teensy to matrix board with 400 ucs1903 ledstring output destroyed teensy ???

Status
Not open for further replies.
N

nikkilauda

Well-known member
Hi i have 400 leds ucs 1903 directly hooked up to my teebsy output 6, with a test of 21 leds everything works, when i hooked up 400 leds my teensy gets hottee then hot now no connection between my teensy anymore think its gone.

Is it wring to just connect the 400 leds to the teense pwm output ?
Did i had to instal a pul up/down resistor or did i had to install a driver or a relais ???

I fed the leds with a 5v supply the teensy too, so the teensy does nothing more then give a data signal to the board ???

The output is 40 ma of the teensy ore did it take power from the leds i can buy a new ine but have to solve the problem first.

I did connect a 245 buffer ic to the output to increase the 3,2 v from teensy to 5v.

Help what is wrong ??
 
Others can answer this much better than I can, but might help to see picture of hooks ups or at least a diagram.

If you disconnect everything from the Teensy, except USB can you program it and run something like blink?

Do you have a mutli-meter? Can you measure the resistance from Pin 6 to GND? Likewise between power and ground of your LEDS...
 
Everything worked great blink leds,,but now i cant even get it to connect with usb, and it gets hot.
i did not reverserd the polarity.

How can it be distroyed ? Ore check it
 
Yess i have a + and a gnd and treu a buffer ic to pin 6 and 4,36 V to the teensy what can blow up my teensy ?
With 21 leds it worked connected it to 400 leds (long wires) teensy gets hot and no communication with the laptop.

Hooked up the 21 leds same isseu so teensy lookes smoked.

Already orderd a new one but how can i prevend it to happen again ?
 
nikkilauda said:
but how can i prevend it to happen again ?
Click to expand...

Impossible to know exactly what went wrong. We can not see what you actually did. No diagrams, no photos, etc. All we know is the info you write here, which basically says you believe you connected the wires properly. How could anyone tell?

However, there is a common practice of using 100 to 330 ohm resistors between the buffer chip and the LEDs. The resistors can help with noise. If things go very wrong, sometimes the resistors can limit the current enough to prevent damage. Impossible to know if these would have helped, but they're a good idea anyway.

Another thing that can help is powering the LEDs from a power supply and the Teensy from USB power. You still must connect their grounds together, but not the +5V power pins. Using only the ground connection tends to prevent ways for a huge amount of power to flow if things get connected wrong. Again, impossible to know if that would have saved your board, but it might be worth trying for the next one.

Also worth trying would be some quick photos of how you're actually doing things. If you need help here, photos can make the difference between blind guessing and someone noticing something you overlooked. Even if you don't post any here, photos can also really help you later, to know how you did things.
 
Yes thats the problem i wired the teensy with usb and the 5V supply from the leds, it stays 5 V but the teensy gets the current of the leds true the usb from the usb com port.

So i can hook up the negative from the powersupply but not the 5 V ?
And wich resistor between the buffer ic and the leds ?
 
Hello everybody,
I also cannot tell what went wrong with your setup, nikkilauda, but as Paul already said, it is always a good idea to put resistors in between and also, thats my advise, a condenser between the plus and minus on the wire that goes to the LEDs. There are hundreds of websites that come with this advise as well. If you don't know about the "how", the "what" and "why", let me link you to
learn.adafruit.com
They have a tutorial about just everything related to this topic.
I myself actually learned a lot following their tutorials.

Good luck!
:)
 
I even got fuses between the posersupply and leds no reistor.
So a condenser between the negative and possitive of the power supply ?
The resistor between my data from teensy to the leds
 
Fuses rarely prevent electronics from being damaged. Their main purpose is to prevent burning which can start a fire. By the time a fuse blows, things have usually gone so wrong that the electronics are already dead.
 
So i atach a 330 ohm resistor onport 6 that to data-in from my ledstring, teensy to usb, the ledstring to powersupply, and the buffer-ic no further safety for the port 6 and the great current fron the leds.
 
Status
Not open for further replies.
Back
Top