Lascar Electronics EL-USB-2
The Lascar Electronics EL-USB-2 is a USB-based temperature and humidity logger.
See Lascar Electronics EL-USB-2/Info for more details (such as lsusb -vvv output) about the device.
Hardware
- Silicon Labs C8051F321 8051-based USB microcontroller
- Microchip 24LC256 32kB EEPROM
- Sensiron SHT11 Temperature/humidity sensor
Photos
Protocol
Status structure
| Offset | Size | Value |
|---|---|---|
| 0x00 | 2 | unsigned little-endian, device type? 3=EL-USB-2, 9=EL-USB-CO |
| 0x02 | 16 | NULL-terminated device name, 15 chars max |
| 0x12 | 1 | Start time, hour (0-23) |
| 0x13 | 1 | Start time, minute (0-59) |
| 0x14 | 1 | Start time, second (0-59) |
| 0x15 | 1 | Start date, day (1-31) |
| 0x16 | 1 | Start date, month (1-12) |
| 0x17 | 1 | Start date, year (year - 2000) |
| 0x18 | 4 | unknown |
| 0x1c | 2 | unsigned, little-endian samplerate (seconds between samples) |
| 0x1e | 2 | unsigned, little-endian number of stored samples |
| 0x20 | 1 | alarm conditions bitfield |
| 0x21 | 1 | current status? (2=stopped, 3=logging) |
| 0x22 | 1 | temperature alarm high (value + 40) * 2 |
| 0x23 | 1 | temperature alarm low (value + 40) * 2 |
| 0x24 | 4 | unknown (00 00 00 3f, 00 00 80 3f) |
| 0x28 | 4 | unknown (00 00 20 c2) |
| 0x2c | 2 | unknown (00 00) |
| 0x2e | 2 | unknown (possible temp unit, 00 00=C, 01 00=F) |
| 0x30 | 4 | firmware version (ASCII, not NULL-terminated |
| 0x24 | 2 | unsigned little-endian, serial number |
| 0x26 | 2 | unknown (00 00) |
| 0x28 | 1 | relative humidity alarm high (value * 2) |
| 0x29 | 1 | relative humidity alarm low (value * 2) |
| 0x2a | 2 | unknown (00 00) |
| 0x2c | 4 | unknown (00 00 00 00) |
The rest of the 128-byte payload is padded with 0xff.
Resources
TODO.