Time Calibration QR Tool
Published 2026-09-09
中ENGenerate a signed system-time QR code online for devices to scan and calibrate their clock; auto-refreshes every second, no installation needed.
The time-calibration QR tool lets you set/correct device clocks in batch or one by one: the device scans the QR code, parses the signed system time it carries, verifies the signature, then updates its local clock.
Step 1: Generate
1. Open the tool (Technical Docs → Online Tools → Time Calibration QR Tool);
2. Enter the signing password agreed with the device side (the default matches the factory convention — change it and sync to devices as needed);
3. Scan the QR code with the device; after signature verification, the device calibrates its clock to the encoded time;
4. The QR code refreshes every second, so the time is always the system time at the moment of generation.
Payload Format
The payload consists of a protocol header + system time + HMAC-MD5 signature:
___VBAR_CONFIG_V1.1.0___{systemtime='YYYY-MM-DD HH:mm:ss'}--<Base64(HMAC-MD5)>
Security Notes
The key participates in HMAC-MD5 signing and the device verifies with the same key; everything runs locally in your browser and no data is uploaded.
FAQ
How often does the time-calibration QR code refresh?
It refreshes every second, so the encoded time is always the system time at generation.
What is the signing password?
The password you enter when generating; it signs the payload with HMAC-MD5 and the device must verify with the same key.
Does the QR code leak system information?
It only contains the protocol header, the current system time and the signature — no network or account information.