3rd Milton Keynes Raspberry Jam

Fewer people this time at the Milton Keynes Raspberry Jam, which we decided was mostly due to this being most school’s half term (one week holiday, for those not in the UK). However, it was a very busy couple of hours. Lots of projects were shown, including my PiPodCorder.

Other projects which we saw were:

  • Ken Thompson’s work on a museum front-of-house display using hist TBOPlayer.
  • Daniel Bull’s work-in-progress on his Super 8 videocamera.
  • Daniel Bull’s actual working home heating regulator.
  • A work-in-progress on a project to develop a robot hand to operate front-panel computers at the National Museum of Computing.
  • Peter Onion’s work on the Elliott 603 emulator (buzzing and whistling away in the background, it was, reading virtual paper-tape).
  • A quite wonderful project. The first internet-enabled Enigma coding machine. Just fantastic.

Peter also treated us to a mini-masterclass in soldering – how to do it, how not to do it and how not to destroy anything in the process. I’ll post a video here or over at Raspi.tv of the mini-course.

Suffice to say, those of us who watched the class got a lot out of it and I fully expect all of us to have soldered something new by the end of the week!

The next Jam will be in November, then Peter’s planning to skip December and hold one in early January and one in late January to make up for it.

Met a few new people at the Jam, including a family from Stevenage who are going to use the Pi during half term for both hardware and software projects.

Also in attendance was David Taylor from Cyntech who have recently started to develop a series of products for the Raspberry Pi including a very fashionable new case. The case is a much snugger fit than the ModMyPi cases and includes a slit on the side for the GPIO cable. We were also given hints at a few of their upcoming products which show that these guys are really thinking about the Pi community and how to support us.

 

Open source GPU userland (and opinion piece)

[Phoronix] Raspberry Pi GPU Driver Turns Out To Be Crap

Very out of my depth on this one, but here is the announcement from the Foundation. At first glance, it appears to be a huge step forward, but others have taken this as an opportunity to heap abuse and criticism on the Foundation. This article over at Phoronix: Raspberry Pi GPU Driver Turns Out To Be Crap sums it up and links to a couple of other articles. Apparently, the abuse has been quite shocking on Twitter.

I say we should be grateful the Foundation has released anything at all. I wouldn’t know what to do with it, but it sounds like a step forward even if it’s not the whole shebang as developers have been asking for.

[Phoronix] Raspberry Pi GPU Driver Turns Out To Be Crap

Once again, I think the only criticism that can be aimed at the Foundation is a lack of editorial control, especially with their headlines. There’s rather too much small print and information-on-the-side about this for my liking – apparently, Eben and Liz have been quite clear about what has actuallybeen released but the

[Phoronix] Raspberry Pi GPU Driver Turns Out To Be Crap

information is spread out far and wide. As always, responses to criticisms have been met with the usual sarcasm (“We don’t want you developing an ulcer” quips Liz) and snide remarks, and as always the complainers are expected to take these remarks and ignore them, lest they get banned, blocked or otherwise covered in hot lead.

[Phoronix] Raspberry Pi GPU Driver Turns Out To Be Crap

Lack of public relations skills aside, however, the Foundation has done a good thing here. If you can’t feel grateful, at least give them credit for moving things forward when they didn’t have to.

Set-up the Raspberry Pi as an access point

I’ve had a successful time getting the Pi set-up as a Wifi access point. The end result is an access point running on one wifi dongle, bridged to a second wifi dongle for an internet connection. This means that I can connect a phone to the Pi using an adhoc wireless network connection.

For the access point dongle,  I am using an old AzureWave AW-NU221 dongle. It’s an ugly white plastic thing that’s definitely NOT a ‘nano’ dongle. This dongle is known on my system as wlan3.
For the bridged wifi dongle, I’m using the good old reliable Edimax. This is known as wlan0.

Be aware that all my scripts are stored in /boot/redwing-pi and that I am logged in as root when I run it!

 

Here is a script to install everything you need and to walk you through the set-up.

#!/bin/bash
clear

echo "Redwing Access Point installer"
echo "(c) Michael Horne 2012 / Recantha"
echo "Please note all responses requested are Case Sensitive"
echo ""
echo "SPECIFY WIRELESS DEVICE"
# DEBUGGING MODE - set to something other than hostapd.conf
HOSTAPDFILE=hostapd.conf
# List devices
iwconfig 2>/dev/null | grep wlan
echo "Please type in the name of the wlan device to use as the access point"
read WLAN

echo "Type in the name of the wifi driver. This is normally nl80211 but may vary. You can always change this later by modifying the hostapd.conf file"
read DRIVER

echo "Type in the name of the access point you wish to create"
read SSID

echo "Type in the passphrase for the access point"
read PASSPHRASE

echo "PACKAGE INSTALLATION"
echo "There are a fair few packages that need to be installed. Some of these may require you to confirm their installation"
echo "Press any key"
read -n1 -s IGNORE

apt-get update
apt-get install hostapd
apt-get install dnsmasq
apt-get install dhcpd
apt-get install wireless-tools hostapd bridge-utils

echo ""
echo "Using $WLAN for the access point"
echo ""

# HOSTAPD SECTION
echo "Generating the hostapd.conf file"

# Create the hostapd.conf file
echo "" > $HOSTAPDFILE
echo "interface=$WLAN" >> $HOSTAPDFILE
echo "driver=$DRIVER" >> $HOSTAPDFILE
echo "ctrl_interface=/var/run/hostapd" >> $HOSTAPDFILE
echo "ctrl_interface_group=0" >> $HOSTAPDFILE
echo "ssid=$SSID" >> $HOSTAPDFILE
echo "hw_mode=g" >> $HOSTAPDFILE
echo "channel=10" >> $HOSTAPDFILE
echo "wpa=3" >> $HOSTAPDFILE
echo "wpa_passphrase=$PASSPHRASE" >> $HOSTAPDFILE
echo "wpa_key_mgmt=WPA-PSK" >> $HOSTAPDFILE
echo "wpa_pairwise=TKIP" >> $HOSTAPDFILE
echo "rsn_pairwise=CCMP" >> $HOSTAPDFILE
echo "beacon_int=100" >> $HOSTAPDFILE
echo "auth_algs=3" >> $HOSTAPDFILE
echo "wmm_enabled=1" >> $HOSTAPDFILE
echo "" >> $HOSTAPDFILE

echo ""
echo "Do you want to change the system so it uses the hostpad.conf file just generated? (Do this ONCE and ONCE only)"
read -n1 -s CONFIRM
if [ "$CONFIRM" == "Y" ];then
echo "DAEMON_CONF="/boot/redwing-pi/access_point/hostapd.conf"" >> /etc/default/hostapd
fi

echo "Do you want to route the IP tables for network forwarding? [Y to do it]"
read -n1 -s CONFIRM
if [ "$CONFIRM" == "Y" ];then
iptables -A FORWARD -i $WLAN -o wlan0 -s 10.0.0.0/24 -m state --state NEW -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A POSTROUTING -t nat -j MASQUERADE
sh -c "echo 1 > /proc/sys/net/ipv4/ip_forward"
fi

echo "Do you want to set /etc/network/interfaces for the access point (wlan3)? (Do this ONCE and only ONCE) [Y to do it]"
read -n1 -s CONFIRM
if [ "$CONFIRM" == "Y" ];then
echo "" >> /etc/network/interfaces
echo "auto $WLAN" >> /etc/network/interfaces
echo "iface $WLAN inet static" >> /etc/network/interfaces
echo " address 10.0.0.1" >> /etc/network/interfaces
echo " netmask 255.255.255.0" >> /etc/network/interfaces
echo " wireless-channel 10" >> /etc/network/interfaces
echo " wireless-ssid "$SSID"" >> /etc/network/interfaces
echo " wireless-mode ad-hoc" >> /etc/network/interfaces
echo "" >> /etc/network/interfaces

echo ""
echo "NB: If you have run this twice, you will need to remove the duplicate text"
echo "NB: If your wifi dongle for the access point is NOT on wlan3, edit /etc/network/interfaces to suit"
fi

# Sets dhcp range and length of lease
echo "MANUAL PROCESSES REQUIRED"
echo "Edit /etc/dnsmasq.conf"
echo "Find and change interface setting to : interface=$WLAN"
echo "dhcp-range=10.0.0.2,10.0.0.5,255.255.255.0,12h"
echo ""

You then need another script to actually run the access point:

#!/bin/bash
killall hostapd
clear

USAGE="Usage: start_access_point   "
if [ "$1" == "" ];then
	echo $USAGE
	exit 0
fi

if [ "$2" == "" ];then
	echo $USAGE
	exit 0
fi

if [ "$3" == "" ];then
	echo $USAGE
	exit 0
fi

WLAN=$1
ESSID=$2
BRIDGETO=$3

ifconfig $WLAN down
iwconfig $WLAN mode ad-hoc
ifconfig $WLAN up
iwconfig $WLAN essid "$ESSID"
ifconfig $WLAN inet 10.0.0.1

ifconfig $WLAN up 10.0.0.1 netmask 255.255.255.0
udhcpd $WLAN &

iptables --flush
iptables --table nat --flush
iptables --delete-chain
iptables --table nat --delete-chain
iptables --table nat --append POSTROUTING --out-interface $BRIDGETO -j MASQUERADE
iptables --append FORWARD --in-interface $WLAN -j ACCEPT
sysctl -w net.ipv4.ip_forward=1

# Now actually start hostapd
hostapd /boot/redwing-pi/access_point/hostapd.conf
#hostapd /boot/redwing-pi/access_point/hostapd.conf 1> /dev/null &

Now, I can’t guarantee that’ll all work, but it did for me!

 

Setting up LCD via GPIO on RasPi

I found these while reading my RSS feeds (If you click this link you’ll be able to subscribe to my feed that merges together over 100 different feeds into one).

These are great step-by-step articles from TechFruits, with circuit diagrams on how to get an LED breakout board working with the Pi. Wish I’d had these to work from when I did mine!

Read the articles here:

Setting up LCD via GPIO on RasPi – Part 2

Setting up LCD via GPIO on RasPi – Part 3.