Lascar Electronics EL-USB-2

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

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Protocol

Status structure

 // 0x03 packet type?
 uint8_t unknown1;

 // 0x00 ?
 uint8_t unknown2;

 // NULL-terminated device name, 15 chars max
 char device_name[16];

 // 0-23
 uint8_t start_time_hour;
 // 0-59
 uint8_t start_time_minute;
 // 0-59
 uint8_t start_time_second;

 // 1-31
 unit8_t start_date_day;
 // 1-12
 unit8_t start_date_month;
 // year - 2000
 unit8_t start_date_year;

 uint32_t unknown3;

 // in seconds, little-endian
 uint16_t samplerate;

 // little-endian
 uint16_t num_stored_samples;

 // alarm condition enable 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
 uint8_t alarm_flags;

 03 (03=logging?), 33 02 (02=stop?)
 uint8_t unknown4;

 // temp high alarm, (value + 40) * 2
 uint8_t alarm_temp_high;

 // temp low alarm, (value + 40) * 2
 uint8_t alarm_temp_low;

 // 00 00 00 3f, 00 00 80 3f
 uint32_t unknown6;

 // 00 00 20 c2
 uint32_t unknown7;

 // 00 00
 uint16_t unknown8;

 // temperature unit, little-endian (0=C, 1=Fahrenheit)
 uint16_t temp_unit;

 // ASCII, not NULL-terminated
 char firmware_version[4]

 // little-endian, displayed in decimal
 uint16_t serial_number;

 // 00 00
 uint16_t unknown13;

 // relative humidity high alarm, double value
 uint8_t alarm_rh_high;

 // relative humidity log alarm, double value
 uint8_t alarm_rh_low;

 // 00 00
 uint16_t unknown10;

 // 00 00 00 00
 uint32_t unknown11;

Resources

TODO.