility by comparison - at least in this smaller form. And the affordable LCD aquarium and computer bay thermometers available are of breathtakingly poor quality - (i tried them).
Where ever I've asked about affordable panel thermometers it's as if I were inquiring into the grander mysteries of ghost particles in the universe. I'm just knocked out by this really. Why hasn't this been done a million times, by a million people, and documented at least dozens of times. Why don't parts suppliers have LED DPMs and transducers available cross-referenced with basic instructions for the most common applications - such as temperature or PSI?
Hasn't anyone else out there come across a situation where you were astonished by it's obscurity? Like, say, going to the hardware store for sandpaper and having the clerk stare blankly and call for assistance? The assistance comes and the guy says "yeah, we used to use that stuff at a shop I worked in. Like beach sand glued to hard paper - yeah I think that's the stuff. Haven't seen it around these parts. Have you looked online?"