Recently, I have been spending time looking at the Swagger 2.0 Specification. There XML representation and Enumerations are tricky. Here is an example of a Swagger Enumeration in YAML.
You can test the YAML at http://petstore.swagger.io/#!/default/get_demo
I am plugging away working with my Pi. I went back to the Ada Fruit Site, and started working on one of the tutorials from the part I purchased – https://www.adafruit.com/products/2125 I want to be able to demonstrate a simple wiring with my Pi works.
I selected Email Notifier. I read through it, and realized I needed to convert it to work for the B+ model. The pi4j website has a nice diagram for the pins http://pi4j.com/images/j8header-b-plus-large.png and I simplified the test a bit.
I launched the simple python file
pi@seconds ~ $ sudo python testPi.py
I added the pi4j dependency to my maven pom
<dependency> <groupId>com.pi4j</groupId> <artifactId>pi4j-core</artifactId> <version>1.0</version> </dependency>
I create a servlet which replicated the same code from before (GPIO).
I copied the war file to the local webapp directory, and restarted jetty
pi@seconds /opt/jetty/web/bbq/webapps $ sudo cp ~/pi.webapp.war ./ pi@seconds /opt/jetty/web/bbq/webapps $ sudo chown jetty:jetty pi.webapp.war pi@seconds /opt/jetty/web/bbq/webapps $ sudo /etc/init.d/jetty restart
Refer to https://wiki.eclipse.org/Jetty/Howto/Deploy_Web_Applications and I did have to add –module=jsp to the start.ini for my web configuration.
I hit the servlet – http://192.168.1.200/pi.webapp/Control?status=true
Which makes sense, since “Software using the Pi4J library must be run with ROOT level permissions.” (actually it doesn’t since I am running as root)…
Issues remain. I’ll tackle them on a different day 🙂 … Part 5 …
The Raspberry Pi is a device that has so many options open: You can extend the hardware. You can extend the software. I choose to tackle extending the software to start, so I can get the experience that I want setup, and running on the device. The experience I am after is the web interface to control my Raspberry Pi.
For a Java developer, I conclude that a lightweight interface hosted on a Jetty server is probably easiest. The Jetty server is a 12.9M download and 30M expanded. It’s also used frequently in devices, and why reinvent the wheel, use the approach that Industry is using. Jetty is designed for a small memory footprint. (I did consider using Tomcat Embedded, and came to the conclusion I’d probably want to many features.)
I downloaded the Jetty archive to my local user’s directory. Note, since I want to just use jetty.zip I’m renaming the output file with wget -O.
wget -O jetty.zip http://download.eclipse.org/jetty/stable-9/dist/jetty-distribution-9.2.10.v20150310.zip
I make a directory for the application server, and move over jetty.zip to that directory.
sudo mkdir -p /opt/jetty sudo mv jetty.zip /opt/jetty
Next I launched into the sudoers root shell, and extract the Jetty archive. I decided to move it into the runtime folder, so I can have an easy place to backup from. (Remove the extra space from the .zip)
sudo -s cd /opt/jetty unzip jetty.zip mv jetty-distribution-9.2.10.v20150310/ runtime rm jetty.zip
Next, I wanted to setup Jetty as a service, and check that Jetty starts
cp runtime/bin/jetty.sh /etc/init.d/jetty echo JETTY_HOME=`pwd`/runtime > /etc/default/jetty service jetty start Starting Jetty: . . . OK Sun Apr 12 15:38:40 UTC 2015 service jetty stop Stopping Jetty: OK
Next, I want to automatically start Jetty with the right runlevels
update-rc.d jetty defaults
I want to configure Jetty to run with a set user jetty.
mkdir -p /opt/jetty/web/bbq mkdir -p /opt/jetty/temp useradd --user-group --shell /bin/false --home-dir /opt/jetty/temp jetty
There is a base configuration that needs to be setup the base site.
cd /opt/jetty/web/bbq java -jar /opt/jetty/runtime/start.jar --add-to-start=deploy,http,logging
Next, edit the default port value.
vi start.ini ## HTTP port to listen on jetty.port=80
Finally, I wrap the configuration of the jetty service and app.
chown -R jetty:jetty /opt/jetty echo "JETTY_HOME=/opt/jetty/runtime" > /etc/default/jetty echo "JETTY_BASE=/opt/jetty/web/bbq" >> /etc/default/jetty echo "TMPDIR=/opt/jetty/temp" >> /etc/default/jetty
A good check is to look at service jetty status, and confirm the settings, and then restart your Raspberry Pi. I did find that the startup time was significantly effected by the additional service. ( +25 seconds from the original 15)
Navigate to http://192.168.1.200/ (or whatever IP you have used) and confirm the page loads Jetty. If you see a 404, you’re off and ready for the next phase. (as am I) 🙂
I don’t know how I did it. I lost wireless connectivity, so I was forced to plugin my Raspberry Pi to the Lan. Once, plugged in I could find it via the DHCP table on my router.
I first checked the iwlist wlan0 scan to see if my home network was listed. The home network was listed. It was.
I checked the wpa_supplicant configuration ~ $ sudo vi /etc/wpa_supplicant/wpa_supplicant.conf and confirmed it pointed to the right network. I also checked dmesg to see if there were any hints for wpa_supplicant.
I looked at the /etc/network/interfaces and found
iface wlan0 inet manual
which I converted to
iface wlan0 inet dhcp
Also wpa-debug-level 3 was very helpful and must proceed the wpa-roam statement in the interfaces.
Also running the wpa_supplicant command can result in some good details
pi@seconds ~ $ sudo wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf
I also found this link helpful. https://wiki.debian.org/WiFi/HowToUse It showed how to reset manual to dhcp in the /etc/network/interfaces file
Finally, I used http://weworkweplay.com/play/automatically-connect-a-raspberry-pi-to-a-wifi-network/ to finally review, and finally I broke down and set a static ip. Not sure why it won’t automatically take a dhcp configuration.
In recent weeks, I haven’t revisited the Raspberry Pi – Running, Vacation, Work have conspired to keep me away from hobby project.
I’ve stared at the parts long enough, and decide to plug the Raspberry Pi base into the wired network. I plugged in the Raspberry Pi into the Power outlet, and I got the Red Light. I logged into my router to see if the Pi picked up the Raspberry Pi, and I found the IP from my routers IP reservations table. I was able to SSH into the Pi and quickly check the release version ( cat issue ) – Raspbian GNU/Linux 7 \n \l.
I turned on the SSH server using sudo raspi-config and the advanced options.
The first thing I thought – Upgrade / Update to get the latest environment for the Raspberry Pi. It’s a good start – always good to be up-to-date. Per the documentation, it may be necessary to run – sudo apt-get clean.
sudo apt-get upgrade
sudo apt-get updateThe raspi-config is another item that may need to be updated. The update goes out and queries for the latest raspi-config, installs and relaunches the raspi-config.
sudo raspi-config
Select Option 8 - Advanced Options
Selection Option A0 - Update
Select Yes
Next, I looked updated the Java version. From reading the documentation, the next versions of the Pi are going to automatically include the Java installs.
sudo apt-get update && sudo apt-get install oracle-java7-jdk
I grabbed the Pi4J project jar files. The Pi4J is an opensource project which has some great details on PINOUT and boilerplate java code to access the underlying pin readouts. I ran some quick code to get the latest snapshot installed.
wget http://get.pi4j.com/download/pi4j-1.1-SNAPSHOT.deb sudo dpkg -i pi4j-1.1-SNAPSHOT.deb
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Pi4J is also installed on the Sonatype repositories and developed on GitHub. Pi4J includes a script for managing updates. It’s very convenient with the Apache 2.0 License.
I was ready run a sample program – Get Sample, Compile and Run.
wget https://raw.githubusercontent.com/Pi4J/pi4j/master/pi4j-example/src/main/java/ListenGpioExample.java pi4j ListenGpioExample.java pi4j -run ListenGpioExample
Eventually, I am going to get to the point where I use the diagram from Pi4j. The future efforts are going to take some time to get to – This step was the right step in the direction I want to go. BBQ Champion.
Thanks To Ada Fruit I picked up a first version Raspberry Pi B+. The experience brings me back to building my first computer and modifying it.
I picked up an B+ Kit from Ada Fruit (based on the fact they have awesome tutorials). I also picked up a Motor Controller, a Bread Board to hook up peripherals, and a Touch Screen Display. The touch screen display wasn’t actually compatible with the kit I purchased. Lesson learned – check the Male and Female connectors for the Displays and PIN (IN/OUT) counts.
I laid out all the components on the bubble wrap, and I started assembling the components into one computer. The experience was rather like assembling a jigsaw puzzle.
I used the 4G microSD card that came with the B+ kit. I used it to immediately configure Debian and setup SSH. I got it on the wireless using the USB dongle for wireless, and I ran the updates for aptitude update and aptitude full-upgrade. It’s nice that it persists all these changes.
Now, that I am on the wireless, I can unplug the Raspberry Pi from the monitor, and connect to it via SSH. It’s fantastic stuff. I am now going to work on my motor controller.
I have been working IBM Integration Broker 10.0.0.4. I found it hard to find concise documentation on setting up/creating a new provider
mqsicreateconfigurableservice TESTNODE_cheetah -c JDBCProviders \
-o DB2Two -n connectionUrlFormat -v \
"jdbc:db2://[serverName]:[portNumber]/[databaseName]:user=[user];password=[password];"
mqsisetdbparms TESTNODE_cheetah -n jdbc::employeeIdentity -u db2admin -p passw0rd1940!
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n securityIdentity -v employeeIdentity
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n portNumber -v 50000
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n serverName -v 9.32.18.166
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n databaseType -v DB2
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n databaseName -v SAMPLE
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n jarsURL -v c:\db2jars
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n type4DatasourceClassName -v com.ibm.db2.jcc.DB2XADataSource
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n type4DriverClassName -v com.ibm.db2.jcc.DB2Driver
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n databaseVersion -v 10.1
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n environmentParms -v ""
mqsichangeproperties TESTNODE_cheetah -c JDBCProviders -o DB2Two -n jdbcProviderXASupport -v true
Restart the Integration Server
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