Instructions

Device Operations

• Power ON: Short press the power button
• Power OFF: Short press the power button
• Normal mode: The default state after powering on. Indicates the device is ready to connect
• Pairing mode: Press and hold the power button until the LED starts blinking blue

LED Indicators

Color	Description
Breathing white	Normal mode (Ready to connect)
Blinking blue	Pairing mode
Solid green	Pairing successful
Solid orange	Charging
Blinking white	Firmware update (OTA) in progress

Device Connection Process

Check the required permissions

• App Bluetooth permission is granted and the system Bluetooth service is enabled
• App Location permission is granted and the system Location service is enabled (Android 6–11)
• App has Scan nearby Bluetooth devices and Connect Bluetooth devices permissions (Android 12+)

Key Concepts

Before understanding the connection process, it is important to distinguish between the following two concepts:

1. Current Device Mode

Whether the device is in Pairing mode or Normal mode can only be identified during the BLE scanning phase. This status only represents the device's current broadcast mode and is solely used to determine which connection flow to follow — it cannot be used to determine whether the device has previously been paired with the current host device.

2. Local Pairing Record

The pairing relationship is maintained locally by the App. The device does not provide the ability to query whether it has been previously paired. The local record is primarily used to determine which device mode to look for during scanning:

• No local pairing record → Scan for devices in Pairing mode
• Local pairing record exists → Scan for devices in Normal mode

Note: The device stores up to 3 most recent pairing records and does not maintain per-host pairing history. If the device has been paired with other host devices, existing pairing information may be overwritten, causing the current host to be treated as "no pairing record" and requiring re-pairing.

1. No Local Pairing Record

1. Scan for devices in Pairing mode
2. When a device in Pairing mode is found, tap to establish a BLE connection
3. Send the pair command to initiate pairing (establish a pairing relationship)
4. Pairing successful: Save the local pairing record and proceed with your application flow
5. Pairing failed: Error code 3, prompt the user with "Pairing failed" and guide them to retry

2. Local Pairing Record Exists

1. Scan for devices in Normal mode
2. When your bonded device is found in Normal mode, establish a BLE connection
3. Send the check command to verify pairing information (validate the existing pairing relationship)
4. Verification successful: Proceed with your application flow
5. Verification failed: Error code 4, prompt the user with "Pairing verification failed" and guide them to re-pair

Error Codes

Error Code	Scenario	Description
3	pair failed	Pairing command execution failed, prompt the user to retry
4	check failed	Pairing verification failed, guide the user to re-enter the pairing flow

Note

Whether to send pair or check is determined by the scanned device's broadcast mode, and it must match the current expected flow. If the command does not match the device mode, the device will return the corresponding error code.

Additional Notes

• Whether pair or check fails, the device will return a specific error code that the App can use for prompts or retry guidance
• pair and check correspond to "establishing a pairing relationship" and "verifying an existing pairing relationship" respectively — they are two separate commands
• The device can only connect to one host device at a time. If the device is already connected to another host, it will not appear in scans
• Do not automatically connect to devices in Pairing mode to avoid multiple hosts competing to connect to the same device
• The LED turns green after successful pairing or verification
• Android has a scan frequency limit: do not exceed 5 scans every 30 seconds, otherwise the device may not appear in scan results
• Some Android devices do not return scan results when the app is in the background, such as Xiaomi and Redmi
• The host device should disconnect the GATT connection before the application terminates

OTA - Device Firmware Upgrade

OTA using the OxyZen App (Recommended)

If the device needs to be upgraded, you will receive a prompt after connecting.

• App Store
• sj.qq.com

OTA using the nRF Connect App

1. Download and install the nRF Connect App
2. Open the nRF Connect App, tap Scan, then tap Connect
3. After the device connects successfully, tap DFU in the upper right corner, select Select File, choose the upgrade file, and wait for the upgrade to complete
4. To verify the firmware version: go to Device Information → Firmware Revision String, and tap the ⬇️ button

• OTA video

• OTA screenshot