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271  Using Arduino / General Electronics / Re: 5volt pin causing board to shut off on: December 31, 2012, 08:10:35 pm
Show us your circuit, how you wired up the dickson charge pump?
272  Using Arduino / Project Guidance / Re: Arduino powered fan on: December 30, 2012, 08:16:51 pm
A CPU fan. Powered by USB. Off, Low, High
Where the Arduino come into play?
Do you need arduino to control the 3 way switch?
273  Using Arduino / General Electronics / Re: Blown Caps in 0-30v 0-10a bench supply repair on: December 27, 2012, 04:19:08 am
Here is the circuit diagram that I have found from Chinese website, it may be not the same as what you have but you got an ideas of how this type of power will look like.
 
And here is the manual explain the working of the power supply almost the same as this circuit diagram, hope it can help.
POWER SUPPLY USER MANUAL
274  Using Arduino / Project Guidance / Re: help please on: December 04, 2012, 05:46:02 am
Is it some thing like this?

http://www.gt-kontiki.co.nz/
http://www.gt-kontiki.co.nz/downloads/2012%20GTK%20Complete%20User%20Guide.pdf
275  Using Arduino / Project Guidance / Re: Trying to make a simple clock on arduino for project on: December 04, 2012, 01:12:12 am
Here are some basic code to display time without RTC
Code:
// include the library code:
#include <LiquidCrystal.h>
#include <DateTime.h>

#define DEBOUNCE_TIME  40 // switch must be pressed at least this number of ms
#define CLOCK_ROW  0
#define CLOCK_COL  0
#define NO_SWITCH  255  


// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);


void blinkingCursor(boolean enable){
  if(enable)
    lcd.command(0xf);  // blink cursor
  else  
    lcd.command(0xc); // just enable the display
}

void setup(){
  Serial.begin(9600);
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.setCursor(0,0);
  lcd.print("LCD Key Shield");
}

void loop(){
  if(DateTime.available()) { // update clocks if time has been synced
    digitalClockDisplay( );   // update digital clock
  }

    if(DateTime.available()== false)
{
    DateTime.sync(1230768000); // if clock was never set,  start at Jan 1 2009
    DateTime.available();
}

  delay(100);
}

void digitalClockDisplay(){
  // digital clock display of current date and time
  lcd.setCursor( CLOCK_COL, CLOCK_ROW);  lcd.clear();  
  if(DateTime.Hour < 10)
    lcd.print(' ');
  lcd.print(DateTime.Hour,DEC);
  printDigits(DateTime.Minute);
  printDigits(DateTime.Second);
}

void printDigits(byte digits){
  // utility function for digital clock display: prints preceding colon and leading 0
  lcd.print(":");
  if(digits < 10)
    lcd.print('0');
  lcd.print(digits,DEC);
}

the information that is sent is a standard way of encoding date and time, sometimes called unix time (see http://en.wikipedia.org/wiki/Unix_time)

This time format is supported by most operating systems and programming languages. The  download for the DateTime library includes a Processing sketch that gets the time from your computer and sends this to the Arduino sketch.

The header is there to provide a way for the sketch to recognize the start of the time packet.
276  Using Arduino / Project Guidance / Re: Control PC power with arduino on: November 29, 2012, 08:04:51 am

I relation to distinguishing between power sources I found interesting article here:

http://code.google.com/p/tinkerit/wiki/SecretVoltmeter

So as I can understand I can measure the voltage of the power source, assuming that USB power voltage is about 5V and I will use external power adapter producing 12V I should be able to use "SecretVoltmeter" approach to recognise which power source is currently connected ? Do you think that would work ?
You can't use SecretVoltmeter , it measure the voltage of the AVcc, which in both case all 5V.
Well, looks like this SecretVoltmeter is used in this project:
http://provideyourown.com/2012/secret-arduino-voltmeter-measure-battery-voltage/
where you can test the voltage of the battery powering the arduino, from that article:
"
...
You could also use it to determine if you are connected to a power source or running from batteries.
...
"

so maybe there is some change still ?!

Yes, may be 5% to 10% of 5V.
277  Using Arduino / Project Guidance / Re: Control PC power with arduino on: November 29, 2012, 07:26:54 am
   
Thnx, I'm total noob in electronics I suppose that the easiest thing you be just use another relay which will be set to ON state when the power adapter is on and I will just read state of the relay using one of arduino PINs ?
You probably don't want a relay, since those are fairly slow acting, but an optocoupler is essentially a relay.
I don't mind about the speed as that relay will just be used to inform arduino that power adapter was trunde off, but optocoupler looks as more natural solution - as I said I'm total
noob in electronics so wish me luck !


I relation to distinguishing between power sources I found interesting article here:

http://code.google.com/p/tinkerit/wiki/SecretVoltmeter

So as I can understand I can measure the voltage of the power source, assuming that USB power voltage is about 5V and I will use external power adapter producing 12V I should be able to use "SecretVoltmeter" approach to recognise which power source is currently connected ? Do you think that would work ?
You can't use SecretVoltmeter , it measure the voltage of the AVcc, which in both case all 5V.
278  Using Arduino / Project Guidance / Re: Lighting Lots of 1.2v Bulbs...or Bright LEDs on: October 16, 2012, 09:50:12 am
If you use LEDs, you may try Charlieplexing
http://www.arduino.cc/playground/code/charlieplex
With 6 Pins you can control 30 LEDs.
279  Using Arduino / Project Guidance / Re: Okay, how do I control a PC fan with the LCD screen ie faster or slower? on: September 23, 2012, 05:19:10 am
You can read this A Complete Beginners Guide to the Arduino. to learn how to connect the push button in Project 4.
280  Using Arduino / Project Guidance / Re: 5v down to 3.3v for 3.3v sensitive devices on: August 09, 2012, 05:36:12 pm
May be you can did it yourself without waiting for stock.


http://www.rocketnumbernine.com/2009/04/10/5v-33v-bidirectional-level-converter
281  Using Arduino / Project Guidance / Re: Hi, My fading PWM Leds aren't fading the way they should be... on: July 03, 2012, 07:39:08 am
The way you used to correct the negative value was incorrect, you can't any value less then 128,
try this code

Code:
    // set the colours and correct for negativity 
  int RedValue = (raw.XAxis>0?raw.XAxis:((raw.XAxis+256)/2)) ;
  int GreenValue = (raw.YAxis>0?raw.YAxis:((raw.YAxis+256)/2)) ;
  int BlueValue = (raw.ZAxis>0?raw.ZAxis:((raw.ZAxis+256)/2) ;
282  Using Arduino / Project Guidance / Re: volatage regulation on: July 02, 2012, 06:41:15 am
Here are some of the links

Voltage Boosters
A simple regulated DC-DC booster for up to 60V 1/4W. It uses no special ICs, just basic
components and two pins from the Arduino.
http://www.arduino.cc/playground/Main/RegulatedPositiveVoltageBooster

Buck–boost converter
http://en.wikipedia.org/wiki/Buck%E2%80%93boost_converter


Single-ended primary-inductor converter
http://en.wikipedia.org/wiki/SEPIC_converter


Switch Mode Power Supplies
http://schmidt-walter.eit.h-da.de/snt/snt_eng/snte_pdf.html

Design of Switch Mode Power Supplies
http://schmidt-walter.eit.h-da.de/smps_e/smps_e.html

A New Approach for High Efficiency Buck-Boost
DC/DC Converters Using Series Compensation
http://pelab.nagaokaut.ac.jp/itohlab/paper/20/pesc/fujii.pdf

AVR450: Battery Charger for SLA, NiCd, NiMH and Li-Ion Batteries
http://www.atmel.com/Images/doc1659.pdf
http://www.atmel.com/Images/avr450.zip


Voltage boost and buck circuits using Atmel AVR Tiny13V for driving a white LED.
http://kd1jv.qrpradio.com/tiny13switcher.pdf


283  Using Arduino / Project Guidance / Re: Knight rider light bar with lcd bar graph on: June 30, 2012, 10:40:24 pm
SSD1306 from adafruit.com is not LCD that used in LiquidCrystal Libraries which using HD44780.

You can download our SSD1306 OLED display Arduino library from github
and follow the example
284  Using Arduino / Project Guidance / Re: Knight rider light bar with lcd bar graph on: June 30, 2012, 08:19:35 pm
Here are example of the merge code.
Code:
#include <LiquidCrystal.h>
#include <LcdBarGraph.h>

/*
The circuit:
 * LCD RS pin to digital pin 13
 * LCD Enable pin to digital pin 12
 * LCD D4 pin to digital pin 11
 * LCD D5 pin to digital pin 10
 * LCD D6 pin to digital pin 9
 * LCD D7 pin to digital pin 8
 * LCD R/W pin to ground
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)
*/

byte lcdNumCols = 16; // -- number of columns in the LCD
// byte sensorPin = 0; // -- value for this example
int sensorPin = A0; // select the input pin for the potentiometer
//int ledPin = 13; // select the pin for the LED
int sensorValue = 0; // variable to store the value coming from the sensor

LiquidCrystal lcd(13, 12, 11, 10, 9, 8); // -- creating LCD instance
LcdBarGraph lbg(&lcd, lcdNumCols);  // -- creating

void setup(){
  // -- initializing the LCD
  lcd.begin(2, lcdNumCols);
  lcd.clear();
  // -- do some delay: some time I've got broken visualization
  delay(100);
pinMode(6, OUTPUT);
pinMode(5, OUTPUT);
pinMode(4, OUTPUT);
pinMode(3, OUTPUT);
pinMode(2, OUTPUT);
pinMode(1, OUTPUT);
pinMode(0, OUTPUT);

}


void loop()
{
  // -- draw bar graph from the analog value readed
  lbg.drawValue( analogRead(sensorPin), 1024);
  // -- do some delay: frequent draw may cause broken visualization
  delay(100);
sensorValue = analogRead(sensorPin);
digitalWrite(3, HIGH);
delay(sensorValue);
sensorValue = analogRead(sensorPin);
digitalWrite(3, LOW);
digitalWrite(4, HIGH);
digitalWrite(2, HIGH);
delay(sensorValue);
sensorValue = analogRead(sensorPin);
digitalWrite(4, LOW);
digitalWrite(2, LOW);
digitalWrite(5, HIGH);
digitalWrite(1, HIGH);
delay(sensorValue);
sensorValue = analogRead(sensorPin);
digitalWrite(5, LOW);
digitalWrite(1, LOW);
digitalWrite(6, HIGH);
digitalWrite(0, HIGH);
delay(sensorValue);
sensorValue = analogRead(sensorPin);
digitalWrite(6, LOW);
digitalWrite(0, LOW);
digitalWrite(1, HIGH);
digitalWrite(5, HIGH);
delay(sensorValue);
sensorValue = analogRead(sensorPin);
digitalWrite(1, LOW);
digitalWrite(5, LOW);
digitalWrite(2, HIGH);
digitalWrite(4, HIGH);
delay(sensorValue);
sensorValue = analogRead(sensorPin);
digitalWrite(2, LOW);
digitalWrite(4, LOW);
}
285  Using Arduino / Project Guidance / Re: Self power control using a battery, voltage regulator and transistor on: June 12, 2012, 09:53:11 am
How do you connect the collector of the transistor?
For AVR to control the transistor, the emitter had to connected to ground or 0V of the AVR, then how you control the supply to the AVR?
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