EL-1050 Interface Specs | LabJack
 

EL-1050 Interface Specs

2 posts / 0 new
Last post
JF
jfcaron's picture
EL-1050 Interface Specs

Hi, I am trying to use your EL-1050 humidity & temperature sensor with a TI MSP430 microcontroller.  I thought the interface would be SPI, given the number & labelling of the connections, but it's not described in the documentation.  Is it some weird special interface or is it indeed SPI?  If it's the latter, where can I find details about the data format?

LabJack Support
LabJack Support's picture
I just added a "Low-Level

I just added a "Low-Level Interface" section to the EI-1050 Datasheet:

https://labjack.com/support/datasheets/accessories/ei-1050

Here is what it says:

This information is mostly for talking to the EI-1050 with something other than a LabJack.

The EI-1050 uses the SHT11 from Sensirion.  The SHT11 speaks SBUS, which is similar to I2C but not exactly the same.  Details are provided by Sensirion.

The EI-1050 adds small RC filters (R=47 & C=1nF) to the Data and Clock lines.

The EI-1050 adds a MAX4514 switch to the Data line.  This switch is controlled by the Enable line on the EI-1050.  The Enable line has a 22k pull-up to Power.

The EI-1050 adds a 22k pull-up (to Power) to the Data line, but this is behind the switch so only connected when the probe is enabled.