I was having trouble getting Observer program to run. This likely would have applied to all but I didn’t try that before making the change.
I was getting:
could not open port /dev/ttyS0
I had enable_uart=1 in the boot config text file.
When I go to /dev/ I do see ttyAMA0, and do NOT see ttyS0. Even with enable_uart=1.
I tried multiple things and ultimately went in to sphero_sdk/observer/client/dal/serial_observer_port.py and changed the serial port from ttyS0 to serial0 and now it works.
I don’t know if this will apply to everyone. But I can now set_all_leds.py which was basically my Hello World.