I understand that on powerup all IO are defined as inputs. I am using AUX #0 (JP4) bits 18-25 and using AUX #1 (JP6) bits 26-35. Bits 24 & 25 and bits 34 & 35 come up as inputs and respond to input data. All others do not act like inputs and their voltage is ~ 0.12 volts. They can be made outputs and are good outputs. 3K pull-ups to 3.3V are used on all bits with NO switch contacts to common. The pull-ups do not bring the voltage up.
Group: DynoMotion
Message: 850
From: Tom Kerekes
Date: 1/6/2011
Subject: Re: Some IO bits won't become INPUTS
Hi Bob,
The first 8 bits on both Aux #0 and Aux #1 have 150 ohm termination (pull down resistors). So about 16ma is needed to pull them high. Sorry that isn't documented better.