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871  Using Arduino / Project Guidance / Re: Controlling VFD using arduino - 0-10V PWM Output on: August 14, 2013, 01:29:52 pm
http://forum.arduino.cc/index.php?action=dlattach;topic=94426.0;attach=14482

(opens a pdf, 1 pg.)
872  Using Arduino / Motors, Mechanics, and Power / Re: Electric Bike with Arduino UNO (48v-64v) on: August 14, 2013, 06:38:27 am
It was something to do.
Never did anything like that before.
873  Using Arduino / Project Guidance / Re: Few questions on using transistor for pwm LED control on: August 13, 2013, 09:15:57 pm
Is there something similar that can perhaps amplify the Arduino's switching frequency to work with higher voltage and current...? I assume that would be more efficient than using a transistor since less power will be used overall. Is this true?

How do you mean?
What's efficient depends on how it's used.
874  Using Arduino / Motors, Mechanics, and Power / Re: Electric Bike with Arduino UNO (48v-64v) on: August 13, 2013, 09:13:27 pm
http://incredulist.blogspot.com/p/e-chopper.html

http://hackaday.com/2012/06/29/electric-bike-earplugs-not-included/#comments
875  Using Arduino / Programming Questions / Re: Question about using arrays on: August 13, 2013, 08:47:17 pm
Because they're characters, "special case."
876  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 13, 2013, 06:20:29 pm
firashelow,
I made a mistake in my sketch; it's the functions calls - I forgot the parentheses.
I'm surprised that nobody has come along to ball me out, yet.
Please try this:

Code:

byte latch = 8;
byte clock = 9;
byte srdata = 10;

//byte pattern1 B11111001;  // 1
//byte pattern2 B10100100;  // 2

void setup ()
{
  pinMode(latch,OUTPUT);
  digitalWrite(latch,LOW);
  pinMode(clock,OUTPUT);
  digitalWrite(clock,LOW);
  pinMode(srdata,OUTPUT);
  digitalWrite(srdata,LOW);
}

void loop ()
{
  // make a 1
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,HIGH);
  clockit();  
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,LOW);
  clockit();
  digitalWrite(srdata,LOW);
  clockit();
  digitalWrite(srdata,HIGH);
  clockit();  
  latchit();
  
  delay(1500);
  
  // make a 2
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,LOW);
  clockit();
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,LOW);
  clockit();  
  digitalWrite(srdata,LOW);
  clockit();
  digitalWrite(srdata,HIGH);
  clockit();
  digitalWrite(srdata,LOW);
  clockit();
  digitalWrite(srdata,LOW);
  clockit();
  latchit();  
  
  delay(1500);
}

void clockit ()
{
  digitalWrite(clock,HIGH);
  delay(1);
  digitalWrite(clock,LOW);
}

void latchit ()
{
  digitalWrite(latch,HIGH);
  delay(1);
  digitalWrite(latch,LOW);
}
877  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 13, 2013, 03:15:20 pm
Do you have a voltmeter?
878  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 13, 2013, 01:24:10 pm
OK, I cannot see everything, the wires are long and hide things.
It looks OK, but I cannot say 100% because I cannot see it all.

What is the source of these 74HC594 ICs? (Where are you getting them from?)

The shift, latch, clock operation of the '594 and the '595 are the same (the "tri-state" is a critical difference, but that is not why this is not working.)
879  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 13, 2013, 10:03:16 am
Is this built on a "breadboard"?
Take a good picture of that with all of the wires visible.

In my test sketch, I digitalWrite a HIGH or LOW on the srdata pin.
Then I clock the data (clockit).
It goes through that 8 times and then the data gets latched (latchit).

Don't connect 5 and 10.  5 or 10, it doesn't matter, one or the other.

The '594 is similar to the '595 but the '594 is not suitable for this two-digit display.
The '595 has a tri-state output, that pin (/G) "disconnects" its outputs from the display (data bus.)
880  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 13, 2013, 07:57:32 am
... 270 ohms is that ok to use for the finished project ?
Not if you ask me.

i connected both commun to +5V nevertheless i see an X on one of the wires in your schematic ?
I meant for that not to be connected, but it doesn't make a difference here.

and for now the patterns that i see are : 8.8
At this point, I think that your shift registers are bad (maybe from having had them connected to 12V, maybe from having the outputs shorted to other outputs - I'm not M.R.B.)

by the way, why the data clock and latch are byte and not int ?
A byte is less than an integer, I just use what's needed.  Why is int used with wild abandon?

6mA ! i didn't know anything about it, that is so little current
It's a plain fact from the datasheet, it's right at the top (upper left)
http://www.jameco.com/Jameco/Products/ProdDS/916351.pdf

and how much current does the display need because my datasheet say nothing about it just the diagram is it about 20mA for each LED or way less ?
20mA is the most any segment should get (or have, whichever.)

So, do you have any more shift registers?
If you buy any, get 74HC595 and then do nothing till you get instructions, as you need a lot of guidance.
I'm not trying to be mean, but I don't know how else to put it.

M.R.B. -- http://wiki.answers.com/Q/What_does_a_material_review_board_do
881  Using Arduino / Installation & Troubleshooting / Re: Serial Port already in use AND Serial Port greyed out. on: August 12, 2013, 09:06:40 pm
On XP --
  • I plugged in a Uno and waited for it to "fail"
  • I got into Control Panel, got into device manager and right clicked on the Arduino Uno (it was Question Marked) a selected Update Driver
  • In the Wizard I clicked the radio button for Browse my computer and waded down the folder tree (the Arduino root) till I got to the Drivers folder (you won't see arduino uno.inf in a list*)
  • I went with 'OK' and/or 'Next' when prompted from there and on

I'm sorry that this has been such a pain for you.

The device the Uno has in place of the FTDI used previously is a programmable device.
But it cannot be casually reprogrammed

* You can find it by Searching for it or by opening the folders till you find it.
882  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 12, 2013, 08:41:00 pm
Wire up an Arduino, with one shift register, and the two-digit LED
as shown in the attached drawing - no more, no less.

Then upload this sketch:
** BAD CODE ** BAD CODE **
I forgot the parentheses with the function calls
[dadgummit]
Please see Reply #40
(Aug 13, 2013)
Sorry!

That is all.

Code:
// firashelou1
//
//

byte latch = 8;
byte clock = 9;
byte srdata = 10;

//byte pattern1 B11111001;  // 1
//byte pattern2 B10100100;  // 2

void setup ()
{
  pinMode(latch,OUTPUT);
  digitalWrite(latch,LOW);
  pinMode(clock,OUTPUT);
  digitalWrite(clock,LOW);
  pinMode(srdata,OUTPUT);
  digitalWrite(srdata,LOW);
}

void loop ()
{
  // make a 1
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,HIGH);
  clockit;  
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,LOW);
  clockit;
  digitalWrite(srdata,LOW);
  clockit;
  digitalWrite(srdata,HIGH);
  clockit;  
  latchit;
  
  delay(1500);
  
  // make a 2
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,LOW);
  clockit;
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,LOW);
  clockit;  
  digitalWrite(srdata,LOW);
  clockit;
  digitalWrite(srdata,HIGH);
  clockit;
  digitalWrite(srdata,LOW);
  clockit;
  digitalWrite(srdata,LOW);
  clockit;
  latchit;  
  
  delay(1500);
}

void clockit ()
{
  digitalWrite(clock,HIGH);
  delay(1);
  digitalWrite(clock,LOW);
  delay(1);
}

void latchit ()
{
  digitalWrite(latch,HIGH);
  delay(1);
  digitalWrite(latch,LOW);
  delay(1);
}

I'm not trying to make a speedometer for you.
I'm trying to help you see how this thing works and to get a handle on this situation (for my own reference and yours.)

I need to add that each output of a 74HC594 is only good for 6mA (if ratings mean anything to anybody around here lately).  
Your resistors are a little low, 470Ω would be better, but we'll continue.

883  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 12, 2013, 05:40:31 pm
ok great i understand, but which left and right shift you are talking about ? because the shifts are independent from each other

Regardless - it doesn't matter.

The "shifts" may be independent, but you are placing the outputs of the one ("left") in parallel with those of the other ("right") when they are connected to the segments of this two-digit display of yours.
884  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 12, 2013, 03:57:21 pm
We'll talk about one segment, one cathode, of your situation with this two-digit display, "a".
It is connected to the outputs of two shift registers.
You have a two-digit CA 7 segment, it has a left CA and a right CA, but the segments are shared.
[You understand the concept of sharing (to share), yes?]

If either of those outputs goes Low then the segment will light - no matter which CA is High (+):
when the left CA is High then the Left "a" segment will be on, when the right CA is on then the Right "a" segment will be on.
If the left register (MSD) was filled with B11111111 and the right register (LSD) was filled with B00000000, the LED will have a path to Ground.
If the left register (MSD) was filled with B00000000 and the right register (LSD) was filled with B11111111, the LED will have a path to Ground.
885  Using Arduino / Project Guidance / Re: A problem with my circuit, shift registers, LEDs and display !! help ?! on: August 12, 2013, 11:04:11 am
i didn't get why it's wrong ? because my arrangement is same as yours ! shift outputs are connected to resistors and then to display pins isn't this what you mean ?

I guess you have two schemes, maybe three.
If you are using the one shown in the middle then that is partially correct.
So, you understand that there is one set of segment cathodes and two CAs.
As the segment cathodes are "shared", when one shift register has a Low on "a" and the other shift register has a High on "a" (it is the same "a" segment either way) then that presents a problem - whether the CAs are toggled or not (it looks they are not anyway, but no difference.)

Set this up with one shift register connected to the two digit display.

[Please give the exclamation marks (" ! ") a rest.]
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