I am attempting my first ever Arduino project ... it is going to be fairly simple. The plan is just to have a program that will stream live thermocouple data to a computer over wi-fi.
My biggest question is what hardware would be best for this? I assume a wifi shield, but I'm not sure about which arduino to get or which thermocouple shield.
Suggestions?
Thanks in advance.
This is not a simple project.
Start by getting an Arduino and working your way through some of the simple examples, so that you understand the special tricks needed to work with such an incredibly limited computer.
Get a thermocouple and amplifier breakout and learn to use it to measure temperatures.
Then get a wifi shield and learn how to connect to your network and send data.
Finally, combine the latter two.
Thank you for your response.
While this is my first Arduino project, I do have a lot of experience with data acquisiton, control, etc. Just using different hardware.
I'm mainly looking for suggestions on what the best Arduino hardware to buy would be. After a little more research I'm thinking about using the Yun, but haven't found a thermocouple shield I'm satisfied with yet.
Obviously the shield would digitize directly so I don't need to run the thermocouple through an amplifier and ideally would have an internal CJC.
Hi,
What is the application, what is the temperature range you are measuring?
Thanks.. Tom... 
Application is basically monitor soil temperature at multiple locations. I'll be using J type thermocouples... and in the temperature range that they are mostly linear.
Sample rate is going to be very slow. Number of channels of more important than precision. Ideally it would be 16 with a multiplexer, but best I've found so far is 8
FWIW, I've never seen an Arduino thermocouple shield. Arduino's aren't meant for industrial applications so why would someone invest the time to create a shield for industrial sensors? Just saying...
I'll also say that IMO, using a thermocouple to measure soil temperature is just shear madness. A type J thermocouple, while it may be relatively linear over a small range between 25 and 50 degrees C, the resolution will be at best one degree if you're very lucky but the voltage span you're trying to resolve is in the microvolts range. That's not a hobbyist project.
There are lots of other options and a thermocouple would be my LAST choice for an Arduino application. Have you looked at the Dallas/Maxim 18B20 sensors? Dead simple to interface and available in encapsulated forms with wires attached for a few dollars. Heck, you can't buy a thermocouple for that and you haven't even looked at the cost of conversion to digital.
A MAX6675 shield works fine, with a resolution of 1/4 C
Allan
Hi,
If you are only looking between 0 to 100C, Dallas/Maxim 18B20 sensors would be easier, noise supression wise.
Tom...
I agree that something like the Maxim 18B20 would be far easier than a thermocouple for this project.
You could interface it easily to a ESP8266 e.g. this one and get wiFi thrown in for free.
Hi,
You can even get them in waterproof case and leads.
Tom...
The most bang for your buck would be a NodeMCU with a DS18B20.
Thank you all for taking the time to respond.
This isn't an industrial application... it is a gift for my father so he can monitor the temperature in his garden.
Do you all really think that small, easily damaged independent sensors attached to easily damaged wifi controllers would be easier for him than simple thermocouple wire? To shove in dirt? I'm not worried about saving $5... I'm worried about ease of use. (which, by the way, J type thermocouple wire is cheap)
Oh, and here is a thermocouple shield for the Arduino. I guess there is a desire for "madness" Now you've seen one.
BowenM:
Do you all really think that small, easily damaged independent sensors attached to easily damaged wifi controllers would be easier for him than simple thermocouple wire? To shove in dirt?
Thermoucouple wires just shoved in dirt will very soon disintegrate unless they are shielded in a waterproof casing.
The sensors suggested by @Tom are already protected. You can get them on eBay direct from China for a couple of pounds/dollars