EV3 image

The ev3dev2simulator emulates the python3 ev3dev2 library version '2.0.0beta5' to let your ev3dev2 program interact with the simulator.

On the EV3 brick it is recommended to have the same python3 ev3dev2 library version '2.0.0beta5' installed.

The stable release of ev3dev at 2019-10-23 (alternative link) comes with the python3 ev3dev2 library version '2.0.0beta5'. This image has the kernel version '4.14.117-ev3dev-2.3.4-ev3'.

You can see the current kernel version of the ev3dev os installed on your ev3 by going to the "about" menu, and then scroll down until you see the "Kernel:" label. It should look like:

You can verify versions also by logging into the ev3 with ssh:

$ ssh [email protected] # password: maker

    
robot@ev3dev:~$ printf "\n\nkernel version(contains ev3dev os version)\n---------------------------------------\n"; uname -a ; printf "\n\nrelease version(gefile)\n---------------------------------------\n"; cat /etc/*rel* ;printf "\n\nversion of the python ev3dev2 library\n---------------------------------------\n";cat /usr/lib/python3/dist-packages/ev3dev2/version.py; printf "\n\n" ;


kernel version(contains ev3dev os version)
---------------------------------------
Linux ev3dev 4.14.117-ev3dev-2.3.4-ev3 #1 PREEMPT Thu May 9 15:13:01 CDT 2019 armv5tejl GNU/Linux


release version(contains orig. name of imagefile)
---------------------------------------
ev3dev-stretch-ev3-generic-2019-10-23                <== original name of image file use for sdcard
PRETTY_NAME="ev3dev-stretch"
NAME="ev3dev-stretch"
ID=ev3dev
ID_LIKE=debian
HOME_URL="http://www.ev3dev.org"
SUPPORT_URL="http://www.ev3dev.org/support"
BUG_REPORT_URL="https://github.com/ev3dev/ev3dev/issues"


version of the python ev3dev2 library
---------------------------------------
__version__ = '2.0.0beta5'           

Fix for bluetooth not available problem

Problem

Sometimes after powering up the EV3, in the menu when you choose "Wireless and Networks" -> "Bluetooth", the screen will prompt “Not available”. If you meet this condition, the only fix was to just shut down your EV3 and start up again. Hoping that the reboot fixes it. Sometimes we needed to reboot several times!

Occurs in image: https://github.com/ev3dev/ev3dev/releases/download/ev3dev-stretch-2019-10-23/ev3dev-stretch-ev3-generic-2019-10-23.zip

solution

github issue: https://github.com/ev3dev/ev3dev/issues/1314

There is a systemd-rfkill service. We don't need this since ConnMan will take care of this already. So we should be able to do the following:

  sudo systemctl mask systemd-rfkill.service
  sudo systemctl mask systemd-rfkill.socket

This should make sure that systemd doesn't try to mess with with the Bluetooth adapter.

ssh login

To ease the login to EV3 in usb-tethering mode with ssh I have the following configure in my ~/.ssh/config

# using usb tethering
Host ev3
   Hostname 192.168.0.1
   User robot
   #password: maker

I then login with

ssh ev3    # supply password 'maker'

change hostname EV3

Using the commandline

sudo hostnamectl set-hostname ev3dev1

Using a config utility:

sudo ev3dev-config
 => advanced option => change hostname   => then exit,   and reboot

then reboot the EV3 and the hostname will be changed.

IMPORTANT: Don't use the 'hostname' command to set the hostname of the ev3, because that is only temporarily and forgotten after a reboot.

fetch bluetooth mac-address

Login with ssh on the EV3 and run the 'bluetoothctl' command to retreive th bluetooth mac-address of the EV3:

robot@ev3dev16:~$ bluetoothctl
...

[bluetooth]# list
Controller 78:DB:2F:29:F0:39 ev3dev16 [default]