Auto Roasting (Curve Replay)

Auto Roasting uses a selected roast profile as a “replay script”. During a live roast, the app sends control/temperature commands to reproduce that roast’s pacing as closely as possible. You still watch the roast for safety, and you still need to drop on the roaster yourself.

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1. When does it take over?

Auto Roasting does not take over immediately when you tap “Start Roasting”.

It starts after Charge.

• With auto charge detection enabled: the app detects Charge, resets timer to 00:00, and starts replay.
• Without it: you must manually tag Charge after charging beans.

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2. Two modes: Control Replay vs Bean Temp Tracking (PID)

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2.1 Control Replay (action replay)

This mode replays the recorded control actions in the selected profile at the same timestamps, such as:

• heater power
• fan/damper
• drum speed
• (optional) wind pressure balance target (if recorded & supported)

That also means you should select a profile that actually contains those control records. If a profile only has temperature curves (no control data), there may be little or no automatic adjustments, and you may hear a “no more scheduled control changes” reminder.

New in v1.4.0: Control Replay Trigger (By Time / Time + Temperature).
Choose it in Auto Roasting settings. See Control Replay Trigger.

Quick example: Time + Temperature

Reference: at t=2:00, BT=170C, heater 80 -> 60 (decrease)

Timeline: 1:50 -----2:00-----2:10-----2:20
BT:                        hits 170°C

By Time:         [decrease]
Time+Temp:                   [decrease]

• If your roast is faster, Time + Temp decreases earlier to avoid overshoot
• If your roast is slower, Time + Temp decreases later to avoid dragging it down

2.2 Bean Temperature Tracking (PID)

This mode continuously sends a target bean temperature to the roaster’s PID controller to follow the reference curve, and may also replay fan/drum actions.

On some drum roasters, PID tracking may overshoot or follow poorly due to stronger thermal inertia; if that happens, prefer Control Replay or manual roasting.

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3. What you may see/hear during replay

• Controls may be locked to avoid conflicts; end Auto Roasting first if you want to take over.
• TTS (optional): announces control changes, event tags, and reminders.
• Auto tagging (optional): can auto-tag Dry End / First Crack / Second Crack using reference thresholds.
• Smart reminders (optional): approaching First Crack (30s) and approaching Drop Temp (within 5°C), if those events exist in the reference.

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4. When does it end? How to take over?

You can end Auto Roasting at any time to take over. After that, the app stops sending further auto commands and you continue manually.

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Natural ending differs by mode:

4.1 Control Replay: ends when the reference curve ends

When roast time reaches the end of the reference curve, the app announces “Auto Roasting Finished” and stops sending further auto control commands (no rollback / no restore).

4.2 Bean Temp Tracking: ends the roast when the reference ends

When roast time reaches the end of the reference curve, the app announces “Auto Roasting Finished” and ends the roast session (e.g., stop recording and disable PID auto-heating).

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5. Other notes / common pitfalls

1. You still need to drop manually: be ready near the end.
2. “No more scheduled control changes” (Control Replay):
   • if the later part of the reference is flat (no changes), after the last change point there will be no more auto adjustments;
   • the replay still continues until the reference curve ends;
   • take this as a signal to watch roast progress and drop timing more carefully.
3. Keep beans & batch size close to the profile: large differences can cause significant deviation even if replay is correct.
4. Intervene decisively: if you must adjust controls, end Auto Roasting first to avoid command conflicts.