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
Photos
Protocol
Commands
| Bytes
|
Command
|
| 0x00 0xff 0xff
|
Get device configuration structure.
A 3-byte header is returned first in which the first byte is 0x02, and the second and third bytes are the length of the configuration structure to follow, as a little-endian integer representing the number of bytes. Different devices in the EL-USB series have differently-sized configuration structures.
|
Device configuration structure
| Offset
|
Size
|
Value
|
| 0x00
|
1
|
Device type
| 1,2
|
EL-USB-1
|
| 3
|
EL-USB-2
|
| 4,6
|
EL-USB-3
|
| 5,7
|
EL-USB-4
|
| 8
|
EL-USB-LITE
|
| 9
|
EL-USB-CO
|
| 10
|
EL-USB-TC
|
| 11
|
EL-USB-CO300
|
| 12
|
EL-USB-2-LCD
|
| 13
|
EL-USB-2+
|
| 14
|
EL-USB-1-PRO
|
| 15
|
EL-USB-TC-LCD
|
| 16
|
EL-USB-2-LCD+
|
| 17
|
EL-USB-5
|
| 18
|
EL-USB-1-RCG
|
| 19
|
EL-USB-1-LCD
|
| 20
|
EL-OEM-3
|
| 21
|
EL-USB-1-LCD
|
|
| 0x01
|
1
|
Unused
|
| 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
|
Unsigned little-endian, seconds remaining until logging starts
|
| 0x1c
|
2
|
Unsigned little-endian, samplerate (seconds between samples)
|
| 0x1e
|
2
|
Unsigned little-endian, number of stored samples
|
| 0x20
|
1
|
| Bit
|
Alarm conditions bitfield (1=enable)
|
| 0
|
temperature high
|
| 1
|
temperature low
|
| 2
|
temperature high hold
|
| 3
|
temperature low hold
|
| 4
|
relative humidity high
|
| 5
|
relative humidity low
|
| 6
|
relative humidity high hold
|
| 7
|
relative humidity low hold
|
|
| 0x21
|
1
|
| Bit
|
bitfield
|
| 0
|
|
| 1
|
|
| 2
|
|
| 3
|
|
| 4
|
|
| 5
|
|
| 6
|
|
| 7
|
|
|
| 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
|
Device-specific configuration
|
| 0x30
|
4
|
Firmware version (ASCII, not NULL-terminated
|
| 0x34
|
2
|
Unsigned little-endian, serial number
|
| 0x36
|
2
|
unknown (00 00)
|
| 0x38
|
1
|
Relative humidity alarm high (value * 2)
|
| 0x39
|
1
|
Relative humidity alarm low (value * 2)
|
| 0x3a
|
2
|
unknown (00 00)
|
| 0x3c
|
4
|
unknown (00 00 00 00)
|
Device-specific information
The 16-bit field at offset 0x2e in the configuration structure has different meaning depending on which type of device sent it. It can be either a 16-bit little-endian integer or a bitfield.
| 0x00
|
Celcius
|
| 0x01
|
Fahrenheit
|
Resources
TODO.
