Entries by Robert Rath

In these examples we will expand the entire disk from 32GB to 64GB.

The examples given are with and without an existing swap volume and will use an Ubuntu Live CD ISO as the surrogate.

Shutdown the target machine.

In VMware Player, select the target and go to 'Edit virtual machine settings'.

Select the 'Hard Disk' and then go to 'Utilities -> Expand...'.

Enter the new size, ie 32GB and click on 'Expand'.

Select the 'CD/DVD', ensure 'Connect at power on' is checked, select 'Use ISO image file:' and browse for an approriate Live CD ISO file to boot from. Click OK.

In VMware Player, select the target and start it. Ensure you are booting into the Live CD.

If the boot is incorrect, append the line 'bios.forceSetupOnce = "TRUE"' to your target 'vmx' file, make the necessary bios changes and then boot into the Live CD.

Make sure you select 'Try Ubuntu' and NOT install.

root@ubuntu:~# lsblk

Now that we have identified sda as our target we can go to work on it. Proceed with caution as you can easily destroy all your data!

fdisk /dev/sda # open sda in 'fdisk'

Use the 'p' command to print the current partition table, note the start sector addresses of both sda2 and sda5.

Use the 'd' command to delete partitions 5 and then 2.

Use the 'n' command to create a new extended partition 2. Use the default sector start address which may be less than the original sda2.

Use the 'n' command to create a new logical partition 5. Make sure the sector start address is exactly the same as the original sda5. Do not remove the LUKS signature if asked.

Use the 'w' command to write the changes and exit from 'fdisk'.

The system may automatically mount sda1/sda5 during operations. If so unmount them.

Simple Single Volume

In this example we will expand the entire disk from 32GB to 64GB.

cryptsetup luksOpen /dev/sda5 target    # use the LUKS password to decrypt sda5

vgscan --mknodes && vgchange -ay        # Identify and activate the LVM.

cryptsetup resize target                # Resize the crypt

pvresize /dev/mapper/target             # Resize the volume group

pvchange -x y /dev/mapper/target        # unlock the (LVM) physical volume.

lvresize -r -L+32G /dev/xubuntu-vg/root # increase our root volume by in this case 32GB, resizing (-r) the underlying filesystem 

vgdisplay                               # find out how much space is now available in our volume group

pvchange -x n /dev/mapper/target        # re-lock the physical volume

shutdown -h now                         # we are done with the Live CD so.

Include A Swap File

In this example we will expand the entire disk from 32GB to 64GB moving an existing swap file of 4GB to the end of the drive.

cryptsetup luksOpen /dev/sda5 target                         # use the LUKS password to decrypt sda5

                                                             # the system may automatically mount sda and the logical volumes

                                                             # inside target_encrypted_volume. If so unmount them.

vgscan --mknodes && vgchange -ay                             # Identify and activate the LVM.

cryptsetup resize target                                     # Resize the crypt

pvresize /dev/mapper/target                                  # Resize the volume group

lvdisplay                                                    # Use 'lvdisplay' to identify the target volumes for managing

lvremove /dev/xubuntu-vg/swap                                # remove our swap volume, it is in the way.

pvchange -x y /dev/mapper/target                             # unlock the (LVM) physical volume.

lvresize -r -L+32G /dev/xubuntu-vg/root                      # increase our root volume by in this case 32GB, resizing (-r) the underlying filesystem 

vgdisplay                                                    # find out how much space is now available in our volume group

lvcreate --extents 1024 -n /dev/xubuntu-vg/swap   xubuntu-vg # Create a new volume (516 comes from finding the available 'logical extents' in the group using 'vgdisplay'). Remove Swap signature

pvchange -x n /dev/mapper/target                             # re-lock the physical volume (may be redundant) 

mkswap /dev/xubuntu-vg/swap                                  # make the new 4GB volume a swap volume. Copy the UUID to the clipboard. 

lvdisplay                                                    # Use 'lvdisplay' to check our new volumes look good. 

lsblk                                                        # final sanity check 

shutdown -h now                                              # we are done with the Live CD

Edit the target machine to disconnect the CDROM at startup.

Start the target machine and check all changes work as intended.

References Used

https://linux.die.net/man/8/lvcreate
http://www.systemadminihater.com/linux/split-a-lvm2-volume-group-into-two-or-more/
http://www.thegeekstuff.com/2010/08/how-to-create-lvm
https://linux.die.net/man/8/lvresize
http://tldp.org/HOWTO/LVM-HOWTO/removelv.html
https://help.ubuntu.com/community/ResizeEncryptedPartitions
http://askubuntu.com/questions/63594/mount-encrypted-volumes-from-command-line

I used the the following reference for this modification to the Mavic 2 however it does not work for a Windows user so here is my version.

https://www.thedroneu.com/blog/atti-mode-mavic-2-pro-hack-zoom/

1. Download and install DJI Assistant 2 v1.1.2

https://www.mavichelp.com/Mavic-2#SoftwareArchive
https://www.sekidorc.com/press/DJI_Assistant2_Installer_v1.1.2_20170527.zip

2. On Windows edit line 113 of "C:\Program Files (x86)\DJI Product\DJI Assistant 2\AppFiles\main.js" to uncomment the line
mainWindow.webContents.openDevTools()

3. Open DJI Assistant 2 (do no open DJI Assistant 2 for Mavic if you also have a later version installed)

4. Referencing the instructions at https://www.thedroneu.com/blog/atti-mode-mavic-2-pro-hack-zoom/ make the following modification to 'fswitch_selection_2|g_config_control_control_mode[2] from 7 to 3.

Default configuration

fswitch_selection|g_config_control_control_mode[0] 12 = Tripod Mode
fswitch_selection_1|g_config_control_control_mode[1] 8 = Positioning Mode
fswitch_selection_2|g_config_control_control_mode[2] 7 = Sports Mode

Note we have modified the third switch position which was Sport mode (7) with ATTI mode (3)

Install Docker Engine - Community
=================================

ref: https://docs.docker.com/install/linux/docker-ce/ubuntu/
ref: https://docs.docker.com/install/linux/linux-postinstall/

$ sudo apt-get update # update the apt package index:
$ sudo apt-get install apt-transport-https ca-certificates curl gnupg-agent # install packages to allow apt to use a repository over HTTPS:
$ sudo apt-get install software-properties-common # install packages to allow apt to use a repository over HTTPS:
$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - # add Docker’s official GPG key:
$ sudo apt-key fingerprint 0EBFCD88 # verify that you now have the key with the fingerprint ...
$ sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" # set up the stable repository
$ sudo apt-get update # update/refresh the apt package index:
$ sudo apt-get install docker-ce docker-ce-cli containerd.io # install the latest version of Docker Engine
$ sudo docker run hello-world # verify the Docker Engine installation
$ sudo groupadd docker # create the docker group if not already present
$ sudo usermod -aG docker $USER # add your user to the docker group
$ newgrp docker # activate the changes to groups:
$ docker run hello-world # verify the Docker Engine installation without sudo
$ sudo systemctl enable docker # configure Docker to start on boot

These are a jumbled set of notes as I worked my way through downloading and building the Pi linux kernel from source code.

References

#ref: http://blog.eihis.com/?p=423
#ref: http://simonthepiman.com/how_to_setup_windows_file_server.php
#ref: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=66&t=57401
#ref: http://elinux.org/RPi_Kernel_Compilation#Get_the_kernel_source

On Pi

apt-get update
apt-get dist-upgrade
apt-get install build-essential
apt-get install module-assistant
m-a prepare
wget http://blog.eihis.com/wp-content/uploads/2013/07/linux-headers-3611_3611-2_armhf.deb
dpkg -i http://blog.eihis.com/wp-content/uploads/2013/07/linux-headers-3611_3611-2_armhf.deb
ln -s /usr/src/linux-headers-3.6.11+ /lib/modules/3.6.11+/src
ln -s /usr/src/linux-headers-3.6.11+ /lib/modules/3.6.11+/build
apt-get install samba
apt-get install samba-common-bin
m-a prepare

On Ubuntu

git clone -b rpi-3.10.y https://github.com/raspberrypi/linux.git
cd linux
git checkout master
git checkout rpi-3.6.y
export KERNEL_SRC=/home/robert/raspberry-pi/src/linux/
cd /home/robert/raspberry-pi/
git clone https://github.com/raspberrypi/tools
export CCPREFIX=/home/robert/raspberry-pi/tools/arm-bcm2708/arm-bcm2708-linux-gnueabi/bin/arm-bcm2708-linux-gnueabi-
cd /home/robert/raspberry-pi/src/linux/
make mrproper
scp root@192.168.10.31:/proc/config.gz ./
gunzip config
mv config .config
make ARCH=arm CROSS_COMPILE=${CCPREFIX} oldconfig
make ARCH=arm CROSS_COMPILE=${CCPREFIX} menuconfig
export MODULES_TEMP=/home/robert/raspberry-pi/modules/
make ARCH=arm CROSS_COMPILE=${CCPREFIX} INSTALL_MOD_PATH=${MODULES_TEMP} modules_install
cd /home/robert/raspberry-pi/tools/mkimage
./imagetool-uncompressed.py ${KERNEL_SRC}/arch/arm/boot/zImage
cd /home/robert/raspberry-pi/modules/lib/
tar -czvpf firmware+modules.tar.gz ./firmware ./modules
scp firmware+modules.tar.gz root@192.168.10.31:/lib/

On Pi

cd /boot
mv kernel.img kernel_original.img
mv fixup.dat fixup_original.dat
mv start.elf start_original.elf
mv bootcode.bin bootcode_original.bin
cd /opt
tar -czvpf vc_original.tar.gz ./vc
rm -fR vc
cd /lib
tar -czvpf firmware+modules_original.tar.gz ./firmware ./modules
tar -xzvpf firmware+modules.tar.gz

On Host

cd /home/robert/raspberry-pi/
git clone https://github.com/raspberrypi/firmware
cd /home/robert/raspberry-pi/firmware
git checkout next # d4f5315cfac4e was current on my pi before being overwrit
cd /home/robert/raspberry-pi/firmware/boot
scp bootcode.bin fixup.dat start.elf root@192.168.10.31:/boot/

cd /home/robert/raspberry-pi/tools/mkimage
scp kernel.img root@192.168.10.31:/boot/
${CCPREFIX}gcc -v 2>&1 | grep hard # check for hard float, even though came back as soft it looks like the board need hard!
cd /home/robert/raspberry-pi/firmware/hardfp/opt
tar -czvpf vc-hard.tar.gz ./vc
scp vc-hard.tar.gz root@192.168.10.31:/opt/

On Pi

cd /opt
tar -xzvpf vc-hard.tag.gz

Update

# I packaged up the linux kernel source and moved them to the pi and compiled locally

On Host

cd /home/robert/raspberry-pi/src
tar -czvpf linux.tar.gz ./linux
mkdir tmp
cd tmp
tar -xzvpf ../linux.tar.gz
cd linux
make mrproper
rm -fR ./.git
rm ./.gitignore
cd ..
tar -czvpf linux.tar.gz ./linux
scp linux.tar.gz root@192.168.10.31:/usr/src/

On Pi

cd /usr/src
rm linux
tar -xzvpf ../linux.tar.gz
cd linux
cp /proc/config.gz .config.gz
gunzip .config.gz
apt-get install ncurses-dev
make oldconfig
make menuconfig
make # commenced at 12:52 (13:10 for cross host)

... Robert

I have not done any work on this for some months now so am eager to pick it up again.

My thinking for this project has changed as I have worked out that using the Pi to directly control the active appliance peripherals will not work for two reasons.

a) There are no native analog inputs which are required for temperature measurements, and
b) There is a need to maintain fail-safe interlock protections and I do not trust the RaspberryPi/Linux platform to operate at the level of unbroken reliability required.

I have researched and sourced a small Atmel based Arduino board which will virtually drop into the main control PCB as a replacement for the existing OTP micro-controller. I plan to program this device to emulate the existing program or pass control over to the RaspberryPi but still take back control in the event the RaspberryPi application were to fail or attempt to do anything unsafe.

A simple serial interface back to the Pi (possible optically coupled for main isolation).

This gives me the best of all solutions, a fail-safe local controller which will work independently of the Pi but also allow the Pi to take over operations in a safe and controlled manner.


... more to come.

I discovered an issue with the proxy server and the URL re-write rule used to access the RaspberryPi. This blog entry is testing the ability to externally comment. Thanks to Dan Johnson for taking the time to let me know there was an issue.

Getting back to my original idea of Raspberry Pi powering my coffee machine I started reverse engineering the sensors in investigating the required inputs and outputs.

This image shows the main control board removed from its normal location and placed connected with inputs and outputs accessible.



One thing I quickly noted was that the entire ELV (Extra Low Voltage) circuit was references to the mains active supply line. This required just a little bit of care in making any measurements.

Measurements with a multimeter are generally not a problem as they are generally very well insulated but I need to use a DSO (Digital Storage Oscilloscope) for some of the measurements and my DSO was an earthed piece of equipment. I could have supplied the coffee machine using an isolation transformer but the heating cycle would overload it. Instead I chose to isolate the DSO and float it to mains active potential for all measurements. In this was I was able to determine the logical levels, thermistor resistor measurements against heating block temperature and the the flow-meter performance.

Flow Meter

The flow meter was found to deliver around 2140 pulses per litre unobstructed and 2368 working in the optimum pressure region. From this I note two points, a) that the flow meter is non linear and more testing will be needed to create an accurate count per litre to flow rate calibration, and b) the existing firmware uses flow-rate information as a proxy for pressure measurement in order to back off on the pump. The flow-meter input drives and interrupt pin on the micro'.

Temperature Metering

The temperature measurement is made using a 100K NTC device mounted on the heating block. Initial testing show the heating block is cycled for input voltages at the micro' of 2.31 (on) ans 2.12 (off) for a supply of 5.2V. From this I will be able to source the thermistor data assuming a block target temperature of 90degC.

Logic

The logic for the control of the pump, heater and discharge solenoid are simple outputs however all other logic comprises 6 multiplexed switch/led combinations where echo IO pin operate the LED and reads the input switch via multiplexing between input and output operations. See BES820XL.pdf for the full schematic details.

Power Supply

This is the first major issue to need an overhaul. The design uses a low cost capacitive supply and from a long experience in this kind of design I can only say that it needed to be replaced with a real supply if it would ever power the Raspberry Pi with WiFi.



I retained the 24VDC supply for the relay (for now), removed R4 and inserted a 5V 1000mA SMPS. That should be more than enough!



Here is the control board back into position for an extended period of trial in this configuration while I consider the next steps.




... Robert

I needed another Netsys 300N adapter for a different project. When I received it the form factor had changed so I decided to use the new smaller adapter for the 'Pi instead.



Here now with it's new profile is the 'Pi running all on it's own on the kitchen wall ( delivering this webpage! )



... Robert

I have been using my trusted Spyder3 Express in a WindowsXP environment for a few years now to calibrate my monitors and ensure consistent colour and tone rendering between computers. Recently however I upgraded to a new Windows7 dual monitor desktop and officially the Spyder3 Express no longer worked for me.

Looking for help on this issue I kept getting the same message that I need to pay double for the model which does support multiple monitors. The 'Express' is an inexpensive entry level product designed only to support a single monitor.

Rather than being forced to pay for an upmarket product with multiple monitor support I decided to find a work-around. Here is my successful solution providing monitor independent calibration for two monitors, an AOC and a BENQ. I apologize for this rather terse set of instructions. Feel free to ask questions if this does not work for you.

Step 1. - Get your dual monitor desktop configured and working the way you want.
Step 2. - Install the SpyderX Express drivers and software but do not begin any calibration.
Step 3. - Go into Screen Resolution settings (right click on the desktop) and change the display to only use monitor 1 as shown.

Step 4. - Perform a standard SpyderExpress calibration procedure on the selected monitor and confirm colour has been corrected as expected.
Step 5. - Using file explorer, navigate to the profiles directory 'C:\Windows\System32\spool\drivers\color'.
Step 6. - Locate the newly created file 'Spyder3Express.icm' and make a copy of it in the same directory, in my case 'Spyder3Express-AOC2236-20121005.icm'.
Step 7. - Repeat Steps 3-5 as above but this time select monitor 2 as shown below and calibrate it in the same way.

Step 8. - Locate the new 'Spyder3Express.icm' file for the second monitor and make a copy of it in the same directory, in my case 'Spyder3Express-FP222W-20121005.icm'.

The next part is a little tricky and may be dependent on the menus in your graphics setup.

Step 9. - Go into Screen Resolution settings (right click on the desktop), click on 'Advanced settings', select the 'Color Management' tab and click on the 'Color Management...' option.
Step 10. - Select the 'Device:' monitor 1 and make sure the check box 'Use my settings for this device' is selected.
Step 11. - Click 'Add..' and navigate through the list of profiles to find the profile you created for monitor 1 using the 'File name', not the profile 'Name'.
Step 12. - With the new profile for monitor 1 now in the profiles list, 'Set as Default Profile'.
Step 13. - Repeat Steps 9-12 for monitor 2 and confirm setting are similar to those shown below.


Step 14. - Exit the graphics menus and confirm the new independent calibrations can be enabled and disable using the SpyderExpress system tray tool.

Yes it's a little messy but you really do not need the more expensive multiple monitor version. The 'Express' will do multiples just fine.

... Robert

Prior to attempting to run my 'Pi at 1000Mhz I decided it would be a good idea to backup the entire machine.

As it uses a 4GB SD it made sense to use another 4GB card as the backup destination. As it turns out it was simpler than I expected.

I placed a new 4GB SD card in a USB card reader and inserted into on of the 'Pi's USB ports. I then checked to see what device node the 'Pi used for the card. In my case I found the card at '/dev/sda', and that it has not been automatically mounted. In my case it was not automatically mount but other/future version of 'wheezy' may do this so it is important to use the 'mount' command to check this.

The following command line shows how I block copied the entire content on the operating system block device '/dev/mmcblk0' to the unmount SD card at '/dev/sda'.

sudo dd if=/dev/mmcblk0 of=/dev/sda bs=4M

root@raspberrypi:/boot# dd if=/dev/mmcblk0 of=/dev/sda bs=4M
945+1 records in
945+1 records out
3965190144 bytes (4.0 GB) copied, 840.205 s, 4.7 MB/s

To test I simply placed the new card into the Raspberry Pi and up it came, a perfect clone!

As it turns out, my 'Pi failed to start at 1000Mhz so the effort was well worth it .


... Robert

Today I discovered my Pi had gone off-line! No WEB, no SSH. I am not sure what happened but a reboot brought it back to life again.

So while it had my attention I decided a few tweaks were in order.

Tweak 1. More RAM

During general operations I had previously noticed MySQL had grabbed a substantial chunk of virtual memory and on a NAND based system this is not desirable. I am not sure how the memory was being used but seeing I am not using HDMI video I could reconfigure the Pi to use less video memory and give more back to user space applications.

In my case I copied '/boot/arm240_start.elf' to '/start.elf' which immediately gave me back a much needed extra 48M of RAM.

Tweak 2. Bump Up The Speed

I edited the '/boot/config.txt' file to enable CPU overclocking beginning at 800Mhz initially to see how that goes.

#uncomment to overclock the arm. 700 MHz is the default.
arm_freq=800

I like the raspberry coloured gear graphics I found so I may use this for all general configuration tweaking posts.


... Robert

Added tightvnc for headless GUI.

http://www.penguintutor.com/linux/tightvnc

... Robert

It would be a shame to lose everything I have put into the Raspberry Pi blog so it's time to put in a backup regime.



Strategy

The Raspberry Pi blog is located both both '/var/www/raspberrypi/' and in the serendipity-db catalog of the local MySQL database. We will need to backup up both to completely cover ourselves.

The strategy for backup will be to make archives of both the filesystem and the mysql database, archive them together and then copy to the network drive under a unique filename. The backup will be run from a script which which will live in the '/var/www' directory and be regularly run from an entry in the '/etc/crontab' file.

During the backup process I will create temporary files on the network drive to avoid wear on the local SD card.

We first setup NFS or SAMBA networking and ensure we have mounted our network storage device at a suitable mount point. I have chosen NFS in this example. To use Windows networking adapt the instructions below accordingly.

1. Install NFS client (checked already installed as part of the Weezy distribution).
2. Make a mount point for backups at '/var/www/backup' and add edit '/etc/rc.local' to mount our external resource on boot by adding the following line 'mount -t nfs -o nolock [IP address or hostname of your NAS server]:/var/local/www /var/www/backup'


Backup Script

Here is my script. Note the use of the file '/var/www/backup/sync_www' to ensure we have mounted the network drive and are not just working with our local mount point.

#!/bin/sh

if [ -e /var/www/backup/sync_www ]; then

mkdir -p /var/www/backup/raspberrypi/
cd /var/www/
tar --exclude-vcs -czf ./backup/raspberrypi/raspberrypi-www_`date +%y_%m_%d`.gz raspberrypi && \
mysqldump -u YOUR_MYSQL_USERNAME_HERE -pYOUR_MYSQL_PASSWORD_HERE serendipity-db | gzip > ./backup/raspberrypi/raspberrypi-mysqldump_`date +%y_%m_%d`.gz && \
tar --remove -cf ./backup/raspberrypi/raspberrypi-blog_`date +%y_%m_%d`.tar ./backup/raspberrypi/raspberrypi-www_`date +%y_%m_%d`.gz ./backup/raspberrypi/raspberrypi-mysqldump_`date +%y_%m_%d`.gz

exit 0

else

exit 1

fi

A brief description pf the steps of the script are as follows

1. Check to see we have mounted the network drive by looking for a file called 'sync-www' which we have alread place on the network drive.
2. Create our target backup directory if it does not already exist.
3. Change to the '/var/www/' as our working directory.
4. Create a dated temporary archive of the files in '/var/www/raspberypi'
5. Create a dated temporary archive of the mysql data dumped from the catalog 'serendipity-db'
6. Create the final backup archive removing the temporary working files.


Handling Erorrs

Note the use of '&& \' after each line ensures that the next line only executes if the previous command was successful otherwise the script exits with error code 1.

Note this script could be further enhanced with email notifications of success or failure as needed.


Scheduling

Finally the following entry in '/etc/crontab' will ensure this script runs daily at 2:30 am.

'30 2 * root /var/www/backup-www.sh &'

... Robert

Putting the Raspberry Pi into an appliance means that it will not have access to an Ethernet connection and will require USB WiFi.

Which USB Wifi Device?

Adding USB WiFi to a Linux device is generally quite easy however there are limitations which apply to non PC (non x86) applications such as the ARM11 based Raspberry Pi.

The chipset in the WiFi device selected for the Raspberry Pi must be one already supported for the ARM11 device. Simply relying on a chipset vendor to claim Linux support is not enough as this may really mean PC based x86 Linux only. True Linux support means the chipset vendor has made driver source code available to be built for any target CPU.

Two of the best supported chipset vendors are Ralink and Realtek. For my application I have used the 'Netsys Wireless N Model: NET300N' based on the Realtek 8191SU chipset which already as Raspberry Pi driver support using the Realtek r8712u driver.

This USB WiFi device is available from http://dealextreme.com for about $10.

Making It Work

The following two resources provided the general guidelines I used to get the WiFi up and running in my network.

http://mitchtech.net/realtek-wireless-dongle-rt3070-on-the-raspberry-pi/
http://ubuntuforums.org/showthread.php?t=571188

I installed 'lshw' ( apt-get install lshw ) which provides diagnostic information about hardware drivers however as this installation went so smoothly I am not sure this was absolutely necessary.

root@raspberrypi:~# lshw -C network
-network:0
description: Wireless interface
physical id: 1
bus info: usb@1:1.2
logical name: wlan0
serial: 00:0f:11:66:16:d0
capabilities: ethernet physical wireless
configuration: broadcast=yes driver=r8712u multicast=yes wireless=unassociated
-network:1
description: Ethernet interface
physical id: 2
logical name: eth0
serial: b8:27:eb:45:84:2e
size: 100Mbit/s
capacity: 100Mbit/s
capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=smsc95xx driverversion=22-Aug-2005 duplex=full firmware=smsc95xx USB 2.0 Ethernet ip=192.168.10.31 link=yes multicast=yes port=MII speed=100Mbit/s

After manually confirming the following command lines brought up my network,

ifconfig wlan0 down
dhclient -r wlan0
ifconfig wlan0 up
iwconfig wlan0 essid "MYESSID"
iwconfig wlan0 key MYKEY
iwconfig wlan0 mode Managed
dhclient

I then copied thew into '/etc/rc.local' so that the WiFi network would be brought up on boot. An important point for me was that the web article suggests adding the line 'ifconfig eth0 down' to the '/etc/rc.local' file but this would mean that hardwired ethernet would be shutdown and not available should it be needed in an emergency.

The final changes I need to make were to my DHCP server and router configuration so that the 'Pi' always gets a fixed IP address assigned for correct virtual server port forwarding.

Next Steps

You might notice the nice plastic case (from Element14) in the image which will protect the 'Pi' from and ongoing development accidents!
I will now run this setup for a while and look for general stability as a WiFi based web host.

...Robert

What do you get if you cross a Raspberry Pi with a Breville 820ES Espresso machine? A Raspberry Latte!

There has been a long standing symbiotic relationship between engineers and coffee!! So it only seems natural that a candidate project for my espresso machine is a Raspberry Pi brain transplant. Of course I'll keep the blog on the coffee machine, it seems appropriate!

I see the project running something like this.

1. Acquire the circuit diagram and study to understand issues such aspower supplies and interfaces.
2. Reverse engineer the control processes currently operating on the espresso machine.
3. Design a suitable interface.
4. Implement WiFi on the Raspberry Pi to avoid running cat5 to the coffee machine.
5. Develop a suitable coffee machine application.
6. Develop a suitable web based interactive application

Some issues I see.

1. Failure mode safety management (circuit design).
2. Electrical isolation between the Raspberry Pi and the high voltage electrical devices.
3. Physical space and form factor.
4. Being without coffee during key development steps, ie keeping the coffee flowing during modifications.

... Robert

BES820XL.pdf