Ha you use the pocketchip to do this.
In this case, first tell me if you have midi stuff when you launch picoloop on the pocketchip.
It's on the first screen when you have launch the app.
I don't remember if the software was build with midi enable on this platform.
If it is the case, then it should work.
If you want to use pc and pocketchip , pc master, pocketchip slave, then you will need two of this usb cable and female-female connector.
In this day, I work on the raspiboy which is a raspberry pi zero. Near the same performance as the pocketchip and raspberry pi 1. And picoloop work on raspberry pi. Today it doesn't work on raspiboy, need to handle the joystick and find a good way to autoboot the software.