I think teensy has a board with MIDI driver embedded

This thread is about MIDI
Please don't add unrelevant information

I have no idea what the problem was so I started over and used 2 optocouplers and it all works now

Thanks alot for the help! 

Looks interesting
Might try it sometime

So I have set 13 to output and even added some serial output
It still works for some reason

I don't think you should be using digitalRead() on a pin that's an OUTPUT.

It's perfectly acceptable.

Reading a pin configured as an OUTPUT will return the last state set by digitalWrite().

Umm, but this isn't what I want, and it doesn't do that actually
It will return low if connected to the external circuit
And high when disconnected

This seems to work fine
Am I doing this right?

Code:

#define epin 4

void setup(){
  pinMode(epin, OUTPUT);

  digitalWrite(epin, HIGH);
}

void loop(){
  // If the LED on pin 13 is on, it meens that the connection was broken
  digitalWrite(13, digitalRead(epin));
 
  delay(15);
}

This seems to work nicely but the wire pin gives just a little bit of current
I'm using a 2N4401 transistor for the external device and its needs more current

Hi,

I'm making a bomb prop with an external trigger connection
The connection will get a constant 5V power supply so if it's disconnected, the external circuit knows that, and detonates the smoke bomb or what ever
But I also want that the bomb will "explode"

So the Arduino will have the external trigger connected on a digital pin configured to output
An I want it to connect SOMEHOW to an input pin so I'll know when it's disconnected

How can this be done?

Thanks!

The driver is a plastic case with the top face open, which is filled with resin
So how come it's still vibrating?

I bought an EL sheet and driver, but when I power them, the driver beeps
It's logical because the driver is AC, I guess

But is there any way to silence the beep, or are there silent drivers out there?

These: Low-41 High-D9 Ext-FF

I it possible I will have to replace the 16 mhz crystal with a 8 mhz one?

Hi,

I used some ISP programmer, and re-programmed the fuses on some Arduino UNO's (on the usb 8u2 chip)
One doesn't enable uploading sketches, and others just don't communicate over serial.
For some reason, ISP programming is no longer working also.

I read that one can use a crystal to "revive" the mcu, so I bought some crystals, but I'm not sure what should I do now.

So where do I plug in the fuses?

As mentioned here: http://arduino.cc/forum/index.php?topic=119557.new;topicseen#new
The Leonardo needs different RTS & DTR values.

I tried to contact the Arduino team but no answer for a whole month!
I sent another e-mail at September 25th both to the support team and a support team member which answered me before,
but still no answer...

What can I do know?
Is there another way to contact support?