Colead SL-5868P
Jump to navigation
Jump to search
The Colead SL5868P is an inexpensive sound level meter with RS232 capability. It has Lp and Leq measurement modes, and can trigger alarm conditions based on a configured level.
It is rebranded under many names, but appears to generally have the SL-5868P model designation. It's available for under $100.
Hardware
- Nuvoton W78E052D 8-bit microcontroller
- Holtek HT1621B LCD driver
Photos
Protocol
TODO: serialcomm
The meter sends two measurements per second. When a new measurement is ready, the device sends 0x10. The PC responds with 0x20, which causes the device to transmit a 10-byte structure containing configuration and measurement.
Commands
| Command | Direction | Description |
|---|---|---|
| 0x10 | Device -> PC | Measurement ready |
| 0x20 | PC -> Device | Send measurement |
Data structure
| Byte | Description |
|---|---|
| 0 | ? |
| 1 | ? |
| 2 | ? |
| 3 | ? |
| 4 | ? |
| 5 | BCD-encoded dB value, most significant digit |
| 6 | BCD-encoded dB value, second digit |
| 7 | BCD-encoded dB value, least significant digit |
| 8 | Always 0x01 |
| 9 | Checksum: sum of bytes 0-8 |