The following information is for the EMANT300, EMANT380

Wrong Analog Input reading when connected directly to DB25 connector

Question: I have used the simulator to read analog input. I've tested the training kit and it works well too.However, I am unable to read the value of a DC supply (1.5v Battery). The program showed that the voltage level is 2.5v, which is incorrect. A check with the mulitimeter showed that the battery has a potential of only 1.6v. I had connected the positive terminal to pin 11 (AIN0) and negative terminal to pin5 (AINCOM). The rest of the pins are not connected.

Is there any other pins I need to connect?

Answer: I assume you are connecting directly to the Dsub connector. Note that you have to connect also pin 4 REFIN- to pin 2 AGND. When you do this the internal reference is correctly set up.

Pin 2 is connected to pin 4 in our light application adaptor. Not all applications require this connection eg when using external references or making ratiometric measurements. But when you are using the internal reference (default), this must be done.