pwmFanControl64 is opening serial port /dev/ttyUSB0

[mgrouch]

ttyUSB0 is FTDI USB to serial adapter which has nothing to do with deskpi pro! Absolutely unrelated device.

lrwxrwxrwx  1 root root          7 Jul 21 01:33 /dev/ttyLYS_ftdi_AO009078 -> ttyUSB0

user@lysmarine:~ $ sudo lsof /dev/ttyUSB0
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
      Output information may be incomplete.
lsof: WARNING: can't stat() fuse.portal file system /run/user/1000/doc
      Output information may be incomplete.
COMMAND    PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
pwmFanCon 1509 root    3u   CHR  188,0      0t0  442 /dev/ttyUSB0

[f-io]

had the same problem, in my case ttyUSB0 is an USB-> serial -> EnOcean device. Please update your driver to check first and not just hardcode the port.

[paulwratt]

deskpi-config has this at line 14 (just like it is hard coded in line 16 of pwmControlFan.c):

serial_port='/dev/ttyUSB0'

I dont have any other USB TTY devices, so someone else will have to do some testing and /sys/class/ lookups to see where the DeskPi TTY device ends up when you have another USB TTY device plugged in

HINT: on RPi the USB devices are assigned from top-down, left -to-right , which corresponds to there USB ID numbers (lowest to highest). /dev/ttyUSB0 only gets assigned to the DeskPi if no other USB TTY devices have already been registered with the stack.

• If you have 1 USB TTY device plugged into either of the USB2 ports, it will get assigned /dev/ttyUSB0 before the DeskPi , which means the DeskPi will have /dev/ttyUSB1.
• if you have 1 USB TTY device plugged into the "other" USB3 port, that will get /dev/ttyUSB1 and DeskPi will still be on /dev/ttyUSB0
• if you have a hub on any of the USB2 ports, and multiple USB TTY devices, the DeskPi will get the last /dev/ttyUSB? device

NOTE: this does not take into account the front USB ports either, which is why some testing is needed. Also it might be possible to get (instead of put only) a value to the DeskPi USB TTY device, and get a known response back (eg like requesting the current PWM % maybe?), in which case you could blindly poll all the USB TTY devices , as long as you know what you are looking for per device.

[f-io]

@yoyojacky possible solution, use udev rules.

In this case within your install script:

#!/bin/bash

# create a udev rule for serial communication
UDEVRULE="ACTION==\"add\", ATTRS{idVendor}==\"1d6b\", ATTRS{idProduct}==\"0002\", SYMLINK+=\"deskPiPro\""
if [ ! -f /etc/udev/rules.d/10-local.rules ]; then
  echo -e $UDEVRULE >> /etc/udev/rules.d/10-local.rules
else
  checkResult=`grep "$UDEVRULE" /etc/udev/rules.d/10-local.rules`
  if [ $? -ne 0 ];  then
    echo -e $UDEVRULE >> /etc/udev/rules.d/10-local.rules
  fi
fi

The system will atomically create a symlink /dev/deskPiPro as soon as it finds a USB device with matching idVendor && idProduct. Now you can talk to the device by serialport serial_port='/dev/deskPiPro'

[yoyojacky]

yes, udev rule is better, I will try it on my test device, and update the script.

[yoyojacky]

@f-io I've tried this, but and adding a udev rule file to /etc/udev/rules.d/10-deskpi.rules and it can generate a symbolic link to /dev/ttyUSB0, like aliase name, but once I am trying to operate this device : /dev/deskPiPro it will not work properly. for example : echo "pwm_100" > /dev/deskPiPro
it will not trigger the fan spinning, but if i send the same command to /dev/ttyUSB0, it works fine . and i have change the owner of the /dev/deskPiPro to current user by using chown command and chmod command .

[yoyojacky]

had the same problem, in my case ttyUSB0 is an USB-> serial -> EnOcean device. Please update your driver to check first and not just hardcode the port.

Did you connect other USB device on your raspberry pi or just deskpi pro?