I've been trying to mod an old Roomba 400 series (model #4220) by adding a Raspberry Pi to it.

I have the Raspberry Pi communicating over serial with the EZSync018 cable. I have everything working, except that I can't seem to wake the Roomba up after it goes to sleep. I try pulsing the DD (pin 5) with pyserial like so:

import serial
import time

ser = serial.Serial("/dev/ttyUSB0",57600)


Even sending the START or CONTROL commands don't seem to do anything if the Roomba is asleep. If I press the power button it turns on and accepts commands normally, but I want it to be able to wake up on its own.

I have a suspicion that the cable might have a wire switched, but I wanted to post here to see if anyone else had any experience or ideas before I mutilate a perfectly good sync cable.

Any help / feedback is greatly appreciated!

  • $\begingroup$ Did you manage to resolve this problem? Was it a bad cable? $\endgroup$ Jun 30, 2023 at 10:10
  • 1
    $\begingroup$ I have a suspicion that the cable might have a wire switched This can be checked pretty quickly with a multimeter by doing a continuity check across the cable. $\endgroup$
    – Chuck
    Jul 1, 2023 at 6:31
  • 1
    $\begingroup$ @Chuck - there is a built-in FTDI IC which probably/might hamper testing with a multimeter, unless the shrouding is peeled back. However, if the OP is going to mutilate the cable anyway, then yes, it is a good quick test. $\endgroup$ Jul 1, 2023 at 10:38
  • 1
    $\begingroup$ Ah fair enough! I'll admit to not having this device and didn't lookup the cable before commenting :-$ $\endgroup$
    – Chuck
    Jul 1, 2023 at 18:50


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