What is Data Logging?

What is Data Logging?


Probe Definition iPhone
Roastmaster, by default, allows you to create any number of Curves in a roast. Curves can store any type of numeric variable that changes throughout the roast, and are displayed as line graphs the Roastmaster’s roasting graphs. These curves can be either Control curves for storing machine settings, like heat, gas or airflow, or Reading curves–to store the temperature readings you observe throughout the roast.

Without the Data Logging option and appropriate hardware, you will need to manually enter values throughout the roast by selecting the appropriate curve in the graph of the main roasting console (or analyzer), then tapping the digital readout near the roasting gauge, and entering the value. It will then be recorded in the curve, at the appropriate time in the roast.

The Data Logging option removes most of the manual data entry from your roasting workflow for Reading curves (Control curves are not applicable, and cannot be used with the Data Logging option). With the appropriate hardware, the Data Logging option allows you to create logical Probes in Roastmaster that link to physical thermocouples inserted in your roaster. Once these probes are defined, you can link them to your Reading curves in a new roast. Once linked to a Probe, a Reading Curve becomes bound to the physical thermocouple that the Probe controls.

Once a Reading curve is bound to a Probe, the roasting console will report the probe’s exact temperature in real time, and automatically record temperatures at user-definable intervals in the Reading Curve throughout the duration of the roast.

In order to use data logging, you will need the following:

  • A roaster that can be safely modified to accept a thermocouple
  • One of the supported probe hardware configurations (see Getting Started With Data Logging)
  • The Roastmaster Data Logging option

The Data Logging option unlocks all Data Logging features in Roastmaster, and allows you to define probes to use with curves during your roasts.

Once you’ve defined your probes, you need only to create one or more reading curves in a new roast (1 for each probe you want to use). In the curve details screen, choose the probe you want to use for that curve. Once you’ve chosen a probe, Roastmaster will link to that probe and begin reporting temperatures in the Roast Console and Full Screen Graph. When you start the roast, Roastmaster will begin sampling temperatures at definable intervals throughout the roast, creating nodes in the curve automatically as the roast progresses.

If you use probes often, consider using the “Curve Templates” feature available in Profiles and Programs. Curve Templates allow you to create blank, placeholder curves in a Profile or Program. Then, whenever you tag that Profile or Program in a roast, Roastmaster will automatically create new, identical curves in the roast for the purpose of recording new data. If you’ve set the probe binding of the Curve Templates, the newly-spawned curves will automatically link to its bound probe, and begin reporting data. Curve Templates eliminate the need for time-consuming roast configuration, making the setup process a one-tap affair. 

For setup instructions, please see Getting Started With Data Logging.

  1. Benjamin Webb
    Benjamin WebbOct 20, 2013

    I want to set up the data logging exactly like you have in the “ROASTMASTER DATA LOGGING WITH PHIDGET TEMPERATURE SENSOR AND LAPTOP HOST” example. I even have the same Quest M3 roaster. How did you install the thermocouples into the roaster? Did you find some aftermarket pieces that screw into the thermometer ports?

    • Danny Hall
      Danny HallOct 20, 2013

      Hi Benjamin

      In the states, metric parts are hard to come by. I ordered them from a guy named Eric Svendson. Nice guy – he has a parts list here… http://users.rcn.com/erics/Quest_Thermocouples_03.pdf

      I didn’t order the fancier compression fittings (he was out of them at the time). Instead, I just ordered 2 of the M8 screws drilled for 1/8″ probes to fit my thermocouples. If you go this route, I advise you do something to keep the probes from accidentally sliding in too far and hitting the drum tines. I used foil HVAC tap wrapped around the probes at the proper depth – works great for me.

      Good luck! Let me know if you have other questions.


  2. Philip Brink
    Philip BrinkNov 14, 2013

    Hi Danny,

    First up, I’m in Cape Town, South Africa. Hardware is an issue. I use a Toper Cafemino (gas) roaster (http://www.cafemino.com/e-cafemino-gaz.html) and have been using standard roasting sheets to track my roasts. I’m really keen on getting your App, but I want to know if my roaster is suited to also getting the data logging option. My roaster is in a fixed location so just attach to my laptop directly. Anyhow, I’m not really that technically minded so I cannot say whether the Thermocouple on my roaster will hook up to the phidget temperature sensor. I’m not sure there’s enough info on the Toper website but I can send you the pdf document that deals with the thermocouple specifications. My confusion stems from the index suggesting a J-type and K-type compatibility but in the manual itself it only describe the J-type. Are you able to confirm?



    • Danny Hall
      Danny HallNov 14, 2013

      Hi Philip

      Not sure if you’re referring to your Cafemino’s documentation or Roastmaster’s documentation, but Roastmaster will accept either a J or K style thermocouple with Phidgets hardware. Setting the probe type is a simple preference setting in the probe details view in the app.

      In the foreseeable future, the only option for J type thermocouples in Roastmaster will be Phidgets. I’m submitting an update tomorrow that will provide support (if approved by Apple) for another piece of hardware, but that is K style only. The end result in any case, though, is the same – all that needs to happen from Roastmaster’s perspective is that the Phidget hardware be wired to a thermocouple, so that part is very straightforward.

      Mod’ing a roaster, though is more involved. I’m sorry, I can’t say directly what the process would be for roasters with pre-wired thermocouples, only advise that you’d need to make sure it’s safe to reroute the built-in thermocouple. i.e. Verify that its output is for display purposes only, and not somehow integrated into the internal function of the machine, or its gas/heat/timing controls -OR- find a way to safely install a second thermocouple.

      I would be interested in looking at the manual – if you have a PDF version please send it over, or if you have a contact at the company and want to discuss it by phone, I’d be happy to sit in a conference call – it would be a learning process for me to familiarize myself with this particular roaster. Please let me know via email and we can continue this conversation: support@rainfroginc.com

      Kind regards
      Danny Hall

  3. James Reid
    James ReidSep 30, 2014

    Here’s my question, fellow roasters and FrogTree engineers:

    Reading air temp in the roasting chamber gives us the outline of the bean temp curve, but doesn’t follow true bean temp as the air buffers the delta (change) in the bean temp.

    Particularly, when, during first crack, when the roasting goes exothermic, air temp reading is going to lag behind actual bean temp.

    Be really nice to know by about how much, but without being able to read bean temp directly (Behmor Plus) I wonder whether and how we might determine this compensatory factor.

    Also, air temp curve likely outlines the bean temp curve with a time offset as indicated in the previous observation. I wonder whether and how we might determine the temp difference between beans and chamber and, also, whether this difference remains linear or varies otherwise predictably (formula).

    Anybody have any thoughts on this?

    🙂 Cheers.

Leave a Reply