HT Roaster Interface

HTShield with TC4 and Arduino
Stacked configuration: HTShield + TC4 Shield + Arduino Uno

Update 04-May-2017: MLG Properties is on SUMMER BREAK! Boards will again be available in August.

Update 10-April-14: To address fan issues that can cause the roast to freeze, users of the RoastLogger program with Hottop roasters should download and install the latest versions of both the RoastLogger program, and the companion RoastLoggerTC4 sketch.

Update 07-April-14: Please read this important notice about possible Hottop roaster freezes during roasts.

Update 11-Feb-14: HTRI devices are once again available to order. Issues with Hottop P-2K model are resolved!

Update 10-Sept-2012: Users Guide now available!

HT Roaster Interface devices enable you to control the heater and fan on your roaster. They provide a link between the roaster's internal electronics and the outside world in a 3-part system:

HT Roaster Interface devices are experimental devices and intended to be used only by those skilled in electronics. Please read this disclaimer carefully before deciding whether or not modifying your roaster with this experimental device is a good idea for your situation.

HT Roaster Interface devices are available in two forms:

  1. HTShield: Arduino-compatible shield, intended for stacking atop a TC4 shield
  2. HTC: may be piggybacked on a TC4C board, or may be used as a remote, cable-connected interface

While HT Roaster Interface devices work particularly well with Hottop roasters, they are neither endorsed by Hottop nor in any way affiliated with Hottop.

HT Roaster Interface devices require an additional Hottop cable for making the necessary connections inside a Hottop roaster. A limited number of those cables are now available here. You will need to purchase one of these cables, either 7-wire or 8-wire, depending on your roaster model.

These cables may also be purchased from Hottop USA:
7-wire Hottop internal cable (Model KN-8828D roasters)
8-wire Hottop internal cable (Models KN-8828B and KN-8828P roasters)

A comprehensive user guide, written by Randy Glass, is now available: HTRI-UserGuide-v100

In addtion, Barrie has posted on an excellent guide for interfacing the HTRI system to the Artisan program:

If you would like to order one or more items, please use the PayPal links below.

Orders shipped to US addresses will be mailed using USPS Priority Mail (small flat rate boxes).

Orders shipped to non-US addresses will be mailed using either USPS Priority Mail International (small flat rate boxes) or USPS Express Mail International (legal size flat rate envelopes). Please click here for important information to help you understand these options and to understand the limits of our responsibility for your package once it has been mailed.

Despite my best efforts with setting things up through PayPal, sometimes customers are charged too much for shipping when more than one item is purchased. If this happens, I will refund the excess shortly after your order is received. But if you think you have been charged too much for shipping and I have not made a refund, please send me a note.

MLG Properties, LLC
Lexington, KY

HTC options
Available Aug. 1
Includes both HTC Roaster Interface Device and TC4C temperature controller board. Includes red "heater ON" LED for panel mounting and nylon spacers to connect HTC and TC4C. Shipped in stacked configuration, ready for installation (you will need to supply hardware for mounting inside your roaster). TC4C pre-programmed with RoastLoggerTC4.
HTShield options
No longer available.
This is the Arduino-compatible shield version of the HT Roaster Interface. Select this option if you prefer to use an Arduino Uno* along with a TC4 shield. Note that the Arduino Uno is not included and must be purchased separately. Includes red LED with lead wires and connector for a panel-mounted "heater-ON" indicator.
No longer available.
Includes HTSHIELD, plus a TC4 shield. Also includes red LED with lead wires and connector for a panel-mounted "heater-ON" indicator. Note that an Arduino Uno* board is also required, but is not included. The Uno must be purchased separately.
Hottop Internal Cables
Available Aug. 1
Internal Hottop 8-wire cable is available here as a convenience. May be purchased from Hottop at lower cost. Order this cable if you have any Hottop B or P model roaster.
No longer available.
Internal Hottop 7-wire cable is needed if you have a Hottop D model roaster. We no longer stock them, but can be purchased from Hottop USA.

*A word about Arduino boards: the TC4 shield is known to be 100% compatible with Arduino Uno and Duemilanove boards. Arduino Diecimila is believed to be compatible, but hasn't been tested by MLG. The Arduino Mega and Leonardo boards are not compatible with the TC4 shield because of differences in the locations of the I2C pins on the stacking headers. Compatibility with other variants of the Arduino boards is unknown, but in general if the stacking header layout of the board in question is consistent with Uno/Duemilanove, the board should be compatible with TC4.

Above: HTC and TC4C in piggyback configuration (note: design improvements have eliminated the need for an external cable).

Above: HTShield board layout

Above: HTC board layout