Egham Raspberry Jam report for Sunday 20th January

Having caught Raspberry Pi fever and attending the excellent Milton Keynes Raspberry Jam on a couple of occasions I approached my employer about running a Raspberry Jam at our offices in Egham. After a bit of explaining what a Raspberry Pi is and what a Raspberry Jam is they gave the green light and we put the 20^th of January in the calendar as the date for the Raspberry Jam.

Eventbrite page was set up to allow registration to keep the numbers to a reasonable level and started to promote the event on the Raspberry Pi forum and on Twitter through my @Winkleink account. Through retweets from @Raspberry_Pi and @Teknoteacher we got 50 registrations with over a week to go.

I put out the call for presenters and two people stepped forward

Dave Ackerman the Pi in the Sky man offered to present on sending balloons into the stratosphere and using a Raspberry Pi transmitting live images from the flight.

Stephen Cornes offered to present on using a hard drive as your primary drive and also connecting to the Raspberry Pi over serial using the GPIO serial connection.

The 20th January rolled around and after snowing for 3 days I expected the day to be a flop.
Giving myself loads of time I got there for 12:30 with a 2:00 start and began getting things organised.

Then to my joy Dave arrived about 1:00 with 3 boxes of bits and a presentation so I knew it wasn't only going to be me.

We both got ourselves set. Dave in the boardroom with the projector and the theatre seating and me the main area where the show and tell activity was going to go on.

I’d spent the week getting a small cheap remote control car to be controlled through Scratch (see previous post) but due to my mad/bad wiring when I set it up interference between the wires meant the car always wanted to go left. I could show the wheels spinning forward and backwards but the grand plan of having people try to figure out how to program Scratch to get the car to navigate an obstacle course did not materialise.

Alongside my nearly working demo Dave set up his ballooning bits.

Paschal Egan showed using the GPIO to produce 433MHz home automation control signals to switch on and off domestic appliances.

Ian Law brought along his set up to see if someone could help with debugging the Python snake game he was working through from the Raspberry Pi Users Guide.

Robin Fordham set up his circuit that expanded the GPIO pins using I2C controls.

At the far end Leo White brought along his Raspberry Pied BigTraks with robotic arm and webcam.

In the end over 30 people made it out in the snow to attend. An amazing turnout considering the weather. Ranging in age from 15 to a much older.

Once most people had arrived Dave presented Pi in the Sky. I was so wrapped up I failed to keep him to time so we got a lot of details on what was involved.

Then Stephen presented on using a hard drive as your main file system and also connecting over GPIO using serial. His impetus for both was issues with SD cards giving errors and not wanting to have to attach the Raspberry Pi to a screen. If you connect over serial then you even get to see the boot sequence. This is not the case if you SSH in over the network as networking has to be active for the SSH connection to happen.

Stephen kept to time and by the rush of people to the front after he finished his presentation was of interest to a number of people attending.

After the presentations we went back to the show and tell area. Where we mingled and chatted. Those of us with demos answered questions and tried our best to explain what we did, how we did it, why we did and what use it was.

I must admit seeing the BigTraks with the robotic arm controlled by the PS3 controller over Bluetooth and live streaming to a browser was fantastic. It really showed the power of the Raspberry Pi and the number of things it can do at the same time.

There was a crowd around Ian’s Raspberry Pi trying to figure out what was wrong with his code. In the end Robin Fordham came to his rescue and worked out there was a rogue file in the directory with the program causing problems. Once this was deleted then everything worked as it should after a simple typo error was fixed.

From the feedback people have provided it sounds like the event was enjoyable and achieved its goal in inspiring people to do more. One person has invested in a Raspberry Pi, another purchased a Pi Cobbler and others found answers to their questions that would allow them to continue with their projects.

From my point of view as an organiser of a Raspberry Jam I must admit it was quite painless. Just set things up. Let people know it’s on. Manage registration on Eventbrite and then play host on the day.

A few things I would tweak are

Maybe have each person do a 10-20 second intro (name, own a Pi, what done so far, what do you wish to do) so people can connect and also any gaps in the official(ish) agenda can be filled by meeting like minded people.

Keeping presentation to 30 minutes. Extra detail for those interested can be do one on one in the show and tell area.

Have people demoing put a sign or sheet out showing what they are demoing so it’s easier to figure out which projects are of most interest.

Encourage others to take pictures and videos as I was either presenting or running around so took very few photographs and no video.

Here’s looking forward to the next Egham Raspberry Jam.

Went to Surrey & Hampshire Hackspace last night

I heard about the Surrey & Hampshire Hackspace early last year and even attended a meet-up before the summer in 2012 and really enjoyed it and intended to get back there again. Well, finally last night was the night and it was well worthwhile.

One of the members had arrange for us to use a warehouse location in Farnborough and so we had loads of room and bench space with wifi access.

I got the chance to talk to others who were doing interesting things with their Raspberry Pi and also show how an Arduino works and can be programmed.

Eagle Tutorial from Youtube

But for me the highlight of the evening was a tutorial on how to use Eagle (http://www.cadsoftusa.com/) by Bob. Eagle is a free or paid schematic diagram program that can also do board layouts.  I have tinkered with Eagle before and even thought I understand the fundamentals of electronics (at a very basic level) it kept giving me errors or not doing what I expected. For where I am now the free version is more than enough for me.
During the session Bob took the simple transistor switch circuit I prepared and used it as the example for finding components, placing them, connecting the nodes and duplicating them. All very useful, so now I can do more with Eagle.  Next time Bob is going to go into even more detail on what you can do with Eagle.

Then after the Eagle session Alan told me about the ULN2003 NPN 7 Darlington Array. Using just this an a SIL resistor pack for the 1K resistors I could do everything that needed 12 resistors and 4 transistors. So, lower cost, lower complexity and more reliable.

2 members of the Reading Hackspace also turned up to introduce themselves and talk about working together so as not to duplicate effort. Since Reading and Farnborough as so close to each other it really makes sense to take advantage of the opportunities this provides.  They mentioned that Reading is just about to move into a new bigger space.

Before leaving I powered up the Arduino and showed the IDE to a couple of people. Ran the Blink example  and then the Web server example just to show how easy the Arduino is to use.

Overall a great evening with some great people in a very open and sharing environment. I learned about Eagle, circuit design, a new component and how to pass command line arguments in Python.

Here's looking forward to next time.

Raspberry Pi - GPIO - Scratch - Remote Control Car

IT'S ALIVE!!!!

Tonight I wired up the remote to the circuit and the circuit to the GPIO pins on the Raspberry Pi.
Booted the Raspberry Pi and connected using Putty and Xming to get an Xwindow display on my netbook.

Ran the GPIO Scratch after installing the code I mentioned before.

 The bits of code make the car go forward, backwards and turn (forwards and backwards)

Raspberry Pi in PiBow connected to the circuit for controlling the remote control

 Ignore the Arduino in the picture I just have it attached to the

board with the proto board

When I click on the code blocks the car moved - YEAH!. So, I figured out the controls for the remote.  Make 4 small circuits to allow the GPIO Pins to activate the remote control.  With a massive amount of help from http://cymplecy.wordpress.com/2012/08/26/scratch-controlling-the-gpio-on-a-raspberrypi/ where I got the Scratch GPIO control code from I got Scratch to switch the GPIO pins and made the car move.

The quality of the car was causing some problems as the wheels would get stuck on the carpet.

This was great fun to do and as a possible beginners electronics/Raspberry Pi/Soldering/Scratch project it may suit. Wait a moment that kind of a very specific set of requirements.

Here's hoping the car is bit more accommodating on Sunday.