I'm using ROS melodic with ubuntu 18.04 running on a Thinkpad. I want to install rosserial for my arduino uno with this tutorial: http://wiki.ros.org/rosserial_arduino/Tutorials/Arduino%20IDE%20Setup

When i'm running:

sudo apt-get install ros-melodic-rosserial-arduino  

i get these errors:

[sudo] password for colidar:
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  arduino-core avr-libc avrdude binutils-avr gcc-avr libftdi1 libusb-0.1-4
  ros-melodic-rosserial-client ros-melodic-rosserial-msgs
  ros-melodic-rosserial-python
Suggested packages:
  arduino-mk avrdude-doc task-c-devel gcc-doc
The following NEW packages will be installed:
  arduino-core avr-libc avrdude binutils-avr gcc-avr libftdi1 libusb-0.1-4
  ros-melodic-rosserial-arduino ros-melodic-rosserial-client
  ros-melodic-rosserial-msgs ros-melodic-rosserial-python
0 upgraded, 11 newly installed, 0 to remove and 509 not upgraded.
Need to get 22,5 MB of archives.
After this operation, 137 MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Get:1 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 binutils-avr amd64 2.26.20160125+Atmel3.6.0-1 [1.475 kB]
Err:2 http://packages.ros.org/ros/ubuntu bionic/main amd64 ros-melodic-rosserial-msgs amd64 0.8.0-0bionic.20190318.181339
  404  Not Found [IP: 2600:3402:200:227::2 80]
Err:3 http://packages.ros.org/ros/ubuntu bionic/main amd64 ros-melodic-rosserial-client amd64 0.8.0-0bionic.20190320.170619
  404  Not Found [IP: 2600:3402:200:227::2 80]
Err:4 http://packages.ros.org/ros/ubuntu bionic/main amd64 ros-melodic-rosserial-python amd64 0.8.0-0bionic.20190320.153333
  404  Not Found [IP: 2600:3402:200:227::2 80]
Err:5 http://packages.ros.org/ros/ubuntu bionic/main amd64 ros-melodic-rosserial-arduino amd64 0.8.0-0bionic.20190320.171059
  404  Not Found [IP: 2600:3402:200:227::2 80]
Get:6 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 gcc-avr amd64 1:5.4.0+Atmel3.6.0-1build1 [15,1 MB]
Get:7 http://de.archive.ubuntu.com/ubuntu bionic/main amd64 libusb-0.1-4 amd64 2:0.1.12-31 [17,1 kB]
Get:8 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 libftdi1 amd64 0.20-4build3 [15,0 kB]
Get:9 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 avrdude amd64 6.3-4 [302 kB]
Get:10 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 avr-libc all 1:2.0.0+Atmel3.6.0-1 [4.872 kB]
Get:11 http://de.archive.ubuntu.com/ubuntu bionic/universe amd64 arduino-core all 2:1.0.5+dfsg2-4.1 [626 kB]
Fetched 22,4 MB in 17s (1.333 kB/s)                                            
E: Failed to fetch http://packages.ros.org/ros/ubuntu/pool/main/r/ros-melodic-rosserial-msgs/ros-melodic-rosserial-msgs_0.8.0-0bionic.20190318.181339_amd64.deb  404  Not Found [IP: 2600:3402:200:227::2 80]
E: Failed to fetch http://packages.ros.org/ros/ubuntu/pool/main/r/ros-melodic-rosserial-client/ros-melodic-rosserial-client_0.8.0-0bionic.20190320.170619_amd64.deb  404  Not Found [IP: 2600:3402:200:227::2 80]
E: Failed to fetch http://packages.ros.org/ros/ubuntu/pool/main/r/ros-melodic-rosserial-python/ros-melodic-rosserial-python_0.8.0-0bionic.20190320.153333_amd64.deb  404  Not Found [IP: 2600:3402:200:227::2 80]
E: Failed to fetch http://packages.ros.org/ros/ubuntu/pool/main/r/ros-melodic-rosserial-arduino/ros-melodic-rosserial-arduino_0.8.0-0bionic.20190320.171059_amd64.deb  404  Not Found [IP: 2600:3402:200:227::2 80]
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

also

sudo apt-get install ros-melodic-rosserial-arduino 

doesn't work.

I have already tried:

source /opt/ros/melodic/setup.bash
sudo apt-get update    
sudo apt-get install arduino     
sudo apt install python-rosinstall python-rosinstall-generator python-wstool build-essential    
rosdep update