I would have agreed with you Ralph about 2 years ago, but Matt M. showed me the error of my ways :). Take a look at the SMD tech available - http://en.wikipedia.org/wiki/Surface-mount_technology 2512 is as big as a normal PTH. Once you place your components, 5 minutes in a cheap toaster oven...
Not yet. circuit building tends to be a winter activity. Too much fun to have in the summer! Also, it depends on the features. I tend to drop the features that really aren't well used.
Frankly, I screw up more PTH than SMD boards when soldering. Not sure why we haven't moved to SMD yet...
I haven't been on in a few months, but I was researching how to calculate cumulative temps for pasteurization in my sous vide system, and I found the mother load of info regarding thermocouple design.
I'd start with this excellent video...
Ok, so if the ADC permits the input of 0-1023 to measure 0-5V, what do the Y axis values mean in this graph? I assume I'm seeing the voltage measured in ADC values? And the Mavericks are positive temperature coefficient thermoresistors?
Nevermind - I figured it out.
On a related note, I was...
Ok, here is the debug output.... how do I interpret it?
It does look a heck of a lot smoother than your graph, just from my uninformed review.
[ED: Added new graph later]
Later, I've recorded a busier graph:
I'm seeing a graph that is very smooth, measuring ambient air temp. The house heater was turned off.
What do you have radiating at your place? 200 Watts of Transmitter? (ed: sorry for the snark)
Does it make sense for you to test an alternate design at your place?
Can you point me to the post where you show how do load/run your debug mode? I'd like to do the test with my SMD design and see if i can replicate it. I'm guessing that designing the AVR chip so that the temp analog traces are as close as possible to the thermoresister plugs would be helpful.
If I can recommend this - definitely go digital and avoid the issues (as you are currently experiencing) with analog. You do away with many hardware complexities. If you do a search on the net, you can see that most thermocouple implementations don't select the analog route...
I'm debating adding a capacitance set of switches to drive the HM inputs. Would mount the capacitance sensors on the inside of the case.
This looks interesting: http://www.atmel.com/Images/Atmel-9524-AT42-QTouch-BSW-AT42QT1040_Datasheet.pdf