Le L∞p's Wiki - User contributions [en]

User:Ikerc

2013-08-20T20:03:43Z

Ikerc:

NO INFOS

2011-08-15T20:55:35Z

Ikerc: /* PCB Art */

C'est ici qu'on trouve tout un tas de propositions à concrétiser.

Tu sais pas quoi faire ? Surveille bien cette page. Mieux : [[Help:Propositions|remplis-la !]]

== Workshops ==

Voir aussi la liste des [[:Category:Workshops|workshops existants]].

=== Install party ===

Installer GNU/Linux. Essentiel, demandé, marrant, il faut le faire.

Voir : [[Install party]]

=== Dotfiles party ===

Toi aussi, viens nous montrer ton .vimrc ou ton .tmux.conf, ça sera l'occasion de faire un p'tit atelier vim, CLI, ou simplement se la raconter façon Jacky PC. Moi mon .bashrc il fait 220 lignes, et toi ?

=== Pimp my switch ===
Un atelier pour apprendre à manipuler les switchs : reset, configuration légère ou poussée.

Voir : [[Pimp my switch]]

=== Découverte de la programmation ===
L'objectif de cet atelier est de découvrir les bases de la programmation impérative, qui consiste simplement à donner des ordres à votre ordinateur (des instructions) dans un langage approprié. Accessible aux débutants !

Voir : [[Découverte de la programmation]]

=== Découverte de l'auto-hébergement ===

L'objectif de l'atelier est de couvrir les bases nécessaires pour s'auto-héberger, que ce soit sur une machine chez soi ou sur un serveur dédié.

Voir : [[Découverte de l'auto-hébergement]]

=== Découverte du HTML et du CSS ===

L'objectif de l'atelier est de découvrir les bases du HTML et du CSS mais également ce qu'est un site Web, comment ça fonctionne, tout ça tout ça.

Voir : [[Découverte du HTML et du CSS]]

=== TuneBox ===
Un atelier où on récupère des box de FAI français et on fait en sorte dans la mesure du possible de les libérer du joug de leur firmware dégueu !

Voir [[Liveboxing]]

=== LaTeX ===
Un atelier d'initiation à LaTeX, logiciel/langage de mise en page dont les seules limites sont votre imagination et le temps.

Voir [[LaTeX]]

== Conférences ==

=== Licences libres ===

Une conférence sur les licences libres appliquées aux oeuvres artistiques.

== Projets ==

=== Planet Intersquat ===
Aggrégateur de flux. La particularité : les sources nécessitent un nettoyage en profondeur (RSS foireux, mise en forme faite avec MS Word, méconnaissance des standards, etc). Éventuellement un système de scoring pour éviter que ceux qui ont une forte présence web fassent disparaître les autres.
* [[User:ToM|ToM]], [[User:Naar|naar]]

=== Synchronisation sociale ===
Interface avec les réseaux sociaux, que ce soit pour y propager les informations ou pour en faire une sauvegarde. Par exemple, en utilisant [http://fbcmd.dtompkins.com/ fbcmd], on peut sauvegarder localement tous les albums dans lesquels on est taggué sur une photo, ou poster un lien vers son site dès qu'on y publie quelque chose.
* [[User:ToM|ToM]]

=== Social Bookmarking ===
Implémentation d'un service de partage de signets, de fichiers de configuration, de scripts, ...
* [[User:Naar|naar]]

=== PCB Art ===
Vu qu'on peut dessiner [http://www.shutterstock.com/pic-30901534/stock-vector-ganesha-in-pcb-design.html tout] et [http://sbus.blogspot.com/2009/05/its-like-graffiti-stenciling-art-but-in.html n'importe] [http://www.flickr.com/photos/samwibatt/2040472729/ quoi] sur un PCB, l'idée est d'avoir une enseigne Le Loop dessinée sur un circuit imprimé. Et si ça clignote, c'est encore plus mieux. ([[User:ToM|ToM]])
* [User:ikerc]

== Idées en vrac ==
* Des soirées hacking party chaque Jeudi ! (voir [http://www.hackingparty.org hackingparty.org])
** [[User:Glenux|Glenux]]
* Infographisme : Gimp ou autres, découverte de la création graphique, design web, etc.
** [[User:Bouteilledelait|Bouteilledelait]]
* Organisation de parties de jeu de rôle ([http://fr.wikipedia.org/wiki/Shadowrun Shadowrun], [http://fr.wikipedia.org/wiki/Cyberpunk_2020 Cyberpunk 2020], ... ) ou de cartes Magic.
** [[User:Naar|naar]]
* Un bot qui nous prévient si le son s'entend trop dans la cour.
** [[User:ToM|ToM]], [[User:Strix|Strix]], [[User:Naar|naar]]
* OpenStreetSquat : service décentralisé utilisant les cartes d'[http://www.openstreetmap.fr/ OSM] et recensant les activités régulières et les évènements des squats désirant souscrire au projet.
** [[User:Naar|naar]]
* Concevoir LE thème de bureau du Loop pour les machines en accès libre.
** [[User:Naar|naar]]

== Voir aussi ==

* [[:Category:Propositions]] : les pages qui ont été correctement catégorisées :-)

2011-02-05T18:31:20Z

Ikerc:

= Led Floor =

How to turn the 11 windows of the hacklab into a big led display ?

* what have we got to do it ?
** Windows that are H189xW95.5 centimeters
** 1000 red leds
** loads of RJ45 and old IDE/SCSI/floppy buses

* what we need ?
** a system to control each diode (or group of diodes) independantly
** that is not too expensive

Question: do we need on/off for each led, or more advanced modes (eg PWM for various intensities).
* on/off:
** is simpler as regard to schematics
** is simpler as regard to driving code (led bits per image, obviously)
** isn't as cool
** can still, to some extend, allow some variable intensities
PWM "natural" ability is prefered, but choice will be made depending on total cost of solution.

== Solution #1 ==

use a TLC5940NT that can control about 16 LED each

* datasheet: http://datasheet.octopart.com/TLC5940NT-Texas-Instruments-datasheet-153017.pdf
* schematic: http://webhome.csc.uvic.ca/~mcheng/samples/led_wheel/images/hack_schematic.jpg is it me or this schematic sucks big time ??? There are examples in the datasheet, way more reliable IMO --cq
* O(price) = $180 for the 64*TLC5940NT, so we'll need also several protoboard to be cut to bind them on.

Naturally leads to a PWM version

== Solution #2 ==

use the snootlab's i2c led driver solution that can control 16 LED each

* 64*i2c led driver = 9.95*64 = 636.80
* 1*i2c shield = 17.95
* 1 ardunio = 20
* O(price) = 674.75 euros

== Solution #3 ==

* use shift registers... ?

== Solution #4 ==

use two Peggy 2 board :

* 2* http://evilmadscience.com/tinykitlist/157
* O(price) = 95*2 = $180 --or far less as you won't need the giant PCB. They have a "parts kit" that includes the 328 and the IC's for $15. you'd still need LED's and transistors and other support components. --cw

looking at the peggyLE schematics, they are not using several of the outputs, it looks like a 32x30 grid is possible with the IC's included, and by adding another IC in place of the buttons 32x45 is possible. --cw
=> they use two 4 to 16 demux for highside driving. They therefore *have* to keep one output not connected, to allow an "off" state for each of these chips. One solution would be to use two such chips, plus two generic I/O, leading to a (quite ugly) 10 to 32 demux functionality. -- cq => that's only for the 74HC154's, the STP16DP05's can use all 16, so expanding that way there can 48x30 which gives 1440 LED's --cw

== Solution #5 ==

* Check with Electrolab, where another similar project is ongoing :-)
=> actually, the (current) project there is about a 8x8x8 led cube (and some pov, too). Which are a bit different. But hey, somehow these are still led based project, so why not.

== Solution #6 ==
So, the goal is to achieve a 1024 led screen, with, if possible, PWM on each led, for a total price <150€ (connectors, leds not included) ?

My proposal would be to mix #1 (eg use TLC5940 chips, for their ability to PWM their outputs) and #4 (actually, only reuse the 4 to 16 demuxes (74HC154) idea, with two additionnal GPIO from the uC to achieve a 5 to 32 demux). That is :
* two TLC5940
** drive each row in PWM mode
** can be daisy chained, and they take 8 I/O (or possibly less than that)
** cost about 3€ each at www.mouser.fr
* two 74HC154
** drive each column (one after each other)
** cost less than 1€ each
* some power stage:
** worst case is all 32 rows ON with 100mA each. So each column power driver should be able to sustain a 3.2 A continuous current.
** the evilmadscientist schematic proposes 1.5A pnp transistors ;)
** it'd be a better idea to get some (any) tougher pnp transistors (maybe few € total)
* This requires about 18 I/O for control
** it is out of reach of an Arduino (true only when all the features of the TLC5940 are used. There are solutions to use an Arduino anyway. Note that I consider UNO and similar boards, not mega ones - which are too expensive)
** it is quite doable with a Teensy (http://www.pjrc.com/teensy/ about $30, similar in functionalities to an arduino otherwise)
* some power input is required
** I suggest a computer PSU (reuse a standard connector to get 5v on the circuit)
* some connectors are required
** I suggest using standard RJ45 connectors (which stand 1.5A if I remember well. Meh...)
* some passives are required. As usual.

Total cost: O{100€ ?). Sounds good to me :)

==== issues/open questions ====
* will the TLC be well adapted to drive each column only 1/16th of the time ? That is, still work well when asked to somehow refresh data at (total refresh rate)*(number of columns)
** according to datasheet, the max required clock speed is 4096*(refresh frequency). Even with a *16 factor, it isn't out of reach of a simple uC
** will the leds give enough light when pulsed at max 1/16th of the time at 100mA ?
*** my guess would be: yes
* how to make the board ?
** it can be done on a standard protoboard (quite small, I would even say)
*** Check if standard PC power connectors fit on these. If not, use a wire + standard connector.
*** Check if there are thru hole RJ45 connectors available. Looks like there are some (quite cheap, O{10€} for a 8 port version) but pins won't fit on a protoboard.
*** Solid core cat5 wire will fit in a breadboard, so some keystone jacks and short lengths of cat5 can be connected
* if one want to really use 12 bit resolution for each of the 1024 leds, using a 8bit uC with 8k of RAM is... probably not the best choice
** I guess it'd be okay to downgrade the resolution to few bits per led, eg never drive LSBs for each led and use only 4bits resolution.

=> I cannot see any big flaw in this solution. Does anyone have a better view here ? --cq
* "it is really an issue to be unable to buffer data"
** wouldnt some usb to serial chips have some additionnal RAM ?
* "it wouldnt hurt to have some more processing power onboard"
* "you're such a p... to use monochrom leds"

== Solution #7 ==
Similar to #6, but instead of TL+demux, use a uC which has 64 I/O that can be dedicated to the led matrix.
* I cannot think of any chip that would be as cheap and as "simple"
* software layers would be easier
* additionnal power/interfaces would be required to drive the rows
One possible solution:
* use this : http://www.atmel.com/dyn/products/tools_card.asp?tool_id=4114 + an ugly extension board (on a protoboard) with 64 pnp. Someone at Electrolab can provide that board
* then, in a second design iteration, design a full custom board with this chip + transistors, connectors, ...

== Solution #8 ==
* 42 ?

== Solution #9 ==
* Use the stm8s-discovery kit (~9€, farnell)
for 9€ you have a stm32bits uC to upload the stm8its the stm32b can be hacked ?
*I've 2stm8s-discovery and if you like to test. st-IDE run only on windows can be hacked to run on linux ?