The XBIB and Grove XBee Interface boards have pull-up resistors that can override the internal pull-up resistor IO pin settings of the XBee module. This is most commonly seen on pins 5, 6, 7, 8, and 9 on through-hole modules. However, this behavior is not seen when connecting to the XBee module with wires such as with a breadboard. If you need to use any of the above cited IO pins, it is recommended to use the XBee module in your own hardware setup, and not on the XBIB or Grove XBee Interface boards.
Jan 08, 2020