Show Posts
Pages: [1] 2 3
1  Using Arduino / LEDs and Multiplexing / LED Matrix troubleshooting on: February 16, 2011, 03:43:34 pm
Hi everyone.
I'm trying to get a LED matrix to work with:
- a MAX7219 IC
- an Arduino
- this lib: http://www.arduino.cc/playground/Main/MAX72XXHardware

The problem is that my LED matrix refuses to display anything but "all the leds on". I've triple-checked the wiring, tested everything, and in last resort I this my matrix could be a common cathode one...
Do you know how I can test wether it's a common anode or cathode?
2  Forum 2005-2010 (read only) / Français / Re: 24V... on: January 23, 2011, 04:13:22 pm
Found out exactly what I need here: http://itp.nyu.edu/physcomp/Tutorials/HighCurrentLoads

Thanks for the TIP120 advice!
3  Forum 2005-2010 (read only) / Français / Re: 24V... on: January 23, 2011, 01:40:34 pm
Les TIP120 c'est des paires de darlington, non? Il y a-t-il un moyen d'en créer un avec des transistors normaux (cf schéma sur la datasheet)?

Et au sujet des 24V, moi aussi j'ai été surpris, mais apparemment c'est bien ca!
4  Forum 2005-2010 (read only) / Français / 24V... on: January 23, 2011, 12:56:33 pm
Bonsoir tout le monde.
J'ai mis la main il y a peu sur un compte-tours de voiture, et j'aimerai bien pouvoir le contrôler avec un arduino. Après quelques essais, j'ai trouvé les deux broches qui permettent de déplacer l'aiguille. D'après mes essais, il faut environ 24V pour qu'elle atteigne son maximum.
Et c'est là que je suis un peu embêté: comment utiliser un arduino pour faire varier une tension entre 0 et 24V?
5  Forum 2005-2010 (read only) / Français / Servo qui tourne trop! on: August 22, 2010, 09:30:07 am
Hello tout le monde smiley-wink
J'ai un petit problème avec un servo. C'est un modèle super simple, le GWS S03N.
Je l'ai connecté à l'arduino comme suit:
-marron -> GND
-rouge -> +5
-orange -> pin n°9

Et là, pas moyen de l'utiliser comme un servo normal. Je veux dire par là que lorsque j'écris une valeur, il tourne dans un sens ou dans l'autre, toujours à la même vitesse, et ne s'arrête que si j'utiliser servo.detach().
Quelqu'un a une idée de comment lui passer des angles?

Je colle ici le code utilisé pour le test.
Quote
#include <Servo.h>

Servo myservo;  // create servo object to control a servo

int pos = 0;    // variable to store the servo position

void setup()

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object
  myservo.write(30);


void loop()

  


6  Forum 2005-2010 (read only) / Troubleshooting / Re: LCD (16x2) GDM1602a on: June 06, 2010, 01:39:44 pm
thx for answering!
I had trouble, but everything works fine now. I had no 10k potmeter, but using two 10k resistors just works fine.
Thanks again.
7  Forum 2005-2010 (read only) / Troubleshooting / Re: LCD (16x2) GDM1602a on: June 06, 2010, 09:55:12 am
Hi everyone.
I have exactly the same problem with exactly the same LCD, but I can see the black boxes.
So everything's fine but I cant print anything on my LCD smiley-sad
8  Forum 2005-2010 (read only) / Development / Re: Need a powerful multiplexer... on: August 19, 2010, 03:22:05 am
Wow, I just took a look a the TLC's datasheet, I think this baby's just took complicated for me! But I haven't mentioned that I just have figured out how to handle a SN754410 and didn't succeeded with 74HC4051 smiley-wink
9  Forum 2005-2010 (read only) / Development / Re: Need a powerful multiplexer... on: August 18, 2010, 07:09:42 pm
Could you develop a bit ?
10  Forum 2005-2010 (read only) / Development / Need a powerful multiplexer... on: August 18, 2010, 05:37:20 pm
Hi everyone.
I was thinking about a nice project that would be interesting to develop: a LED clock. Here's how I imagine it (roughly):


I was wondering if there's a multiplexer huge enough to handle, let's say:
- 1 LED / second = 60 LEDs
- 2 extra LEDs / 5 minutes mark = 24 LEDs
- 4 digits, 9 LEDs high * 5 LEDs width = 27 LEDs
- 1 comma = 2 LEDs
Total: roughly 110 LEDs...
So I need a 7bits multiplexer? a 128++ pins monster? Does it exist?
11  Forum 2005-2010 (read only) / Interfacing / Re: Need more power. on: August 30, 2010, 02:04:26 pm
Lol, how stupid  ;D
12  Forum 2005-2010 (read only) / Interfacing / Re: Need more power. on: August 30, 2010, 08:28:53 am
Indeed! Do you think this would be enough?
13  Forum 2005-2010 (read only) / Interfacing / Re: Need more power. on: August 30, 2010, 08:22:09 am
What about 8 AA? I could get 9.6V and up to 8*2700=2.16Ah !
14  Forum 2005-2010 (read only) / Interfacing / Re: Need more power. on: August 29, 2010, 05:01:22 pm
Unfortunately no. I knew that these batteries are less powerful than multiple AA batterie...but the problem is that 9V battery is small enough to fit my project in terms of size. 4 AA would fit too, but deliver only 6V where I need 9/10 V.
15  Forum 2005-2010 (read only) / Interfacing / Need more power. on: August 29, 2010, 04:49:51 pm
Hi everyone.
I have a little problem. I have an Arduino Mega, a 128*64 GLCD, a 9V futaba servo (soon there will be another) and a 9V geared motor. The whole is supplied with a regular 9V battery.
When I reset the arduino, my program draws things on the LCD and then operates (at this time) the servo only. And here's the problem: when the servo works, the LCD dims. I think I need a bigger power source? Or something else? What would you recommend? Knowing that I really would like to have only one 9V power supply that my model can carry away.
For more details about the project itself, check my blog out: http://hexecute.blogspot.com

Thanks smiley-wink
Pages: [1] 2 3