How to connect a MH Z19B to PI B+ when the GPIO is taken up?

I have been given a MH Z19B sensor, and I am running hassio on a Pi B+. Usually you can plug the MH Z19B into the GPIO, however, I already have a RaspBee (https://www.dresden-elektronik.de/funktechnik/products/boards/development-boards/raspbee/description/?L=1) plugged into my Pi, so the GPIO board is taken up.

Are there any other options to get the MH Z19B connected with the Pi? Of course I have the RaspBee so it would be ideal to get it hooked up with the zigbee network. Or perhaps through USB since I have spare USB ports.

Any ideas would be appreciated!