Arduino and reading from multiple USB connections I'm sending up a high-altitude balloon with an onboard Mighty Ohm Geiger Counter and some other sensors, all of which will be managed by an R Pi B+. I'll collect and store the data with the R Pi; all of that's fine.

In order to track and recover it, I'm using the HABDuino shield on an Arduino. It uses the APRS system and sends back short messages, giving the altitude, internal temp, my callsign, and coordinates. I'd like to add the Geiger counter's data to that, but I'll need to get it from the R Pi. 

Currently, I'm using an FTDI Friend to connect the Gieger counter to the R Pi, and getting the data from the serial port. I see here that I can connect the Arduino and Pi vai USB, but... since there's already a USB connection to the Gieger counter, will there be a conflict? Is that something that I can work around? 

Thanks for the help!
The FTDI should be showing up as /dev/ttyUSB0 on the Pi.

If you connect an Arduino as well it will show up as /dev/ttyACM0.

If you don't have enough USB sockets then just add a USB hub.