roaster control widget

[milowebailey]

I got the beta hardware interface board put together yesterday and updated the PC code to plot bean temperature and profile temperature together.... (big progress).  I picked up the Alpenrost this morning (I'd sold it to a friend 2 years ago and he's never used it so I bought it back) and will probably start tinkering with it today or tomorrow... I can't wait until the weekend.  I think it's the little kid in me.

Photos and screenshots to come in the next couple days.

Also I've decided to design a generic hardware interface board that would work with any roaster.  I may move over from solid state relays to SCR's so I can get more current switching for the $$ (make the board a little less expensive).

The idea is the the generic board will have:

• Up to 4 AC on/off circuits (up to ?? amps each).
• Accept up to 3 thermocouples so as to measure 3 temperatures.
• Up to 2 dc on/off/forward/backward circuits
• 1 dc variable voltage circuits to control the speed of a motor
• maybe 1 variable AC speed control output

 

I think this would accommodate most any roaster.  Any thoughts?  Anything I've left out

[MMW]

The idea is the the generic board will have:

• Up to 4 AC on/off circuits (up to ?? amps each).
• Accept up to 3 thermocouples so as to measure 3 temperatures.
• Up to 2 dc on/off/forward/backward circuits
• 1 dc variable voltage circuits to control the speed of a motor
• maybe 1 variable AC speed control output

 

I think this would accommodate most any roaster.  Any thoughts?  Anything I've left out

Will the PID code be resident on the Arduino, or will the horsepower come from the PC with the widget acting as a acquisition/control interface?  I haven't fooled with the arduino in any detail yet, but I'd wager that this is going to push the limit on clock cycles and/or code space and/or memory pretty quickly.

[milowebailey]

The idea is the the generic board will have:

• Up to 4 AC on/off circuits (up to ?? amps each).
• Accept up to 3 thermocouples so as to measure 3 temperatures.
• Up to 2 dc on/off/forward/backward circuits
• 1 dc variable voltage circuits to control the speed of a motor
• maybe 1 variable AC speed control output

 

I think this would accommodate most any roaster.  Any thoughts?  Anything I've left out

Will the PID code be resident on the Arduino, or will the horsepower come from the PC with the widget acting as a acquisition/control interface?  I haven't fooled with the arduino in any detail yet, but I'd wager that this is going to push the limit on clock cycles and/or code space and/or memory pretty quickly.

The PID will reside on the Arduino.  It has been used on an espresso machine already... not by me, but by someone else. I'm thinking that the heat control update will only need to be done every 1 - 3 seconds.  So lots of processor time for the PID... that said I have not tried the PID yet.  I'm hoping to give that a try this weekend. 

[Monito]

...snip...
BTW I'm using som solid state relays ($4 ea) for the blower and  the heater.
snip......

Where did you buy those...that is inexpensive. I pay $10 for 25Amps

-pat

[milowebailey]

...snip...
BTW I'm using som solid state relays ($4 ea) for the blower and  the heater.
snip......

Where did you buy those...that is inexpensive. I pay $10 for 25Amps

-pat

Pat

these are only 2 amp... purchased through Digikey... what are you controlling that pulls 25 amps?

[Monito]

...snip...
BTW I'm using som solid state relays ($4 ea) for the blower and  the heater.
snip......

Where did you buy those...that is inexpensive. I pay $10 for 25Amps

-pat

Pat

these are only 2 amp... purchased through Digikey... what are you controlling that pulls 25 amps?

The Heating elements from my 1.5 K roaster (2k Watts)...

-pat

[milowebailey]

I think an SCR might be a better device to switch that on/off... I'll look into it.

[milowebailey]

...snip...
BTW I'm using som solid state relays ($4 ea) for the blower and  the heater.
snip......

Where did you buy those...that is inexpensive. I pay $10 for 25Amps

-pat

Pat

these are only 2 amp... purchased through Digikey... what are you controlling that pulls 25 amps?

The Heating elements from my 1.5 K roaster (2k Watts)...

-pat

This little guy would do nicely.  25 amps @ 800 volts.

$1.35 through digikey.  I does require a Triac driver(optical isolator $1.25) and big heat sink, but that might add another $1 - 2...

I don't need that much current capability, but I'll design for 25 amps.... and fuse it at 20 amps as your application only needs 18 amps

[barko78]

I got the beta hardware interface board put together yesterday and updated the PC code to plot bean temperature and profile temperature together.... (big progress).  I picked up the Alpenrost this morning (I'd sold it to a friend 2 years ago and he's never used it so I bought it back) and will probably start tinkering with it today or tomorrow... I can't wait until the weekend.  I think it's the little kid in me.

Photos and screenshots to come in the next couple days.

Also I've decided to design a generic hardware interface board that would work with any roaster.  I may move over from solid state relays to SCR's so I can get more current switching for the $$ (make the board a little less expensive).

The idea is the the generic board will have:

• Up to 4 AC on/off circuits (up to ?? amps each).
• Accept up to 3 thermocouples so as to measure 3 temperatures.
• Up to 2 dc on/off/forward/backward circuits
• 1 dc variable voltage circuits to control the speed of a motor
• maybe 1 variable AC speed control output

 

I think this would accommodate most any roaster.  Any thoughts?  Anything I've left out

Maybe a second vairable voltage output for burner control.  The burners on my ambex are controlled by a knob that sends a variable dc signal to a digital proportioning valve.  A variable dc output in addition to the motor output would be huge in my book. 
Is the 1st variable dc output to control a motor that would open a dump door possibly??

[Monito]

Is it sending a variable Voltage or Variable signal on DC?

Signal would be better...

-pat

[milowebailey]

Is it sending a variable Voltage or Variable signal on DC?

Signal would be better...

-pat

when you say variable signal on dc.... that to me means an AC signal with a DC offset.... I'm guessing the Ambex burner is controlled is using a voltage from 0 - 24 volts in x number of steps... e.g. 12 volts would have the valve open 50%.  variable DC voltage.. fairly easy to do.... but more circuitry if it's more than 5 volts.... the interface board is getting larger 

I may have to re-think this a bit an maybe have a large and small interface board.   Small for simple roasters SC/TO Sonofresco.  Large for Probat, Ambex etc.....  Where the small board would be a subset of the larger board.....

[mp]

I may have to re-think this a bit an maybe have a large and small interface board.   Small for simple roasters SC/TO Sonofresco.  Large for Probat, Ambex etc.....  Where the small board would be a subset of the larger board.....

Milo ... I see your widget is transforming into an all purpose modularized coffee roaster pid'd programmable one stop solution.

 

[milowebailey]

I may have to re-think this a bit an maybe have a large and small interface board.   Small for simple roasters SC/TO Sonofresco.  Large for Probat, Ambex etc.....  Where the small board would be a subset of the larger board.....

Milo ... I see your widget is transforming into an all purpose modularized coffee roaster pid'd programmable one stop solution.

 

Yep, the Milowidget is Frankensteinish!

[J.Jirehs Roaster]

I may have to re-think this a bit an maybe have a large and small interface board.   Small for simple roasters SC/TO Sonofresco.  Large for Probat, Ambex etc.....  Where the small board would be a subset of the larger board.....

Milo ... I see your widget is transforming into an all purpose modularized coffee roaster pid'd programmable one stop solution.

 

Yep, the Milowidget is Frankensteinish!

FrankenWidget.....

Ok... so I been looking at these Arduino thangs.... will the Nano or BoArduino work with no modification of your software??  I am cheap, yes but it alo plugs directly to the bread board..    I think its a bad idea because I am tied to the PC for USB power but curious

~~edit:  I see as I read trough again the link to sourceforge has equipment list... ~~~
~~edit2: but I cant seem to find it   do I have to be one of the developers?? ~~~

also what do I need to start looking for ...

bread board                     (radio shack)
thermal probe part #'s ??   (digikey)
misculaniouse LEDs,
diodes,
transistors???                   (radio shack)

I don't think I can spend much now but I saw a few things on sale at radio shack and started wondering what deals I should be jumping on

[milowebailey]

J. J.

It looks like either of those other boards would work.  You will have to select the board you have before you run the compiler.  You might want to hold off buying components until you know what you need.  Save up for the bigger items.

Thermocouple,  Thermocouple driver, solid state relays or Triacs depending on which one you'll need.

Here is what I bought to start:

Arduino
USB cable (my Arduino came with one)
Breadboard (digikey 438-1046-ND)
Thermocouple (digikey TP-29-ND)
Thermocouple driver ( digikey AD595CQ-ND)
I'd buy the above at either digikey or Frys electronics... stay away from Radio shack for this stuff  IMO

a selection of LED's (I had a bunch) Radio shack may have a selection.
a selection of 1/4 watt resistors (10k, 1k, 330 Ohms)  Radio shack may have a selection.