PyPilot doesn't work after upgrade

[seandepagnier]

are you on tinycore then?  I think the troubleshooting doesn't assume this.   You might need to issues:

The other way is just put a fresh tinypilot image on sd card.   It will work if the connections are right and the motor controller is ok.

I use tinypilot_28062019.img.xz, I've just installed on a new SD card

There is a newer image but that is probably not the problem. 
The log you posted before inidcated that pypilot was already running, so of course /dev/ttyAMA0 was busy and not available.


Try booting the tinypilot, and let us see /var/log/pypilot/current.   Don't run pypilot manually since it automatically is started at boot.
If the servo is not detected on /dev/ttyAMA0 (make sure motor controller is powered)  then try disconnecting power to the motor controller and try with a usb cable.   If this works, then you know the controller works but communication is bad.   Otherwise likely the controller has a problem.