Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
You must login to post a message.

08/16/2019 3:04 PM
I did not get the usual email notice of a PM in my inbox.

08/07/2019 3:29 PM

08/07/2019 3:28 PM
Thank you for all you do. :)

08/07/2019 1:13 PM
Donation added rockon

08/06/2019 8:49 AM
Coffeecooker seems to have joined long enough to post in the chat area. --Stayed a whole 7 minutes--

Users Online
Guests Online: 8

Members Online: 0

Total Members: 6,088
Newest Member: BrewBoy
In Memory Of Ginny

Latest Donations
allenb - 25.00
snwcmpr - 10.00
Groveland Hill Roas... - 25.00
renatoa - 2.00
JitterzZ - 50.00

View Thread

Who is here? 1 guest(s)
 Print Thread
TC4+ Arduino coffee roaster shield (TC4-compatible)
chmod755 wrote:


I hope someone sees this and can give me some guidance.

I just received my TC4+ board and I'm not sure how to make the connections.

I'm building an air blown, gas powered roaster. The air blower powered by an AC universal motor and is driven by a PWM AC dimmer circuit: https://www.tindi...50hz-60hz/

The dimmer circuit accepts 3.3V or 5V PWM signals up to 10kHz.

The propane gas is controlled by a Clippard EVP proportional valve and driven by Clippard's EVPD driver board:
The driver board accepts signals as follows: 0 to 5 VDC, 0 to 10 VDC, 0 to 20 mA, 4 to 20 mA, PWM @ ?2 kHz duty cycle

The TC4+ is able to control the dimmer circuit and the EVPD board on IO3 with IO3,x/n serial commands but I don't seem to be able to use IO2, OT1, or OT2.

I'm using the aArtisanQ_PID sketch and i've configured it to use CONFIG_PWM.

I've also tried installing a version of aArtisan_PID that enables high speed PWM on OT1 but it doesn't seem to work.

Any ideas on how I can use the TC4+ to control both the blower and the gas valve?

Hi chmod755! Good question. IO2 is meant for external interrupts, but you can do PWM on a number of other pins, for instance IO6. You should be able to use the command "AWRITE,D06,xxx" - could you give that a try and report back? It should work fine, it's just that aArtisan / aArtisanQ_PID don't have an extra command specifically for it. To connect to IO6, you can use 5V and GND from IO2 or from the power pins on the Arduino pin header, and IO6/D6 as the PWM pin (that's on the Arduino header near where the IO2/3 headers are).

What's that version with high-speed PWM on OT1? I hadn't come across that before, but happy to have a look at what might be going on there.
Edited by mg512 on 08/08/2019 10:23 PM
Using AWRITE you should also pay attention to the frequency of generated PWM, if it is appropriate for the equipment being controlled.


PWM speed on OT1 can be changed using TIME_BASE in user.h, and indeed it seems there is someone who reserved a placeholder for a future intended high speed versions:

// The faster frequencies below are for advanced users only, and will require changes to the PWM16 Library
//#define TIME_BASE 15 // approx. 977 Hz
//#define TIME_BASE 7 // approx. 1.95kHz
//#define TIME_BASE 6 // approx. 2.2kHz
//#define TIME_BASE 3 // approx. 3.9kHz

No idea if such PWM16 custom library was ever been released...
Edited by renatoa on 08/08/2019 10:47 PM
renatoa wrote:

Using AWRITE you should also pay attention to the frequency of generated PWM, if it is appropriate for the equipment being controlled.

Oh, that's a good point, thank you for catching that. chmod755, you should probably be fine if you put the valve on IO3, and the PWM dimmer board on one of the standard PWM pins (e.g. IO6) with the AWRITE command.
Jump to Forum:

Similar Threads

Thread Forum Replies Last Post
CoffeeAir II Roaster Build Fluidbed Roaster 281 08/13/2019 6:29 AM
KKTO - My Humble Turbo Roaster Turbo Oven Roasters 172 08/09/2019 12:00 AM
Another 1.5kg or 3lb drum roaster from scratch Building a Coffee Roaster 99 08/07/2019 5:48 AM
My drum/bbq roaster Drum Roasters 4 08/06/2019 10:34 AM
Need your help designing a roaster - ESP32 Dataloggers/Controllers/Rate of Rise Meters 3 07/31/2019 8:07 PM
Homeroasters Association Logo, and all Content, Images, and Icons © 2005-2016 Homeroasters Association - Logos are the property of their respective owners.
Powered by PHP-Fusion Copyright © 2019 PHP-Fusion Inc
Released as free software without warranties under GNU Affero GPL v3
Designed with by NetriX