June 4th

hi fellow mortals,

Another META Monday Meeting report

  1. Picnic'07 Workshop update
  2. Tim en David from Blendid.nl
  3. Heerko's miniworkshop on Eagle

A little update on the Picnic'07 workshop:
The structure of the MAKE part of Picnic is still under construction, it has changed. Right now the idea is to have three parts: RFID, Location Based Media and Virtual Worlds.
Mediamatic will take care of teh RFID part, de Waag will take care of LBM and about VW I don't know. So that makes the topics not very META-like. Not very hardware oriented. I have to wait for final plans from the Picnic organisation. I'll follow up on it.

Tim and David are blendid and the make all kind of games, installations, environments etc... (check out the website)
They showed an RFID circuit. It is palm sized, capable of reading low-frequency RFIDtags and connected to the computer by a serial Bluetooth connection.
The readerpart is called id20, also smaller available (id12). The latter is smaller, but has less antenna. They cost ?10 (small) and ?11 (larger)
The bluetoothconnection goes via the Bluesmurf chip ($60 rfidshop.com, uk, expensive delivery)
The IC works on 9V and an adaptor to 5V.
Max/MSP and other apps can read the data from the serial port.
This is an example of a relatively cheap RFID reader.
tags are about 2 euros a piece.
The system is low frequence, which means a not so high datarate, ideal for simply reading serialnumbers from tags. High frequency systems are suitable when you want to program the tag.
There is also an arduino with Bluetooth technology, it costs about Ä70 and might be an alternative.
They also showed some of their projects. First the world famous Doom for the Blind: a headset tracing the movement and direction of the player. Sound, not Vision, is the cues that the player gets. He can then shoot the monsters by aiming and pulling the trigger of the joystick in his hand.
Right now they're working on wixels, wireless pixels. 2000 individual bulbs to be arraned in an environment. They can take any color at 25(? maybe it was 50) Hz, controlled wireless. (I forgot the rf-protocol name) They are controlled centrally and all listen untill their individual appropriate colordata comes by. Cool stuff.


To supplement Barts excellent notes below, here are some links that I used to learn Eagle (and I almost literally used this meeting), all made by the same guy:
- Draw Electronic Schematics with CadSoft EAGLE
- Turn your EAGLE schematic into a PCB
- Make hobbyist PCBs with professional CAD tools by modifying "Design Rules"
And if you are feeling particularly bold:
- How to make a custom library part in Eagle CAD tool (Haven't tried this one myself.)
- Help file & tutorial from the Cadsoft site

If you want to your schematic to the physical realm, take a look at my Toner PCB etching How To.

Then Heerko's miniworkshop on the Eagle IC drawing program.
In case you don't get to the end (it's a long read) Thanks Heerko! I really liked it.
Drawing in Eagle consists of two parts:
First: connecting the different elements of your IC in the right sequence.
Second: drawing the actual physical layout.
To start: install the Eagle programm. It is freeware available with some restrictions. (only one project open at a time, spatial limitations of the board design etc) http://www.cadsoft.de/cgi-bin/download.pl?page=/home/cadsoft/html_public/download.htm.en&dir=eagle/program/4.1 See Heerko's mail for more details/thingies on this subject.
(I write this from a Mac OS X perspective)
You need X11 installed to run Eagle, find it on your install disc or somewhere else. It looks like the terminal interface but is capable of Graphic representation.
Goto the bin folder in Eagle and run "./eagle"
A GUI pops up.
New > Project
New > schematic
Make sure you save the project and the schematic before you resume. It gives the project a name. (I didn't pay a lot of attention on this stage, I was catching up installing Eagle)

We will now add a IC-component to our scheme:
Click the Library button at the toolbar located at the left. The icon is a logic gate with a cursor arrow pointing at it.
A (immens) list of IC components pops up. Use the search function to find a 555. No, "555" doesn't work, look for "timer".
By selecting a component you see some extra information on the right. This information deals mostly about SPATIAL information about the components. It does not say anything about (for example) resistor values or so. We're desinging spatial layout here, not the circuit itself. You're supposed to have done that earlier. (fool!)
Since spatial info is important be aware of things like distance inbetween pins, using SMDcomponents or DILcomponents. All this is shown in the extra info to the right.
If you, by accident, click "drop", you remove a library from the list. The lib is not gone for ever. You just need to "use" it again. Goto the Library pulldown in your main screen --> use --> select the library you need and click ok. If you don't know which lib you dropped, just select all. Just like you do in the pizzeria every sundayafternoon.
You've found the 555, click ok, click on the scheme and the component is dropped on the scheme.

Manipulating components:
select a tool from the toolbar. E.g. "move", or "rotate", or "delete". With the tool selected you can click components and they will perform actions according to the tool. The second and third button on your mouse will perform rotation and move actions as well.
Use "Net" (almost at the bottom of your toolbar) to connect pins.
To make it easier to point at pins and other connections: click "Display" from the toolbar (almost at the top), select "Pins", "ok". Now pins will show a clear clickarea indicating where to click in order to connect them properly.

We made the following:

You're now done connecting all the components, we move to the physical lay-out.

When you're done: "save", "File" --> "Switch to Board"

You see the board topview. The components lay ontop. The trace run underneath the board.
Move the components into the white frame. (select all with the select tool and drag holding the rightmousebutton)
I use the freeware version and therefore there is a spatial limitation.
The frame can be made smaller (drag the borders)
Then hit "autorouter".
In the dialogue box put "Top" to "N/A". This disables a second (top) layout. We will etch only one side (bottom) of the board for simplicity. The other side will contain all the components.
The straight yellow lines (airtraces, symbolic connections) become jagged blue lines. (copper) These are the lines as they will be etched. If still yellow lines are left you have to move around the components in order to make the yellow lines disappear. Move them around and hit the "autorouter" again. It's trial and error. The "Ripup" tool turns copper into airtraces again.
You can also modify your scheme or you can add jumpers to your scheme. These jumpers provide a bypass on the component-side of the board.

Backforward connotation: As you alter your scheme and your Board-window is open, the component and its connections are instantly added. If your board-window is not opened errors will occur.

Eagle default layout rules are focussed on industrial conditions. Not very handy for DYI nerds. We cannot etch as precise, and we cannot drill holes as small as industrial producers can. So the width of the coppertraces needs to be altered, just as the size of the Vias, the space inbetween traces etc...
Default is 8mil (indicating some size, I don't know), Heerko decided to change most of them:
->0.8mm for wire, pad and via
->0.45mm inbetween 2 pads
Hit the "Drc" button. "Clearance", Put all values to 0.8mm. pad x pad to 0.45mm "Sizes": put first two values to 8mm
"Restring": ->"Pads, Bottom" --> 0.6mm, 25%, 0.6mm
-> "Vias, outer" --> 0.6mm, 25%, 0.6mm
-> "Vias,inner" --> 0.6mm, 25%, 0.6mm
I just reproduced these values as Heerko told them. It might very well be possible that your board will produce errors due to your alterations. (traces suddenly shortcircuit) In that case you need to find out what dimensions have changed and alter your Drc accordingly.

Plains: big fat trace. enter the following in the commandline: "poly gnd" and then draw a line around the outer edges of the board. Hit button "rastnest". A shape of copper will be drawn connecting all the GND wires. It saves you etching acid.

That's about it.

Some details:
When using a packagecomponent; a component that holds multiple circuits that function independently. For example the 4066 which holds 4 independent switches.
These switches are all drawn independently and on different locations in your scheme. Though they are drawn as one component on your board because that's their actual shape (4 in 1). Eagle knows this and arranges it for you. As you add more than 4 swithes to you IC it will start a new package of switches. In your board layout this will be drawn as a second chip.
These 4 switches share powerpins: IRL there are less powerpins than switches. Eagle knows this and draws just enough powerpads. There are multiple solutions to get Eagle to do this for you. In your Scheme click the "Invoke" tool and click the component. Select "Power" from the popup and a power element is drawn in your scheme. It will also appear in your Board.
There was also a solution with naming main power and main GND according to a convention. But I forgot the details. Heerko and Marc know more.

May 7th

The first topic was the workshop at Picnicí07. Some more explanation was given about the actual setting of it all. In contrary to last year a part of the festival will be free to the public to enter. The workshop will be done in a zone where the audience is a mixture of people that pay and people that donít pay. We will not be some kind of a Ďpartnerí of the festival that has to contribute with money or so. We are simply invited to do a workshop, and thatís it. I didnít talk about money yet to Ramon because he was still busy arranging funds. I expect that we will be compensated for the costs etc. More info later

Then there was a discussion about the channels we want to use to promote META. There seemed to be a misunderstanding about Virtual Platform. Some thought that we were asked to blog on it. Others believed it was simply a request to deliver a description of META. More info follows. The overall feeling is that we should never Ďbelongí to a big(ger) organization. Still there has to be made a distinction between broadcasting through a channel and being owned by a channel. A blog on our website was suggested. The overall reaction on that was that it would be more work and not beneficial to ourselves. It would require regular postings, mainatanance etc. In line to the blog suggestion there was the suggestion to open the archive. So it becomes a resource of information, also available to people that are not member of the mailinglist. Compared to a blog the advantage would be that it doesnít require any extra effort and it reflects exactly our interests. The only disadvantage is that our email addresses are revealed. There is thing like email-obfuscation but if itís done on all similar wiki-systems in the same way ( spam_me [a]please[dot]com ) itís still easy to crack and wonít protect our addresses. Dirk, can you find out if there is a way to work around this?

Then there was the topic of becoming a Stichting. The financial flows will be placed under a Stichting of Marc. This will take effect from the 7th workshop. The implication most visible will be a raise of 19% of costs. So workshops will be about Ä10 more expensive. The advantage is that itís all legal and that on the long term there will be no unforeseen consequences for those who handle finances right now. Audit costs will be around Ä100 per year. Starting our own Stichting would costs 200 tot 500 euros therefore it is easier to move it to Marcís. Also the statutes of his Stichting allow the activities that META is about

Then there was something about METAís financial buffer: itís too small. The overall message was that we need to pay a little extra or we structurally need more participants per workshop. I think we made a good start with Tomís fully booked workshop.

And as a final remark: everybody is enthusiastic about Heerkoís upcoming eagle-mini-workshop!

April 2nd

Niels had two topics to discuss: - the upcoming workshops - next meetings program

Workshops: There are two workshops coming up. One by Marc and one by Tom Schouten. Marc's workshop will be held the weekend of 28th and 29th of april. He will discuss low power design. Or short: all about battery operated electronics. This covers hardware issues, software tricks, wearables, powerbudgetcalculations and a discussion about the typical powereaters in a cicuit.

Tom will be in Amsterdam from half may till half june. He is a Forth- evangelist (PB and also connected to goto10.com) and will discuss realtime videogeneration by programming a pic chip or basic stamp with Forth. The hardware will not be the biggest part of the workshop, this time it will be mostly about programming in Forth. It can be done on the same chip as we used in Johannes' workshop. It will not be possible to program Forth on the arduino. Next week a public announcement about this workshop. Very probable that META members will be a minority.

META monday: next meeting, Niels will do a mini workshop about analoge filters.

Keyboard hack by Heerko Imagine a blob on a tripod. In the blob a motor handle is intergrated. By twisting the handles a DVD menu is controlled (up down and enter). heerko modified a keyboard chip to use the up, down and enter. The advantage is the standard protocol of the keyboard. It is a so called Human Interface Device and is recognized as such by the computer. No messy software hacks are needed. You only need to control the keyboard circuitry. The keyboard works as a relais (dunno exactly how anymore) 8x17 excluding the modifiers like ctrl, shift etc... Problem in DVD menus is the fact that a menu item does not have an absolute number, there is only up and down, not 1 to 5 e.g. Software exists to emulate the HID. It makes it possible to make aUSB interafce recognized as a HID (which is different from for example a printer). This way a pic chip (arduino) can become a keyboard instead of a comport (is my terminology right here?)

Nielsie was trying his luck by randomly connecting the pins of a live keyboard. It didn't work and Marc told afterwards that it is very easy to burn it that way. :)

An if you need a dremel drill, don't buy it at Rotor but at Hecke. Rotor is 9 times more expensive. (heerko told us)

And last but not least: Heerko and Niels are conducting a workshop at the Brakke Grond. There is a Vlaamse Media festival. Currently the brakkegrond.nl website is somehow down (can't Swummoq fix it?) so I can't give you all the details about the circus. It's called Club Victorian Circus and is about installations, media art, workshops, etc...

 From wednesday there will be visible results from the workshop. Go  

and see!

March 5th

What we discussed today:

First Eric showed the cable he made according to the directions on the Arduino page. It's a parallel-port to 6 pins cable and allows to program the chip on the Arduino and program a bootloader to it. The parallel "bit banging" is done by the software. In the case of a USB programmer, the "bit banging" is done by a microcontroller in the programmer.
Eric also showed an accelerometer/tiltsensor on a breadboard connected to his Arduino. It controls a pad in a pong game. This time not only left to right, but also to the forward/backward providing the diehard pong addict a unique opportunity to pinpoint the opponent right at the net with a severe stop-volley strategy. You can see a demo movie here

Hurk did the etching trick again with an improved process: press n peel. A special paper that you laserprint the IC on. It makes sure that the toner is transferred as efficient as possible, much better that the glossy photo-paper from before. Iron it on the copper and etch it with the good old HydroPeroxide-HydroChlolicAcid mix. The paper can (amongst other places) be found at pcb-store.com.
(That's where I bought it... [Hrk])

A second improvement was to keep the process as clean as possible: don't grind the copperplate with the press and peel paper nearby. The dust pollutes the paper. Also cleaning the copper after grinding should not be done with thinner: too fatty. Use detergent or alcohol.

For the Max/MSP fellows amongst us: Sylvain showed a new object called aka.wiiremote which is able to read out WiiRemote values. All that's left to do is to buy a WiiRemote for approx. Ä40. http://www.iamas.ac.jp/~aka/max/ There are some more nice objects to be found at the site.

And we had a special guest: Rui Guerra from V2_.
A little recap of his story. I won't tell about the soft-object he showed but about UnDeaf he's organizing. He would like people like us to participate
He provides a room and basic facilities like lighting, a wireless connection and stuff at the same time as the official Deaf'07. It is not an anti-DEAF'07 thingie, it's an informal add-on. He invites people to show their current projects, what they have done in the past and to discuss what's on their mind. People will be performing, watching, listening. There will be no time schedule and no restrictions, there will be no best and no worst. He aims at a sort of natural selection where people end up doing and discussing what they find most interesting.
There is more information at the undeaf website: http://www.undeaf.v2.nl It's a wiki and you're free to add your name, edit information, etc...

He needs more people that show, perform and help organize the weekend. He told me there will be some sort of deal with free entrance to the 'real' DEAF'07 festival.
For exact details: check the wiki.