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After flashing the firmware, you can monitor your device’s activity, check battery status, and test functionality using the serial monitor.

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Connect to the serial monitor

Use PlatformIO’s device monitor to view real-time logs from your omiGlass:
The serial monitor connects to your device and displays debug logs, status messages, and allows you to send commands.
Alternative: specify the port If you have multiple devices connected:
To exit the serial monitor, press Ctrl+C

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Available serial commands

Once connected to the serial monitor, you can type these commands to interact with your device:

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Quick status check

Shows current battery level, connection status, and device state. Example output:

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Battery monitoring commands

Charging status

Monitor charging progress in real time

Runtime calculator

See how long your glasses will last

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Charging status monitor

Takes 10 readings over 20 seconds and displays charging status:
  • CHARGING (>4.1V): Actively charging
  • CHARGED (3.9-4.1V): Good charge level
  • LOW (3.7-3.9V): Needs charging
  • CRITICAL (<3.7V): Check connections
Example output:

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Battery runtime calculator

Shows estimated runtime for different usage scenarios based on current charge level. Example output:

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Charge time calculator

Calculates estimated time to reach full charge from current level. Example output:

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Continuous monitor

Enables continuous monitoring with readings every 5 seconds. Type any command to stop. Example output:
Press any key and hit Enter to stop continuous monitoring.

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Battery status reference

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Voltage levels and charging times

Do not let the battery drop below 3.5V as it may damage the Li-ion cells.

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Battery life estimates

Based on dual 250mAh batteries (500mAh total): Current consumption:
  • Active mode: ~80mA (camera + BLE + processing)
  • Standby mode: ~40mA (BLE connected, camera off)
  • Sleep mode: ~2mA (deep sleep, button wake-up)

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Testing your device

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Basic functionality test

1

Connect to the serial monitor

2

Check status

Type status in the serial monitor and verify:
  • Battery percentage is displayed
  • Device reports as ready
  • BLE status shows as active
3

Test battery monitoring

Type charging to verify battery readings are accurate and stable.
4

Connect to the app

Open the Omi app and verify:
  • Device appears in Bluetooth scan
  • Connection is successful
  • Battery level displays in app

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Charging your omiGlass

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Hardware setup

  • Batteries: Dual 250mAh Li-ion batteries (500mAh total, 3.7V-4.3V range)
  • Charging method: Connect USB-C cable to ESP32-S3 board
  • Charging LED: On-board LED indicates status

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Charging process

1

Connect the USB-C cable

Plug the USB-C cable into the ESP32-S3 board and your computer or charger.
2

Check the LED status

  • Red LED = Charging in progress
  • Green LED = Fully charged
3

Monitor progress

Use the charging command to verify charging is progressing normally:
4

Charging time

  • USB 2.0 port: ~1-1.5 hours full charge
  • USB 3.0 port: ~45-60 minutes
  • USB-C port: ~30-45 minutes

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Troubleshooting

Problem: Serial monitor connects but shows no output.Solutions:
  • Verify baud rate is 115200
  • Press the reset button on the ESP32 to restart
  • Try a different USB port or cable
  • Check the firmware flashed successfully
Problem: Battery percentage doesn’t change or shows incorrect values.Solutions:
  • Check voltage divider connections (A0 pin)
  • Verify battery is properly connected
  • Use status command to check raw voltage reading
  • Ensure resistor values are correct (169kΩ and 110kΩ)
Problem: Battery voltage doesn’t increase when connected to charger.Solutions:
  • Verify USB cable supports data and charging
  • Check charging LED on ESP32-S3 board
  • Try different USB port or charger
  • Verify battery connections are secure
  • Use charging command to monitor voltage over time
Problem: Battery readings fluctuate significantly.Solutions:
  • Check for loose connections in voltage divider circuit
  • Verify A0 pin is properly connected
  • Use charging command to take multiple readings
  • Ensure battery is properly secured

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Best practices

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Charging best practices

  • Charge when battery drops below 20% (3.8V)
  • Don’t let battery go below 3.5V (damages Li-ion cells)
  • Charge in moderate temperatures (10°C-40°C)
  • Use quality USB-C charger (5V, 1A minimum)

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Battery life optimization

  • Avoid complete discharge (stop using at 3.7V)
  • Charge regularly (don’t leave dead for days)
  • Store at 50% charge if not using for weeks
  • Optimize usage patterns:
    • Use light sleep mode when possible
    • Reduce photo frequency for all-day use
    • Disconnect when not needed to save power

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Monitoring schedule

  • Before use: Quick status check
  • During long sessions: Periodic status checks
  • While charging: Use charging command to verify progress
  • For troubleshooting: Use monitor for continuous tracking

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Next steps

Flash firmware

Update to the latest firmware version

Hardware assembly

Complete hardware setup guide