Pan and tilt facetracking I/O error


HI, I am super frustrated and have tried everything possible to get this running for a university project.
This is the post I’m following -

The error i’m getting after I ran everything is

pi@raspberrypi:~/PanTiltFacetracker $ sudo python ./
Traceback (most recent call last):
File “./”, line 4, in
from pantilt import *
File “/home/pi/PanTiltFacetracker/”, line 7, in
servo = PWM.PCA9685()
File “/usr/local/lib/python2.7/dist-packages/Adafruit_PCA9685/”, line 75, in init
self.set_all_pwm(0, 0)
File “/usr/local/lib/python2.7/dist-packages/Adafruit_PCA9685/”, line 111, in set_all_pwm
self._device.write8(ALL_LED_ON_L, on & 0xFF)
File “/usr/local/lib/python2.7/dist-packages/Adafruit_GPIO/”, line 114, in write8
self._bus.write_byte_data(self._address, register, value)
File “/usr/local/lib/python2.7/dist-packages/Adafruit_PureIO/”, line 236, in write_byte_data
IOError: [Errno 121] Remote I/O error

is there anything I’m doing wrong here? I’m so confused, I did everything step by step.


I don’t have this pan tilt, but it sounds like the code tries to connect to a port that you didn’t connect.
Did you checked the wiring ?


Are you using a PA9685 servo driver or a Pan Tilt HAT?