Tuesday, May 3, 2016

Minecraft on Raspberry Pi Zero using OTG USB Ethernet connection with RealVNC server and client


In my previous post I connected to a Raspberry Pi 3 using RealVNC to connected over Ethernet.
To achieve this you would need:
Laptop
Raspberry Pi
PSU for Pi
Ethernet cable

What if you could replace the PSU and Ethernet with just a microUSB cable and replace the Pi3 by a PiZero.
Well, this is absolutely possible and quite simple due to the hard work of a number of people including Andrew Mulholland who created a guide on setting up Ethernet over USB using OTG that I hope to make even more simple here. Then it's a matter of installing RealVNC to get the Raspbian desktop on your laptop.

OTG stands for On-The-Go or it's full name USB On-The-Go
Put simply OTG allows a USB device to act like a host and have peripherals  such as keyboard and external storage attached to the device or act like a slave so it can be a network device or a mass storage device.
This is most used on phones an tablets where it's great to be able to plug in a USB stick and access the files (host) or plug the phone into your computer and download the files (slave)

For OTG is enabled by the ID-pin which is available on the PiZero as the USB port is directly connected to SOC and it uses a microUSB connector which has the extra pin for the ID.

Back in December Andrew posted a guide on setting up OTG.
It includes a lot extra information that is worth reading and understanding, but here I want to just do the facts and steps needed to enable Ethernet over USB.

I'm assuming you have already installed Raspbian on your PiZero 

Next you need your PiZero to be connected to the network to be able to download and install some files. For this I used an Wii USB Ethernet adapter.  This adapter is supported by default. They're about £10 on eBay.  Just search Wii USB Ethernet.

With the PiZero connected to the network I found the Pis IP address using Fing on my phone.
With the IP address known I used putty to ssh in. (Yes, this is the correct link for downloading)

Once logged in do the usual housekeeping.
sudo raspi-config to expand the filesystem and set GPU memory to 128MB
sudo apt-get update
sudo apt-get upgrade

Then it's a matter of running the following commands one after another to get Ethernet over USB set up. Andrew's guide explains what they do and also the other OTG options available.


sudo BRANCH=next rpi-update

echo "dtoverlay=dwc2" | sudo tee -a /boot/config.txt

echo "dwc2" | sudo tee -a /etc/modules

echo "g_ether" | sudo tee -a /etc/modules

echo -e "interface usb0 \nstatic ip_address=169.254.64.64" | sudo tee -a /etc/dhcpcd.conf

Now Ethernet over USB should be set up.

Next RealVNC server needs to be installed.  The guide for installing the latest Alpha that supports Minecraft can be  found here. https://github.com/RealVNC/raspi-preview

With the relevant commands being:
curl -OL https://github.com/RealVNC/raspi-preview/releases/download/5.3.1.18206/VNC-Server-5.3.1-raspi-alpha1.deb

sudo dpkg -i VNC-Server-5.3.1-raspi-alpha1.deb

sudo systemctl enable vncserver-x11-serviced.service

These install RealVNC server and enable it as a service that starts at boot up.

Shutdown your PiZero using
sudo shutdown 0

Unplug the cabled.
Plug single microUSB cable into the USB port on the PiZero and the other end into your laptop USB port. The PiZero uses so little power it can safely be powered from the laptop USB with no issues.
Mine laptop is running Windows 10 and the device is automatically detected and the drivers installed.  I didn't have to do anything.
This creates a new Ethernet device.

Download and install RealVNC Viewer 

Run RealVNC Viewer on your laptop and enter the fixed IP address of 169.254.64.64 used when setting up the PiZero.
It will ask for your login. On mine it defaults to the laptop username. so, just change to pi/raspberry assuming you haven't changed it.

RealVNC should now login to the PiZero.
It's that simple.

RealVNC recommend some optimisation that I definitely found to improve performance.

On the VNC Viewer toolbar (top of the Window), click the Options button.
Click Advanced..., then the Expert tab.
Set PreferredEncoding to JPEG, AutoSelect to False, and ColorLevel to Full

These changes really make RealVNC smoother.

If using Minecraft you have to make one more selection.
Press [F8] to go back to the menu and select Relative Pointer Motion
Then start Minecraft as normal.
All should work perfectly.

You will notice that the RealVNC window is quite small this is because there is no resolution details set by a display so the Raspberry Pi defaults to 640x480 as the safest mode.

To increase the resolution you have to make some minor changes to config.txt
RealVNC give full details on this on the following support page

But to put it simply to set the resolution to 800x600 do the following

Open a terminal window
cd /boot
sudo cp config.txt config.txt.backup
sudo nano config.txt

This makes a backup of config.txt and then opens it with nano

Remove the # in front of hdmi_force_hotplug and set it to 1
hdmi_force_hotplug=1


Enter the following line into config.txt

hdmi_ignore_edid=0xa5000080


No idea what it does and even RealVNC describe it as better safe than sorry.  I've run without it and it worked.

Remove the # in front of hdmi_group and set it to 2.
hdmi_group=2

Remove the # in front of hdmi_mode and set it to 9 which is the value for 800x600.
You can look up all the values and adjust according to your needs on the elinux.org page

Press [CTRL]-[x] to exit.
Select y for saving changes and then press [Enter]

Now your config.txt is up to date.

Restart the Raspberry Pi and it will restart with a resolution of 800x600 rather than 640x480 making everything a little easier.
If you want a higher resolution then hdmi_mode=16 is 1024x768 and hdmi_mode=39 is 1360x768

Finally, here is a (low quality recorded from my phone) video of it all running. You can see the speed is good and even programming in Python works well.


Sunday, May 1, 2016

Using only Ethernet cable to connect Windows computer to Raspberry Pi

The Raspberry Pi is designed to be used a standalone computer only needed a monitor, keyboard and mouse to function.

There are many guides on how to SSH or VNC into the Raspberry Pi with the network set up usually using a router.

Well, what if you don't have a router because you're at an event or you don't want to put your Pi on the network.  It's fun at a Raspberry Jam to see all the Raspberry Pi's with the same name and the same user name and password on a network.

For this situation there is a really simple solution.  You give the computer's Ethernet port a fixed IP and you do the same on the Pi.
The great thing with this is the computer and the Pi can still connect to the available network over wifi and if available connect to the internet. 


I use this configuration a lot for simple python development where a full GUI isn't needed and since my ability to remember things is limited access to the internet from my laptop is essential for tips and trouble shooting.


For this to work the IP addresses you give the Ethernet ports cannot be on the same subnet as the router (if there is one)|
To check this on Windows do an ipconfig

You'll get something like below which shows the Wireless has an IP address of 192.168.0.11 with a subnet mask of 255.255.255.0 and a gateway of 19.168.0.1

The subnet mask says what range is usable.
In this case 192.168.0.1 - 192.168.0.255 are all in the subnet so are part of this routers control. 
You can limit the IP controlled by the router, but for this it's safer to assume ALL IP addresses from 1-255 are out of bounds. There are more than enough other IP addresses to use safely

Windows IP Configuration

Ethernet adapter Ethernet:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :

Wireless LAN adapter Local Area Connection* 3:
   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :

Wireless LAN adapter Local Area Connection* 5:
   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :

Wireless LAN adapter Wi-Fi:
   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::501b:b10b:e1c4:62ff%5
   IPv4 Address. . . . . . . . . . . : 192.168.0.11
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.0.1

Tunnel adapter isatap.{70D5B1BF-BEE1-475B-9752-73772D3EA37A}:
   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :

Tunnel adapter Teredo Tunneling Pseudo-Interface:
   Connection-specific DNS Suffix  . :
   IPv6 Address. . . . . . . . . . . : 2001:0:5ef5:79fb:2c33:3c3f:3f57:fff4
   Link-local IPv6 Address . . . . . : fe80::2c33:3c3f:3f57:fff4%2
   Default Gateway . . . . . . . . . : ::


With this kind of set up I usually go for the range 10.0.0.X
Setting the IP for the computer to 10.0.0.100 and then the Pi's use IP addresses from there up.


\Setting IP address on Windows Computer

Go to the Setting and select [Network and Internet]


Then select Ethernet and [Change adapter settings]







Right Click on the Ethernet adapter and select [Properties]



If you're not logged in as Administrator rights then you'll be asked to enter your Administrator password.

Once done select Internet Protocol Version 4 (TCP/IPv4) and click [Properties]


By default it's probably set to Obtain IP address automatically with the same for DNS

Click [Use the following IP address:] and enter the IP address you wish to use on the computer.
As I mentioned I set  mine to 10.0.0.100

When you click OK it might say a subnet isn't set and set a default of 255.0.0.0.  Just accept the subnet.  It is used to keep IP addresses in organised groups so it doesn't matter what it is for our purposes as long as our 2 IP addresses are included which they will be.



The just click OK and close all the windows that have been opened.  All is set now for the computer.

For the Pi side  you ill either need a monitor, keyboard and mouse or to have a router to connect the Ethernet that way or have wifi setup as this method uses the GUI desktop tool. 


I'm using RealVNC as have been playing with Minecraft over VNC
Connect using RealVNC to your wifi or DNS provided IP address for your Ethernet port.

Top right in the task bar right click on the network/wifi indicator and select [Wifi network (dhcpcdui) Settings]



This will open the Network Setting tool

It opens with the Configure: Interface option but with nothing selected. In the blank drop down select eth0

Automatically configure empty options should be ticked with all fields empty.
Not type the IP address you want to use in the IP Address: box.  For this one I used 10.0.0.102

Then [Apply] and [Close]

At this point I usually restart the Raspberry Pi and connect the Ethernet port directly to the laptop.
Of course my VNC session will disconnect. So I will have to connect again.

Now if I run ipconfig on the laptop I get the following where the Ethernet IP is 10.0.0.100 (result)

Ethernet adapter Ethernet:
   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::b0ac:5dbe:415b:e7e3%11
   IPv4 Address. . . . . . . . . . . : 10.0.0.100
   Subnet Mask . . . . . . . . . . . : 255.0.0.0
   Default Gateway . . . . . . . . . :

Wireless LAN adapter Wi-Fi:
   Connection-specific DNS Suffix  . :
   Link-local IPv6 Address . . . . . : fe80::501b:b10b:e1c4:62ff%5
   IPv4 Address. . . . . . . . . . . : 192.168.0.11
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 192.168.0.1


Reconnect RealVNC with 10.0.0.102 as the Raspberry Pi IP address and everything should work.
Now no need for a router, or a wifi. But if you have wifi then the computer and Pi can still connect to the Internet using wifi while maintaining their direct connection over the Ethernet so wget and other updates can still be done.

The great thing with this is also that since each Pis Ethernet connection will be on a different network if you have 10 laptops with 10 Pis you can do this setup on one Pi and then dd the microSDs on to the others and they will all work with no conflict.




Minecraft running over RealVNC from Raspberry Pi 3

Back at the PiParty in March RealVNC showed Minecraft running over VNC.  This doesn't seem like much of an achievement until you realise that Minecraft doesn't use X. It writes directly to the framebuffer, so for normal VNC Minecraft just comes up as black window.

I posted a short video from the party.  They had multiple sessions running on the one display.



Last wee RealVNC released the public Alpha of the new RealVNC server that enable Minecraft to run over VNC.

https://github.com/RealVNC/raspi-preview

I got a chance to install it today on a Pi3 and connect froma fairly low power laptop that cost £110.
Acer ES1-131 Celeron N3050 1.6GHz with 2GB RAM running Windows 10.

Firt run it went well, a little bit laggy (not sure if that's a real word).  I assumed it was because running over wifi.
Then I read the raspi-preview page again and noted there are a few optimisations available.

With the optimisation completed it ran really well.  Below is a short (sliglty out of focus) video of it running.



Now I'm looking forward to seeing the finals release of RealVNC.