I'm trying to connect to the DrDAQ external input. I understand that the manual shows the pin numbers from left looking towards the card, component side up. Using the PicoScope I observe noise when I touch pin 3 (Auto detect) but not when I touch pin 1 (signal). The Y-axis is set to Ext1 x1.
When I connect a 1.5V battery between pin 1 and 2 I see no change in the scope trace (stays at zero), when I connect 3 and 2 I get a reading of about 100. I do not use a auto scale resistor.
I have two questions: Do I understand the no 1 pin position of the external connector correctly?
Why do I get a reading of 100 when the input voltage is about 1.5V?