Level shifter

What is the correct way to connect a 74hct125?
I also post this in the Dutch forum, but in English there is a larger public.

I use a PI3 and apa102 LEDs. I see a lot of different ways, but no concrete answer for me.
Everything is now connected as discribed on the adafruit forum. But I would still like confirmation before I connect the powersupply.

Adafruit Forum

Showcase @paddy here on the forum.

I want to separate power for the pi because I use a mausberry. Therefore, the lower figure did not seem right for my application.
But I am not sure what the difference is between these versions. If someone can confirm these steps, I will edit the wiki so this will be clear to all.

Almost finished! Work in progress!

Zitat von penfold42

The top breadboard picture is mostly correct. It should work but the unused inputs should be connected to high or low and not left floating.

Thank you for your reply!

I'm not sure what you are saying now. Should I connect the unused input(A4 and A3) pins to ground or to C or Y?

Thank you very much for your help!

I don't want to open other threat as I am not sure if my problem is hardware or software. At first all the leds worked if I set a color with the remote. Then made the gap in the bottom a little bit bigger, as this looks nicer for my setup.

Now there are always 3 leds burning and only the half of the strip works. I also tried another Pi, another IC and checkt all the solder connections (this strip was cut for a smaller tv, so I had to connect in the middle). Still the same effect. There are a few leds in the part that also don't light up. I don't understand the behavior.

Can someone help me to pin point my problem? Below some pictures to clarify.
Apa102

Double post

Zitat von TPmodding

do you have more leds then you use in your config? (example: 100 leds, but only 95 used in the config)

No, I updated the config when I cut the strip. I also tried to play with the config file, but still no luck

I hooked up an Arduino to test the leds and it seems to be a hardware issue. But where to look? I already replaced a "broken" led en then another one will break. I saw some resistors on the strip, why are these? As I cut the strip, I am not sure these are still all in.. And I also don't know how many led there are between them.

No not at the Pi. I got the same effect with the Arduino. So the led must be faulty. I am now replacing all the broken leds and check every time I add a part.

Edit:

Just to follow up on the issue. After replacing the broken leds, everything is working fine. Not sure how the led got broken, but I'm glad it is fixed now.