/dev/tty_in1: No such file or directory and motor is not spinning

[asanebub]

Hello @bmegli,

I'm trying to test the xv11 lidar-sensor with ev3, like it's mentioned here: https://www.ev3dev.org/docs/tutorials/using-xv11-lidar/:

When I'm doing: echo other-uart > /sys/class/lego-port/port0/mode, then there isn't a folder /dev/tty_in1. I just have: tty_ev3-ports:in1

Here you can see the output of the commands:

Additionally the motor is not spinning, when I do:

echo 44 > /sys/class/dc-motor/motor0/duty_cycle_sp
echo run-direct > /sys/class/dc-motor/motor0/command

How can I solve these problems?

[bmegli]

First - this program was written more than 4 years ago.\ Many ev3dev versions were released during this period.

Some things (obviously tty paths) changed.

I am assuming you are using the ev3dev-strech.

The motor

I have just tested it with ev3dev-strech-2019-10-29.

Initial setup (once after boot)

echo dc-motor > /sys/class/lego-port/port4/mode #for output A, otherwise adjust the port number
dmesg | tail #you can see here which number the dc-motor  was created with
cat /sys/class/dc-motor/motorX/address # where X is the motor number, make sure the address matches the port

Controlling the motor

Assuming it is the motor0

echo 44 > /sys/class/dc-motor/motor0/duty_cycle_sp
echo run-direct > /sys/class/dc-motor/motor0/command

If it doesn't spin try with -44.

E.g.

echo -44 > /sys/class/dc-motor/motor0/duty_cycle_sp
echo run-direct > /sys/class/dc-motor/motor0/command

It is critical that the motor spins counter-clockwise.

If it doesn't work make sure it is soldered correctly.

See also #1.

The sensor

I have also just tested it with ev3dev-strech-2019-10-29.

Yes, obviously you are right.

The notation in ev3dev-stretch is tty_ev3-ports:in1

So it will be:

Once after boot:

echo other-uart > /sys/class/lego-port/port0/mode

And to read from lidar:

./xv11test /dev/tty_ev3-ports\:in1

Note that, for this to work it is critical that motor spins CCW.

[asanebub]

It worked with ./xv11test /dev/tty_ev3-ports\:in1

Thank you! :)