roaster control widget

[milowebailey]

Looks like my test on my Alpenrost will be delayed a few days.  The electric heater needs a 16 amp relay and I only have 2 amp relays so I have to order some parts.... delayed until early next week I suspect..... unless I can find a Triac somewhere in my stash of electronic junk.

[J.Jirehs Roaster]

J. J.


I'd buy the above at either digikey or Frys electronics... stay away from Radio shack for this stuff  IMO

I just wandered in to Radio Shack... I typically go to a local electronics place north of me (Chesters Elec.) for serious stuff like this... its the kind of place they named radio shack after.... amazing they can stay open.. I guess because they are the only one...

[mp]

Looks like my test on my Alpenrost will be delayed a few days.  The electric heater needs a 16 amp relay and I only have 2 amp relays so I have to order some parts.... delayed until early next week I suspect..... unless I can find a Triac somewhere in my stash of electronic junk.

Meanwhile you can brew some coffee and enjoy!

 

[MMW]

Thought about adding data logging?  Using this perhaps?  There is a bit about it on the arduino playground as well.  Looks like it only takes 2 pins for a serial interface.

A jump drive might be an interesting place to store a profile too.

[milowebailey]

Thought about adding data logging?  Using this perhaps?  There is a bit about it on the arduino playground as well.  Looks like it only takes 2 pins for a serial interface.

A jump drive might be an interesting place to store a profile too.

I could easily add datalogging since I'm already reading the USB port with the PC... just a matter of writing that data to a file.  Probably a bit down the road, but I could easily do that.

[J.Jirehs Roaster]

Thought about adding data logging?  Using this perhaps?  There is a bit about it on the arduino playground as well.  Looks like it only takes 2 pins for a serial interface.

A jump drive might be an interesting place to store a profile too.

I could easily add datalogging since I'm already reading the USB port with the PC... just a matter of writing that data to a file.  Probably a bit down the road, but I could easily do that.

I'm sure the data log to jump drive will go well with the LCD display and possibly even allow us to change profiles with out the lap top but I for one see the spare laptop in my junk room as the cheap work around for most of the extras (assuming it still works) 

[milowebailey]

I got the hardware for the Alpenrost interface.  I started gluing last night and I'm hoping to get it all glued together this afternoon... maybe fire up the alp tonight or tomorrow.... photos to come.

[mp]

I got the hardware for the Alpenrost interface.  I started gluing last night and I'm hoping to get it all glued together this afternoon... maybe fire up the alp tonight or tomorrow.... photos to come.

Good news Milo ... now progress continues.

 

[J.Jirehs Roaster]

Thermocouple (digikey TP-29-ND)
Thermocouple driver ( digikey AD595CQ-ND)

thermocouples and driver question.... the thermocouples I already have are K type... I presume they will work.. I know the bead end ones are faster but I have what I have.... some are enclosed in a metal probe and at least one is the little button tipe that screws into the side of the roast chamber but stays close to the wall... Is that a safe presumption? and will the thermocouple driver work with other types of thermocouples like J

[milowebailey]

Thermocouple (digikey TP-29-ND)
Thermocouple driver ( digikey AD595CQ-ND)

thermocouples and driver question.... the thermocouples I already have are K type... I presume they will work.. I know the bead end ones are faster but I have what I have.... some are enclosed in a metal probe and at least one is the little button tipe that screws into the side of the roast chamber but stays close to the wall... Is that a safe presumption? and will the thermocouple driver work with other types of thermocouples like J

Yes,..... they should work with the AD595xx driver... it's for a K type thermocouple.  If you have a J type then use an AD594xx driver.

The thermocouple type depends on the material the wires are made from.  when two dissimilar metals are welded together at one end it creates a voltage based on heat at the other end... very consistent (gas heaters use one to detect the pilot light),  K and J are just different type of wire with different voltage vs temperature curves.  So all K's should work with an AD595 and all J's should work with the AD594.  Keep in mind the polarity matters... if it doesn't work swap the leads.

More here if you want to know.

The AD594/AD595 is a complete instrumentation amplifier and thermocouple cold junction compensator on a monolithic chip. It combines an ice point reference with a precalibrated amplifier to produce a high level (10 mV/?C) output directly from a thermocouple signal.

so using this amp you can use a simple algorithm to convert the mV to degrees... because it's now linear.

[J.Jirehs Roaster]

More here if you want to know.

Thank you...

[mp]

More here if you want to know.

Nice link Milo.

 

[milowebailey]

Here is an update.

I've built 2 prototype interface boards.

The one on the left is a prototype for an all electric roaster (Alpenrost) and has controls for 12 V damper, 12 V drive motor, 110 V AC heater and fan.  It's currently set up for 1 thermocouple, but there is room to squeeze one more driver in the middle of the board.

The one in the center is a prototype for a simple gas roaster (sonofresco) and has controls for 110 V fan, and burner on/off control.  It has 2 thermocouple drivers (although there is no chip in one of the sockets yet).

On the right is the Arduino.

The proto boards are 2" x 3", so you can see how small the Arduino really is.

I'm missing one part for the Alpenrost controler... so It will be at least another day before I get it hooked up and ready to test.

[cfsheridan]

Larry, where are you getting those prototype boards?

[J.Jirehs Roaster]

Larry, where are you getting those prototype boards?

the local prototype board store... of course..