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301  Using Arduino / Installation & Troubleshooting / Re: Basic problem with analogRead() on: April 24, 2014, 04:43:53 pm
The suggestion to short them to ground is to prove that floating condition was indeed causing readings with no input connected.
Connect then input to an analog sensor with an output between 0 and 5 volts to get your readings.
Do not leave the analog input floating else you will see some sort of signal when you expect to see none.
302  Using Arduino / General Electronics / Re: surface mount 1N4007 options? on: April 22, 2014, 11:32:52 pm
I just use a 1N4007 and bend the leads down and cut them short.
OR see
http://www.sycelectronica.com.ar/semiconductores/1N4007-SMD.pdf
303  Using Arduino / General Electronics / Re: Negative voltage driving LEDs -- how to amplify/distribute? on: April 21, 2014, 11:23:53 am
Good for you for hanging in there.
Beware of friends that have epilepsy using this.

304  Using Arduino / General Electronics / Re: regulator problem !!! please help on: April 20, 2014, 08:30:00 pm
Quote
i was using my arduino uno and suddenly it turns off !!

So it was working with the batteries, something happened, now it does not work?
It still works with the USB cable only?
305  Using Arduino / Programming Questions / Re: if not working on: April 20, 2014, 08:24:49 pm
Tell us a bit more of the what you are trying to do here?
306  Using Arduino / General Electronics / Re: regulator problem !!! please help on: April 20, 2014, 08:18:50 pm
Do you measure 8 volts across the batteries when there are plugged into the Arduino power jack?
307  Using Arduino / Programming Questions / Re: Set LED Brightness as a subroutine on: April 20, 2014, 08:15:23 pm
Yes learn how to use BlinkWithoutDelay

Here is an example, do you understand how it works?
Code:

const unsigned long TaskAtime  = 500UL;   //Runs TaskA every 500 milli seconds
const unsigned long TaskBtime  = 60000UL; //Runs TaskB every 60 seconds

unsigned long TimeA;                      //Times up, Task A time
unsigned long TimeB;                      //Times up, Task B time

//==========================================================
void setup()
{
  TimeA = millis();                      //Initailize 
  TimeB = TimeA;                         //Initialize

} //        >>>>>>>>>>>>>> END OF setup() <<<<<<<<<<<<<<<<<

void loop()
{
  unsigned long millisNow = millis();

  //==================
  if (millisNow - TimeA >= TaskAtime) //Is it time to run Task A?
  {
    TimeA = millis();                 //Re-initialize
    TaskA();
  }

  //==================
  if (millisNow - TimeB >= TaskBtime) //Is it time to run Task B?
  {
    TimeB = millis();                 //Re-initialize
    TaskB();
  } 

  //Other stuff goes here


} //        >>>>>>>>>>>>>> END OF loop() <<<<<<<<<<<<<<<<<


// FUNCTIONS
//==========================================================

void TaskA()
{
   // TaskA code stuff goes here
}

//==================
void TaskB()
{
  // TaskB code stuff goes here
}

//==================

308  Using Arduino / General Electronics / Re: regulator problem !!! please help on: April 20, 2014, 07:59:20 pm
serial 6 AA battery
What does this mean?
309  Using Arduino / General Electronics / Re: Negative voltage driving LEDs -- how to amplify/distribute? on: April 20, 2014, 05:06:13 pm
Let us know how it works.
310  Using Arduino / General Electronics / Re: Negative voltage driving LEDs -- how to amplify/distribute? on: April 20, 2014, 12:21:46 pm
The opto isolator transistor turns on/off as it's led goes on/off.
With +5 volts on the opto's transistor  collector you need a ground path for current to flow.
The input resistance of the FET is ideally infinite hence there is no ground path through the gate to source to ground.
Adding a 4.7K from the emitter to 0 volts gives you the needed ground path.

Hence, when the transistor is on the emitter will be at +5 volt turning the FET on (O/P LEDs will be on).
When the transistor is off, the emitter is at 0 volts through the 4.7K and the FET will be off (O/P LEDs will be off).

If the original glasses LEDs were on with a negative o/p on the plug, using your opto isolator circuit will do the same thing.

311  Using Arduino / Microcontrollers / Re: ATmega644p reboots on serial input on: April 20, 2014, 11:04:14 am
Can you confirm the power from the FTDI is not dipping?
312  Using Arduino / Microcontrollers / Re: ATmega644p reboots on serial input on: April 20, 2014, 11:02:15 am
Place some 100nF capacitors from the pins connected to VCC to GND. Ex pin 10 to GND, 32 and 30.
313  Using Arduino / General Electronics / Re: Negative voltage driving LEDs -- how to amplify/distribute? on: April 20, 2014, 10:10:18 am
If you are making new glasses then I guess you can reinvent the wheel.
314  Using Arduino / General Electronics / Re: Negative voltage driving LEDs -- how to amplify/distribute? on: April 20, 2014, 10:03:48 am
@Paul__B yes it would invert.
@ joshuabardwell
I like that.
A 4.7K resistor from emitter to ground is needed.
A 4N35 with >100% CTR would be recommended.
If you need to sharpen the edges for some reason, turn on timing for FET, then select an appropriate base to ground resistor (pin 6) can be added.

315  Using Arduino / General Electronics / Re: Negative voltage driving LEDs -- how to amplify/distribute? on: April 20, 2014, 12:40:21 am
I was thinking something like this but it's 11:50 and time dream on it.
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