If you want to go the TC4 route, you can now buy fully assembled and tested ones for $50+shipping
http://www.mlgp-llc.com/arduino/public/arduino-pcb.html

Add in an arduino and a little case, which is the min. required, and it would be a little under $100.
If you bought a kit, with the hard to solder surface mount parts installed, you would save $20

You would need a PC/USB to power it the arduino/tc4, and use the PC to read out the and chart the data.

For around $30 more, you could add the LCD adapter, and buy an LCD to display the data without a PC.

Add $5 to get a wallwart to power it, and you wouldn't need a PC, it could work standalone.

And, as Mark talked about, I have a bluetooth interface added into my setup, which is more money and a little more work, but it is cool to have

Randy

Randy, okay, this is starting to make a little more sense 50+6 for the TC4, and 31 + ? for the uno. I am missing how to connect those 2 boards together. Glue???

I will power it with the PC - is there software to store and plot the data?

Also, how frequently can you poll it? 1 sec?

Thanks! The big thing with this is that I can monitor 4 tc's...

No glue required. The TC4 is a daughter-board that plugs into the Arduino board.

Kristi wrote:I will power it with the PC - is there software to store and plot the data?

Also, how frequently can you poll it? 1 sec?

Thanks! The big thing with this is that I can monitor 4 tc's...

There is a basic software application (called Bourbon) that logs and plots two temperature channels. It also logs the rate-of-change of both temperatures, and plots one of them. Sample plot is below.

Although this application was written to accept up to 4 channels of input, it would still require some tweaks to the (open) source. The PC side of the application is written in Processing which is very similar to Java. The Arduino side is essentially C++.

If you want the highest resolution setting on the ADC (which is probably the case for measuring shot temperatures), each channel is going to require around 300ms to convert a sample. So two channels works fine on a 1 second cycle. Four channels will probably require 1.5 or 2.0 second sampling period.

Right now, the roasting applications (except the one for Artisan) do not work on polling. Instead, the Arduino just streams data over the serial line and it is up to the PC application to read it as it comes. It would be pretty simple to use polling instead if that better suited your requirements.

If you decide to go this route, I'll make sure there is software to support what you want to do. I've been waiting for a good reason to build a 4-channel application

Jim

JimG wrote:If you decide to go this route, I'll make sure there is software to support what you want to do. I've been waiting for a good reason to build a 4-channel application

Jim

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huge thanks for that!

So there's $100 between me and that, so it won't happen this month - not sure about next - I've already been spending a lot on espresso (2 tamper bases, toroid, 2 other pitchers, convert Macap to stepless, replace E61 rods, 4 different steam tips, naked pf, etc...) I also first want to see what I can control, taste-wise, by monitoring the external nose temp while flushing and pulling...

First attempt was good. At 1.3bar, I have to surf and wait (first try was 10sec and 20sec, then wait for it to drift down to 200), at 1.2bar, I can stumble blindly up to the machine and get chocolate, but can't froth milk! LOL

So this will go quiet for a bit, but I'm sure I'll be back. I need to be educated!

I've been using RoasterThing (formerely BehmorThing) software to plot my roast profiles, manage my inventory, and remind me of cleaning cycles and have a prototype 2 channel USB thermocouple interface that works well for me. I started with BehmorThing in 2009 with my Behmor and the software has really grown a lot since then, becoming now a more roaster agnostic package.

You may want to check it out as they're getting to release an I/O board that includes 2 channel USB thermocouple inputs as well as some control outputs that will integrate with the roasting software. The roasting software is a free download so you can check it out even without the board and see if you think this is something you'd be interested in. I don't know a firm release date or price, but you could watch the site for this.

I've asked to be put on the list for one of these control boards once it's released. I do not financially benefit from RoasterThing for posting this, I'm a fan of the software and have donated to its development.

Well, impatience got the better of me, so I ordered a 1 chan usb monitor w 3mm probe (fleabay, Canada), and another adapter from Eric. (first one is on the Bric which is still with Peter.) Definitely needing this!!! Though, shot in the dark, I pulled a nice one this eve, even though the nose only said 197. Go figure. And when Anita is at 1.3 bar, she microfoams beautifully.