Hello, I am working on my first layout and wanted to put some LED's in a building. I hooked up 7 LED's (warm white) to an adafruit TLC 5947 (which is a 24-channel PWM/LED driver) which was then hooked up to an Arduino Uno R3. I tried to get the program to run that I was trying to, but it wouldn't and now my LED's stopped working. I have used a multi-meter to test for continuity, with 6 doing nothing and one that buzzed. I have more of the LED's which I have soldered on longer leads to the original leads. When I tested these, there was no buzzing, instead the LED came on. So I am really confused on if I am testing them right. can someone help please.
thanks
Just an educated guess here, but it sounds like you may have smoked the LEDs.
What is the buzzing you're referring to? I've never had a multimeter that buzzes.
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
A cheapo multimeter such as the Harbor Freight The HF meter will illuminate an LED enough to see a glow using the lowest resistance scale. That is my quickie way of checking LEDs.It is best to use a current limiting series resistor even in low voltage circuits like Arduinos. I would go with a 470Ω resistor operating at 5 volts. That will limit the current to under 10ma, 1000Ω resistor for 12 volts.I rarely operate my LEDs at max current (20ma). I find them most realistic looking operating under 5ma. My passenger car lighting uses under 1ma per LED, a string of 8 warm white LEDs draw a total of about 2ma for the most realistic lighting.There are a total of 12 LEDs in my lounge car totaling 2ma.Eight LEDs attached to the ceiling and four table lamps total 2ma.Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
equake9, Welcome to the forum!
Your first posts are moderated and probably won't show up immediately, but if you keep posting, that will clear up quickly.
Let us know more about your layout. There are a lot of experts on this forum who can help with just about any problem.
Did you have any resistors with the LEDs when you tried lighting them?
Pruitthat is the buzzing you're referring to? I've never had a multimeter that buzzes.
My $9.00 multimeter has a continuity setting that will buzz or play a tone when a circuit is connected. I find it helpful when testing lots of connections.
York1 John
Even when just doing continuity testing, a LED is still a diode. It will show continuity in one direction, but if you reverse the leads, it will look like an open circuit.
My tester for LEDs is a 9 volt battery and a 1K resistor. Wired correctly, the LED will illuminate. Wired backwards, it will block any current and not illuminate. If it doesn't work in either direction, your LED is now a Darkness Emitting Diode, or DED. The good news is that it won't take up much space in the wastebasket.
It takes an iron man to play with a toy iron horse.
I am an Arduino pre-newbie but don't they put out 5 V?
LED's I've used are rated for 3 V, although there are some rated as 12 V. I am not sure what you are calling a micro LED but some of them are pretty darn small. I'm not sure any of them are rated for more than 3
If yours were 3 V, they are smoked
Henry
COB Potomac & Northern
Shenandoah Valley
Several people have commented on currnet limiting resistors. I don't know what the problem is but I would like to point out that the TLC 5947 is a constant current LED driver so it elminates the need for the current limiting resistors.
Adafruit has some pretty good Learning pages on the TLC 5947.https://learn.adafruit.com/tlc5947-tlc59711-pwm-led-driver-breakout/connecting-to-the-arduinoI’m not into multiple LEDs so I haven’t dug into that, the closest project I have to using the TLC 5947 is my Arduino Random Lighting Controllers.
I always use a limiting resistor because I always set the individual current to each LED manually by eye, most of the time there isn’t room for more than a ⅛ watt resistor.Mel Modeling the early to mid 1950s SP in HO scale since 1951My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California Aging is not for wimps.