I am currently working on a big school project involving arduino and some sensors, some transistors, 2 8-bit-shift registries(I think it is a 74HC595 but for some reason i can't check the specific page on the arduino store that it was on, to check) and a bunch of leds.
The setup worked completely, but a few days ago 2 of the 14 leds failed(first 1 than the other,not at the same time)
After some measurements I concluded all components work as they should. The Arduino gets signals from the sensors, the other led are working so the 8-bit shift registries can't be to blame, and if i put 5V output to the wire that normally was connected to the 8-bit shift registry the particular leds lighted up. But now after some more measurements I concluded that the 8-bit shift registries didn't give an output to the transistor of the leds that do not work. So my question is:
is it possible that a single pin of an 8-bit shift registry breaks without the whole component breaking?
or should i continue to search in other places for the fault.
Do you have current limit resistors in series with the LEDs?
If you just have HC595 to LED to +5, or Gnd, then it's just a matter of time until some more IO pins go bad.
MarkT:
Yes its perfectly possible if you overload the pin or overvoltage it.
Its "shift-register", not "registry". A register is a collection of flip-flops.
thanks for the answer
I thought it wasn't obligated to contract verbs like that, i thought it was just an option.
ps English is not my native languige.
CrossRoads:
Do you have current limit resistors in series with the LEDs?
If you just have HC595 to LED to +5, or Gnd, then it's just a matter of time until some more IO pins go bad.
The LEDs aren't connected directly with the shift register, there are transistors in between and the LEDs have some resistors in them(yes, I know some kind of weird LEDs but, i got them from my teacher.)
cjdelphi:
595's damage easily .. a little over voltage and I've had them die or just random pins.
So what do you suggest, that i have a few extra so I can swap them out if necessary?
cjdelphi:
I only swap them if they are misbehaving... if that cures the problem bin the faulty one.
I can currently solve the problem by switching the the 2 broken pins ones with the 2 unused ones but I will order new ones because if one more breaks, I'm screwed.
The second is less formal and arguably more appropriate here, but both are equally valid. "It is" is more likely to be used when the author is trying to press a point, eg "It is imperative that you secure the emergency door", as opposed to "It's OK to have a beer after work".
[quote author=Runaway Pancake link=topic=225891.msg1634358#msg1634358 date=1394821241]
And you should have used it's. It's is the contraction of it is.
I thought it wasn't obligated to contract verbs like that, i thought it was just an option.
ps English is not my native languige.
[/quote]
You didn't use (or misuse) its or it's in your post.
I was correcting the corrector. They must be beyond reproach!
You're not "obligated" to contract verbs, but its is a possessive pronoun.
