TM2 Output (sometimes)

GPS/GNSS Development Boards
1

I have a SparkFun module with the F9P. I’m having an issue when I pull EXTINT0 low with just a resistor. If I solder a resistor as shown in the attachment then I don’t get any data output.

If I replace the resistor with a decade box with a value of 20kΩ then I start seeing data being output, which is what I want. Why does just using a resistor not work and the decade box does work? I can see that I stand to learn something here and welcome any assistance.

Regards,

Chris

SparkFun_ZED-F9P.jpg

2

The module might be looking for a high to low transition on that pin rather than an always low signal. If you solder a resistor, the pin is always low, but with a decade box, it’s high until you attach the box and low afterwards.