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4-channel TC meter and datalogger project
Randy G
Scott-- sounds like you are talking about a fluid-bed roaster. That certainly makes sense. I forget folks still use those... ;)
That's very much a different situation than with a drum roaster.

Life's too short to drink bad coffee.
 
randytsuch
Hi Bill
Cool project.
I've been thinking about trying to replace the PID that I use for roasting with some kind of Arduino or comparable platform, but I'm not sure I want to spend the time required.

I would like two TC's, one for ET and one for BT. I would control the heater with a SSR, cycling it on and off as required to meet the profile. I would also like to control fan power. Ideally, I could manually or automatically control a roast, while recording all the parameters of the roast, so I could recreate the exact roast if I wanted to, or tweak some stuff, and run a modified profile. Not looking for much there Grin

I was also looking a little at this guy
http://www.coffee...ast/482368
It was some thinks already set up, but I was worried it might be limited, and I'm not sure how easy it would be to expand it.

Randy
 
bvwelch
Hi Randy thanks for jumping in!

PID is do-able for sure -- Milowe and others are doing that with Arduinos I think. I'm no expert, but I've done some PID with chips similar to Arduino -- back then I didn't know anything about coffee roasting yet, so I put away PID and started learning to roast manually.

I figured to start with datalogging but PID is likely to follow quickly. -smile
Edited by bvwelch on 05/14/2010 3:29 PM
 
bvwelch
Bluetooth seems expensive, so far as I have seen so far. Like an extra $60 on the Arduino end. I wonder how important it is?
 
Randy G

Quote

bvwelch wrote:
Bluetooth seems expensive, so far as I have seen so far. Like an extra $60 on the Arduino end. I wonder how important it is?

That's too much- USB is dandy and more dependable. I don't mind if my laptop smells of Colombian.. :Clap:

Life's too short to drink bad coffee.
 
bvwelch

Quote

Randy G wrote:
That's too much- USB is dandy and more dependable. I don't mind if my laptop smells of Colombian.. :Clap:


Glad you agree. I'll table wireless for now. I can see a little mini-USB connector mod in your roaster's future. :-)
 
randytsuch

Quote

bvwelch wrote:

Quote

Randy G wrote:
That's too much- USB is dandy and more dependable. I don't mind if my laptop smells of Colombian.. :Clap:


Glad you agree. I'll table wireless for now. I can see a little mini-USB connector mod in your roaster's future. :-)


I agree with USB. Bluetooth is limited range anyway, not sure how far away it will reach.

Right now, I use my laptop with a RS-485 connection to a PID, and a USB connection to a temp meter.

How difficult would it be to emulate a PID's or a meter's USB output?
Other engineer roasters have written programs to read this data, and track/plot it. I use the coffeesnob's program with my meter, and I know of one for Fuji PID's that I would like to try.

Randy
 
bvwelch

Quote

randytsuch wrote:
How difficult would it be to emulate a PID's or a meter's USB output?
Other engineer roasters have written programs to read this data, and track/plot it. I use the coffeesnob's program with my meter, and I know of one for Fuji PID's that I would like to try.
Randy


Sounds like a great idea! Can you send more details or links? thanks!
 
randytsuch
Here is a program that interfaces to a Fuji PID
http://www.home-b...ml#p164744

here's a link to the coffeesnob sw
http://coffeesnob...1236075603

I've seen others, but don't remember where

Randy
 
bvwelch
Thanks Randy. Which meter do you use with the coffeesnob software? Also, does the coffeesnob program display the graphs in real-time during the roast, or is it a post-process?
 
beanflying

Quote

bvwelch wrote:
..... Which meter do you use with the coffeesnob software? Also, does the coffeesnob program display the graphs in real-time during the roast, or is it a post-process?


Andy (owner of CS) sells the meters to suit the software at $89 AUD plus post, it is real time logging during the roast. The meter is a little interesting in that it runs a USB lead that terminates in an IR sensor and must have a corresponding IR LED in the meter. No plugs to get oils or chaff stuck in smile

Also mentioned earlier in the Coffeegeek link was the Silicon Horizons board I have one of those on my bench (have had for over a year) with a view to upgrading my D model Hottop, had a bit of correspondance with Randy G about it at the time. This winter our end it is going to happen but I will get a thread going as I start playing rather than clutter this one up.
Edited by beanflying on 05/14/2010 11:39 PM
My name is Tim and I have a coffee equipment addiction problem smile

Two Hottops - modded
TJ 067 Electric 1kg 5+years old
Insert new 5-8kg Roaster here urgently BBQ grill
 
Randy G

Quote

beanflying wrote:

Andy (owner of CS) sells the meters to suit the software at $89 AUD plus post, it is real time logging during the roast. The meter is a little interesting in that it runs a USB lead that terminates in an IR sensor and must have a corresponding IR LED in the meter. No plugs to get oils or chaff stuck in smile


I have an older Omega HH 506RA that uses an IR link to serial cable... I wonder if the USB cable is the same but with different software? I will have to ask Andy... Or Omega...

Life's too short to drink bad coffee.
 
bvwelch
Good news, the rise-o-meter feature is working well with the boiling water test. I think it is time to turn some beans brown!
 
bvwelch
The rise-o-meter is working pretty well, but the temp reading falls way behind as the roast gets above 350 F.

I need to order another TC probe and maybe some of those chassis-mount jacks so I can quickly switch between my reference handheld meter and the Arduino. -bill
 
randytsuch

Quote

bvwelch wrote:
The rise-o-meter is working pretty well, but the temp reading falls way behind as the roast gets above 350 F.


Wonder why?
What IC did you use for the thermocouple interface?

I have started to seriously think about a similiar project, and was looking at the AD595.

Randy
 
bvwelch
Hi Randy, it is hard to say - could be the flakey TC I was using - bought some cheap 'extension wire' thinking I could make my own TCs. It wasn't designed for this, in fact it began to melt during the roast - ugh.

I may go with the AD595, but I am trying a really cheap 18-bit ADC first. If it works, it will save a ton of money over the AD595, especially if you wanted 4 channels. There are several different cheap ADC chips that could work, but I'm going with I2C parts as much as possible. The first chip I am testing is the MCP3424. It may take a few iterations before we find the best (cheapest) solution. But nothing wrong with the AD595 other than price per channel. In fact I may build up one as a reference.

For the rest of the Arduino modules, again, we may try a bunch of different ones - in fact, we don't have to all choose the same one - we have lots of configurations to choose from, so we'll pick the one that best suits the specific roaster or temp measuring situation. But at the moment, I'm working with a couple different modules from Modern Devices, and I'm really like the small modules from Jeelabs, though I don't know if I'll use their radios.

All of the modules I'm testing are 'Open Source Hardware' and have 'Open Source' software also. This means we could, if and when it makes sense, cut & paste their Eagle schematics and pcb files and spin our own boards at 4PCB.com for example. More later, gotta run.
Edited by bvwelch on 05/16/2010 4:36 PM
 
Randy G
So I was thinking that when my two permanent mounted thermocouples arrive that I could use my datalogging, dual channel meter, get the USB update software and cable, and be able to better monitor my roasts until this project is done... so I hooked my meter using the serial cable to my desktop to play with it,... and it isn't working. I don't know how to test whether it is the meter or the cable- I know the port is operational.. Calling Omega tomorrow.

Life's too short to drink bad coffee.
 
randytsuch

Quote

Randy G wrote:
So I was thinking that when my two permanent mounted thermocouples arrive that I could use my datalogging, dual channel meter, get the USB update software and cable, and be able to better monitor my roasts until this project is done... so I hooked my meter using the serial cable to my desktop to play with it,... and it isn't working. I don't know how to test whether it is the meter or the cable- I know the port is operational.. Calling Omega tomorrow.


If you have an ohm meter, you can check the cable
Here is the pinout
http://en.wikiped...32#Pinouts
Look at the DE-9 column, but you only need pins 2, 3 and 5.
2 and 3 may be reversed (pin 2 goes to pin 3 on the other side, and vice versa).

Randy
 
randytsuch

Quote

bvwelch wrote:
Hi Randy, it is hard to say - could be the flakey TC I was using - bought some cheap 'extension wire' thinking I could make my own TCs. It wasn't designed for this, in fact it began to melt during the roast - ugh.

I may go with the AD595, but I am trying a really cheap 18-bit ADC first. If it works, it will save a ton of money over the AD595, especially if you wanted 4 channels. There are several different cheap ADC chips that could work, but I'm going with I2C parts as much as possible. The first chip I am testing is the MCP3424. It may take a few iterations before we find the best (cheapest) solution. But nothing wrong with the AD595 other than price per channel. In fact I may build up one as a reference.


Hi Bill
I think using an A/D, and designing the circuit is a great idea. I was justing thinking about building one for me, but as a community project, it makes sense to design a little, cheaper circuit, and maybe getting some boards built.

I probably have a spare TC around, if you want to borrow one.

Are you sure you aren't getting some error at higher temps? You could test with a heat controlled soldering iron, it should be a fairly stable temp. Try comparing a temp meter to your rise o meter with the iron as the heat source.

Randy
 
bvwelch
Hi Randy. Thanks for the idea of the soldering iron. I'll give that a try. I can also rig up a test with my heatgun on its lower setting.

I've ordered some new TCs and they should arrive in a day or two. Meanwhile I can probably steal one from one of my other roasters.

About building PCBs - I like 4PCB.com pretty well. For about $100, you can get about 10 small boards built, using their 'barebones' pricing.
Edited by bvwelch on 05/17/2010 10:34 AM
 
Randy G

Quote

randytsuch wrote:
If you have an ohm meter, you can check the cable
Here is the pinout
http://en.wikiped...32#Pinouts
Look at the DE-9 column, but you only need pins 2, 3 and 5.
2 and 3 may be reversed (pin 2 goes to pin 3 on the other side, and vice versa).

Randy

The problem is that this is an IR to RS-232 cable, so thee is no way to throw a meter on the tying for testing. I called technical support and they had no way for me to test it other than to buy another cable and hope it wasn't the meter. I can bet as to whether the cable itself is bad for $30 +S/H or replace the meter for about $135 with trade in of my old meter... :(

I suppose I could get the cable and if it didn't work sell the new cable....

Life's too short to drink bad coffee.
 
endlesscycles
Does anyone know what is the datalogger coffeesnobs is selling and has based their software off?

http://beanbay.co...ata-logger
-Marshall Hance
Asheville, NC
 
randytsuch

Quote

endlesscycles wrote:
Does anyone know what is the datalogger coffeesnobs is selling and has based their software off?

http://beanbay.co...ata-logger


I have one at home ;).
I was not able to find one for sale in the states, so I ordered one from CS.

Randy
 
endlesscycles

Quote

randytsuch wrote:

I have one at home ;).
I was not able to find one for sale in the states, so I ordered one from CS.

Randy


Brand? Model#?
-Marshall Hance
Asheville, NC
 
endlesscycles

Quote

randytsuch wrote:
...
I was also looking a little at this guy
http://www.coffee...ast/482368
It was some thinks already set up, but I was worried it might be limited, and I'm not sure how easy it would be to expand it.

Randy


Holy cow, that thing is awesome!
-Marshall Hance
Asheville, NC
 
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