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SUNLU AMS Heater Auto-Vent Controller - User Guide

Table of Contents

  1. Introduction
  2. Quick Start
  3. LED Status Indicators
  4. Button Controls
  5. Learning Mode
  6. Normal Operation
  7. Troubleshooting
  8. Maintenance
  9. Safety Information

1. Introduction

The SUNLU AMS Heater Auto-Vent Controller is an intelligent automation system for your 3D printer filament dryer. It automatically opens and closes a vent based on the dryer's operating state, helping to:

  • Remove excess moisture during drying cycles
  • Manage temperature buildup
  • Prevent moisture build-up inside the unit due to heating with the vent closed
  • Extend the life of your dryer's heating element
  • Reduce energy consumption

The system works by monitoring the electrical current drawn by your dryer and learning to recognize when the heater and fan are operating.

What You'll Need to Build This Project

Purchased from 3dcreator.shop:

  • Custom PCB (bare board or kit with components)

You Will Need to Provide:

  • 3D printed parts (STL files available in repository)
  • Seeed XIAO SAMD21 microcontroller
  • ADS1115 ADC module
  • ACS758 LCB-050B current sensor
  • Feedback-enabled servo motor
  • Momentary push button
  • LED and resistor
  • USB-C cable for power
  • 5V USB power source (1A minimum)
  • Wire for connections
  • Basic soldering equipment
  • Your SUNLU AMS dryer (or compatible unit)

Assembly Time:

  • PCB assembly (if not pre-assembled): 1-2 hours
  • 3D printing parts: 4 hours print time
  • Final assembly and installation: 30-60 minutes
  • Initial calibration: 5 minutes

2. Quick Start

First-Time Setup

Prerequisites:

  • PCB assembled with all components soldered
  • 3D printed parts installed on your dryer
  • Firmware uploaded to XIAO SAMD21 microcontroller

Installation Steps:

  1. Install the Controller
    • Mount the assembled AutoVent onto the top of the sunlu case and plug the cable into the dryer
    • Connect the AC power to the AutoVent
    • Connect USB-C power to the controller

Important: If you need assembly instructions for the PCB or 3D printed parts, refer to the build guide included with your PCB kit or visit 3dcreator.shop for detailed assembly tutorials.

  1. Power On

    • The LED will flash slowly while the system calibrates
    • After 10 seconds, the LED will turn solid
    • The system is now ready

  2. Run Learning Mode (May be required if vent does not immediately open and close as expected)

    • Make sure your dryer is OFF
    • Press and hold the button for 6-7 seconds
    • Follow the LED patterns (see Section 5)
    • Learning takes about 45 seconds total
    • Your settings are automatically saved

  3. Test Operation

    • Turn on your dryer
    • The vent should open when the heater activates
    • Turn off the heater (fan continues)
    • The vent should stay open
    • Turn off the fan
    • The vent should close after 3 minutes

That's it! Your Auto-Vent Controller is now ready for normal use.

3. LED Status Indicators

The status LED tells you what the controller is doing:

Normal Operation

| LED Pattern | Meaning | What's Happening | |-------------|---------|------------------| | SOLID ON | Active | System is operating normally, monitoring your dryer | | OFF | Standby | System is disabled (press button 2-5s to wake) |

Learning Mode

| LED Pattern | Meaning | What to Do | |-------------|---------|-----------| | SOLID ON | Ready and Waiting | Make dryer change, then press button when ready | | FAST FLASH | Measuring | Don't touch! Measurement in progress (10 seconds) | | 3 LONG BLINKS | Learning Complete | All done! Settings saved, back to normal |

Calibration

| LED Pattern | Meaning | |-------------|---------| | SLOW FLASH | Calibrating servo position |

4. Button Controls

The single button provides three different functions based on how long you press it:

Short Press (< 2 seconds)

Function: Recalibrate Servo

When to Use:

  • If the vent isn't opening or closing fully
  • After physically adjusting the servo arm
  • If the vent seems stuck or misaligned

What Happens:

  • LED flashes slowly
  • Servo moves to test positions
  • Takes about 3 seconds
  • Returns to normal operation

Long Press (2-5 seconds)

Function: Enter/Exit Standby Mode

When to Use:

  • When you want to temporarily disable the controller
  • To manually control the vent position
  • During maintenance or cleaning

What Happens:

  • LED turns OFF (entering standby)
  • LED turns back ON (exiting standby)
  • Vent remains in current position while in standby

Note: The LED will turn off after 2 seconds. This is normal - keep holding until 5 seconds to avoid accidentally entering learning mode.

Very Long Press (> 5 seconds)

Function: Enter Learning Mode

When to Use:

  • First-time setup
  • Moving to a different dryer
  • If vent control becomes unreliable
  • After changing the current sensor installation

What Happens:

  • LED turns off at 2 seconds (keep holding!)
  • LED turns back on at 5 seconds
  • Learning mode begins (see Section 5)

Tip: Count slowly to 7 to be sure you've held long enough.

5. Learning Mode

Learning Mode teaches the controller to recognize your specific dryer's electrical signature. This should be done once per dryer.

When to Run Learning Mode

  • Required: First-time installation
  • Recommended: After moving to a different dryer
  • Optional: If you notice the vent not responding correctly

How to Run Learning Mode

Preparation

  • Ensure your dryer is completely OFF (heater and fan)
  • Clear any obstructions from the vent
  • Have your dryer controls within reach
  • Budget 2 minutes of your time

Step-by-Step Instructions

PHASE 1: Baseline Measurement

  1. Start Learning Mode

    • Press and hold button for 6-7 seconds
    • LED turns off at 2 seconds → Keep holding!
    • LED turns back on at 5 seconds → Release button
    • Learning mode begins

  2. LED: SOLID → Waiting for you

    • Ensure dryer is completely OFF (heater and fan)
    • When ready, press button once

  3. LED: FAST FLASH → Measuring baseline

    • System is measuring (10 seconds)
    • Do not touch anything
    • LED will automatically go solid when done

PHASE 2: Heater + Fan Measurement

  1. LED: SOLID → Waiting for you

    • Turn your dryer ON (heater + fan both running)
    • When dryer is running, press button once

  2. LED: FAST FLASH → Measuring heater + fan

    • System is measuring (10 seconds)
    • Leave dryer running, don't touch
    • LED will automatically go solid when done

PHASE 3: Fan-Only Measurement

  1. LED: SOLID → Waiting for you

    • Turn heater OFF (keep fan running)
    • On most dryers: press heat button twice quickly
    • When fan is running alone, press button once

  2. LED: FAST FLASH → Measuring fan only

    • System is measuring (10 seconds)
    • Leave fan running, don't touch
    • Wait for completion

COMPLETE!

  1. LED: 3 LONG BLINKS → All done!
    • Settings automatically saved to memory
    • System returns to normal operation
    • You can now use your dryer normally

Learning Mode Tips

Do's:

  • ✅ Follow the LED patterns carefully
  • ✅ Let measurements complete (don't interrupt)
  • ✅ Make sure your dryer controls work properly
  • ✅ Perform learning when dryer is at room temperature

Don'ts:

  • ❌ Don't rush between phases
  • ❌ Don't touch the dryer during FAST FLASH measurements
  • ❌ Don't turn off power during learning
  • ❌ Don't worry if the vent doesn't move during learning (this is normal)

If Learning Fails

If learning mode doesn't complete properly:

  1. Turn everything off and wait 10 seconds
  2. Start over from Phase 1
  3. Pay close attention to the LED patterns
  4. Ensure your dryer switches modes correctly

6. Normal Operation

Once learning is complete, the controller works automatically. Here's what to expect:

Automatic Vent Control

When Dryer Starts:

  • Heater turns on → Vent opens immediately
  • Fan starts → Vent opens immediately

During Drying Cycle:

  • Vent stays open as long as heater or fan is running
  • No manual intervention needed

When Heater Turns Off (fan continues):

  • Vent stays open
  • This is normal - fan cools down the heater

When Everything Turns Off:

  • Vent stays open for 3 more minutes (cooldown delay)
  • Then vent automatically closes
  • This protects your fan bearing from thermal shock

What You Should See

Normal Behavior:

  • LED is solid ON during operation
  • Vent opens when you start the dryer
  • Vent stays open while dryer runs
  • Vent closes a few minutes after dryer stops

Expected Delays:

  • Vent may take 1-2 seconds to fully open/close
  • 3-minute cooldown delay before closing is intentional

Manual Control (if needed)

While the system is designed for fully automatic operation, you can:

  • Disable temporarily: Press button for 2-5 seconds (standby mode)
  • Recalibrate: Short press if vent isn't moving correctly
  • Relearn: Very long press (5+ seconds) if behavior changes

7. Troubleshooting

Problem: Vent doesn't open when dryer starts

Possible Causes & Solutions:

  1. System in standby mode

    • Check: LED is off
    • Solution: Press button for 2-5 seconds to wake

  2. Learning not performed

    • Check: First time use or new dryer
    • Solution: Run learning mode (Section 5)

  3. Servo not moving

    • Check: Listen for servo motor sound
    • Solution: Try short press to recalibrate
    • If still stuck: Check servo power connection

  4. Current sensor not reading

    • Check: Verify sensor is clipped around ONE power wire
    • Solution: Reconnect sensor, restart controller

Problem: Vent doesn't close after dryer stops

Possible Causes & Solutions:

  1. Cooldown delay active

    • This is normal! Wait the full 3 minutes
    • Small parasitic loads can keep vent open

  2. Dryer still drawing current

    • Check: Does the dryer have a display or light still on?
    • Solution: This is normal if dryer has standby power draw

  3. Thresholds too sensitive

    • Solution: Run learning mode again

Problem: Vent opens and closes repeatedly

Possible Causes & Solutions:

  1. Threshold too close to actual current

    • Solution: Run learning mode again
    • Make sure dryer is at stable temperature during learning

  2. Heater cycling on/off

    • This may be normal dryer behavior
    • Solution: Wait for system to stabilize (30-60 seconds)

  3. Loose sensor connection

    • Check: Ensure current sensor is firmly clamped
    • Solution: Reposition sensor, secure with zip tie

Problem: LED flashing patterns don't match guide

Possible Causes & Solutions:

  1. Interrupted learning mode

    • Solution: Press button 2-5 seconds to exit, try again

  2. Low power supply

    • Check: Using adequate 5V 1A+ power supply
    • Solution: Try different USB power adapter

  3. Firmware issue

    • Contact support for firmware update

Problem: Button doesn't respond

Possible Causes & Solutions:

  1. Button stuck or damaged

    • Check: Press firmly and listen for click
    • Solution: May need button replacement

  2. Holding wrong duration

    • Very long press requires 6+ seconds
    • Count slowly and deliberately

  3. During learning mode

    • Button doesn't respond during measurements
    • Wait for current phase to complete

8. Maintenance

Regular Maintenance (Monthly)

  1. Visual Inspection

    • Check for loose wires or connections
    • Ensure servo arm hasn't come loose
    • Verify vent mechanism moves freely

  2. Clean Sensors

    • Wipe dust off current sensor
    • Check servo feedback sensor (if accessible)

  3. Test Operation

    • Run a short drying cycle
    • Verify vent opens and closes properly

Deep Maintenance (Every 6 Months)

  1. Recalibrate

    • Run learning mode to refresh thresholds
    • Useful if behavior has changed over time

  2. Clean Vent Mechanism

    • Remove dust and debris from vent
    • Ensure smooth movement
    • Lubricate vent hinges if needed (dry lube only)

  3. Check Connections

    • Verify all wires secure
    • Tighten any loose screws
    • Inspect for signs of wear

When to Rerun Learning Mode

  • Moved controller to a different dryer
  • Significant change in vent behavior
  • After replacing current sensor
  • After major dryer maintenance
  • Every 6-12 months as preventive measure

9. Safety Information

General Safety

⚠️ ELECTRICAL SAFETY

  • This device monitors AC mains voltage (120V or 240V)
  • Ensure current sensor is properly rated for your voltage
  • Never touch exposed current sensor connections while powered
  • Disconnect dryer from power before working on connections

⚠️ FIRE SAFETY

  • Controller does not prevent dryer malfunction
  • Never leave dryer unattended for extended periods
  • Ensure proper ventilation around dryer and controller
  • Keep controller away from heat sources

⚠️ MECHANICAL SAFETY

  • Servo motor can pinch fingers
  • Keep clear of moving vent mechanism
  • Ensure vent can move freely (no obstructions)

Proper Use

✅ Do:

  • Use controller within specified temperature range (0°C to 50°C)
  • Provide adequate ventilation
  • Use specified 5V power supply
  • Follow learning mode instructions carefully
  • Check connections regularly

❌ Don't:

  • Don't expose to moisture or liquids
  • Don't block vent mechanism
  • Don't modify electrical connections without proper knowledge
  • Don't use with dryers exceeding 50A current draw
  • Don't bypass safety features

Limitations

This controller is designed to:

  • ✅ Automatically control vent based on dryer operation
  • ✅ Improve energy efficiency
  • ✅ Extend dryer component life

This controller does NOT:

  • ❌ Replace dryer safety features (thermostats, fuses)
  • ❌ Prevent dryer malfunction
  • ❌ Monitor dryer temperature
  • ❌ Provide fire detection or suppression

Environmental Considerations

  • Operating Temperature: 0°C to 50°C (32°F to 122°F)
  • Storage Temperature: -20°C to 70°C (-4°F to 158°F)
  • Humidity: 10% to 90% non-condensing
  • Altitude: Up to 2000m (6500ft)

In Case of Emergency

If you smell burning, see smoke, or suspect malfunction:

  1. Immediately unplug the dryer from wall power
  2. Disconnect controller power
  3. Do not attempt to use until inspected
  4. Contact qualified technician for inspection

Disposal

When disposing of this device:

  • Follow local e-waste regulations
  • Do not throw in regular trash
  • Remove any batteries (if applicable)
  • Consider recycling electronics at designated facility

Support and Contact

Need Help?

If this guide doesn't solve your problem:

  1. Check the Technical Specification document for advanced details
  2. Review the troubleshooting section again
  3. Visit the 3dcreator.shop support page
  4. Check the GitHub repository for community support and discussions

Firmware and Hardware Updates

Purchase PCBs and Components:

  • Visit 3dcreator.shop for the latest PCB versions
  • Choose between bare PCBs or assembled kits with components

Download Design Files: Check the GitHub repository for:

  • Latest firmware versions
  • 3D printable STL files
  • Schematic and PCB design files
  • Bug fixes and new features
  • Community support and build guides

Repository: github.com/kgregg384/SUNLU_AMS_Heater_AutoVent

Appendix: Quick Reference

Button Press Summary

| Duration | Function | LED Response | |----------|----------|--------------| | < 2 sec | Recalibrate | Slow flash | | 2-5 sec | Standby toggle | OFF → ON or ON → OFF | | > 5 sec | Learning mode | OFF (2s) → ON (5s) → Learning sequence |

LED Pattern Quick Reference

| Pattern | Common Meaning | |---------|----------------| | Solid | Normal operation OR waiting for button press (learning) | | Off | Standby mode | | Slow flash | Calibrating | | Fast flash | Measuring (learning) | | 3 long blinks | Learning complete! |

Learning Mode Quick Steps

  1. Dryer OFF → Hold button 6s → SOLID (press button) → FAST FLASH (10s)
  2. Turn dryer ON → SOLID (press button) → FAST FLASH (10s)
  3. Turn heater OFF (fan only) → SOLID (press button) → FAST FLASH (10s)
  4. 3 LONG BLINKS → Done!

Document Version: 1.0 Last Updated: January 27, 2024 For Hardware Version: 1.0 Firmware Version: 1.0

PCBs and Kits Available: 3dcreator.shop Open Source Repository: github.com/kgregg384/SUNLU_AMS_Heater_AutoVent

© 2024 - Firmware and documentation created with assistance from Claude Code This is an open-source hardware project. PCBs and component kits available from 3dcreator.shop