UI suggestion for "Charge"

With v2.0.6, when the roaster automatically goes into “Charge” mode, the preheat graph, time, etc. disappears, and the “Roaster charged, load your beans” message comes up. It would be nice if the preheat graph and time remained visible and updating, as one may wish to extend the preheat time.

Personally, I’ve started tracking the ambient IR temp in the info pane to gauge when the unit is up to temp, but the info pane is also unavailable as soon as the Bullet goes into charge mode.

Also, shouldn’t the charge message say “Roaster ready, charge your beans”, or am I misunderstanding the meaning of “charge”?

And one last point, when doing a profile playback, could the profile name be displayed somewhere.

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I now see you can dismiss the “Roaster charged, load your beans” message without invoking roasting, but that doesn’t bring back the preheat graph or total preheat time.

Hi Peter

Sorry for the wait.
I am not 100% sure I understand why you would want to change the preheat time after the Bullet is ready to start roasting. The idea about using the Infrared sensor to check the drum temperature- which holds most of the energy. We use a few other sensors to determine when the Bullet is heated up to a stable temperature.
The IR ambient is not very reliable when determining if the Bullet is ready, as it it located outside the roast chamber, so depending on your ambient temp it will change.

In playback, you can see the name of the profile in the top of the screen.


Hi Jonas,

My Bullet seems quite variable about if and when it automatically goes to charge mode, particularly at the 195 preheat temp I typically use, so I like looking at the preheat graph (as well as preheat time and ir ambient) to judge when to charge the beans. It seems at the higher preheat temps, (I am roasting 820gm batches almost exclusively), auto charge doesn’t occur much of the time, even after 40 mins preheat. My room temp varies a bit this time of year: 14-20 C. My comments were aimed at the case when the Bullet does go into charge mode automatically… I hear the “charge” command and return to my coffee room, but the preheat graph is gone, as is the total preheat time, so I have only the current bean/drum temps to go by to decide if I should charge then. If I charge too soon, I find my roast can significantly lag the profile I’m playing back, especially on the first of a multi-roast session. So, my suggestion was to not erase the preheat graph and total preheat time when the “Charge” message comes up. (As I noted above, I now realize I can still check the ir ambient after the charge message.)

Regarding the roast name being visible for playback roasts, when I first select a profile the roast name is indeed there in the window. But once I start preheat, and during roasting, the playback roast name is not present. I’m often roasting 3 or 4 different beans back-to-back, so having the playback profile name showing would help confirm that I charge the right beans for the roast profile being played back. (Was I doing the Brazil, Guat or Tanz Peaberry first? Have a brain like a sieve…)

As a side note, as my beans are stored in the coffee room where temps can get quite low at times (~15 C), I’ve recently experimented with warming the beans slightly before charging (say 20 seconds in the microwave). This seems to help significantly when using a playback profile I recorded when the greens we’re initially warmer - much better reproducibility without having to override the playback settings…


Very interesting discussion. Could you elaborate on how the ‘charge’ comment is chosen by the Bullet? I noticed that the ‘charge’ temperature is not dependent on the drum temp. My starting drum temp is usually 170C. The Bullet asks for charging long after the drum temp has been achieved, but at varying bean temps.

Having just updated to the 2.0.8 beta, I see that “Playback Mode” is now indicated on the side panel, as well as the profile name one is playing back. This is great. Further, the “Charge” message doesn’t erase or stop the plotting of the preheat temps. So all is good now!

The preheating graph now comes up over top of the playback profile plot, which is a bit messy, though I guess it gives you a chance to review the profile during preheat to see if you want to try any tweaks while roasting.

Some other changes in 2.0.8 for the playback display (eg. nonscrolling control settings) are also greatly appreciated!

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We use an algorithm to determine when the R1 is ready, so it is not just the drum temperature. We also look at when the bean temp has stabilized and if the front plate is hot enough.
The new IBT sensor uses a little bit different algorithm.

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Hi Peter

Thanks for the detailed reply - I understand it much more clearly now.
I am looking into what we can about your suggestions. Will get back to you shortly about this.

You are absolutely right about getting a more consistent roast by having the same temperature beans ever time. Even just 1 or 2 degrees here can make a big difference. Other factors like your room temperature, and your input line voltage also plays a part here. Our new power electronics will take care of the line voltage problems, and we are working on some more intelligent control algorithms to deal with the other variables.

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