A web-based decoder for M3tering protocol payload data. This tool allows you to decode binary payloads from smart meters into human-readable format, supporting both hex and base64 input formats.
- Nonce: 32-bit counter for replay attack prevention
- Energy: Cumulative energy reading in kWh (6 decimal precision)
- Signature: 64-byte Ed25519 digital signature
- Voltage: Current voltage reading in volts (1 decimal precision)
- Device ID: 32-byte unique device identifier
- Longitude: Geographic longitude in degrees (5 decimal precision)
- Latitude: Geographic latitude in degrees (5 decimal precision)
0000000000001aea1b0bb5a800ab9647c6bdaae5b915d1a1cfa406cc2129fb94d5841d73fca553329e1fe9c7cf52df89ff9086ba5929825739f72b55f1538448e22baaedf454db050082356963ce530d3dc24cbb2c0870923171442efbb202de75b0572da97b22de9767
AAAAAAAAGuobC7WoAKuWR8a9quW5FdGhz6QGzCEp+5TVhB1z/KVTMp4f6cfPUt+J/5CGulkpglc59ytV8VOESOIrqu30VNsFAII1aWPOUw09wky7LAhwkjFxRC77sgLedbBXLal7It6XZw==
The M3ter payload follows a specific binary format:
Offset Length Field Description
------ ------ ----------- ----------------------------------
0 4 Nonce Big-endian uint32 counter
4 4 Energy Big-endian uint32 (kWh × 10⁶)
8 64 Signature Ed25519 signature over bytes 0-7
[72] 2 Voltage Big-endian uint16 (V × 10)
[74] 32 Device ID 32-byte identifier
[106] 3 Longitude Signed 24-bit int (degrees × 10⁵)
[109] 3 Latitude Signed 24-bit int (degrees × 10⁵)
- Integers: Big-endian byte order
- Energy: Multiplied by 10⁶ for 6 decimal places precision
- Voltage: Multiplied by 10 for 1 decimal place precision
- Coordinates: Multiplied by 10⁵ for 5 decimal places precision
- Signature: Ed25519 algorithm over nonce + energy bytes
Note: This decoder is for development and testing purposes. Always verify decoded data against your specific implementation requirements.