5.6 Digital I/O Pull-Up / Pull-Down

The 24 digital I/O lines on I/O header J4 are connected to 10K resistors that can be configured for either pull-up or pull-down. All resistors are configured in the same way. Jumper block J8 in the lower left corner of the board is used for configuration. To set the pull direction, install a jumper above the mark +5 or GND as desired. The +5 and Ground signals are wired to opposite corners of J8 to prevent accidentally shorting out the power supply by inserting the jumper incorrectly. DO NOT install jumpers in both +5 and GND locations simultaneously.