Nucleo Leds are too bright

[gregstm]

Is there a prize for the most trivial post?

Opened up a new Nucleo-L476RG board (finally worked my way through the 10+ boards I bought a number of years ago) - it comes in a cardboard box now, nice.

The Leds (LD1, LD3) were so bright, I couldn't probe anywhere around the micro or connectors without squinting. So I replaced the resistors for these Leds (1K, 100?) with 22K, things are much more mellow now.

Most people are using these boards indoors, the Leds only have to be bright enough for people to notice - not beaming out like the Eye of Sauron. 

Anyway, something for you to think about. Meanwhile, there's a few annoying clouds outside I need to shout at....

[David Littell]

What, you don't do all your debugging while wearing a welder's helmet?  Safety first!

[Mike_ST]

Hello,

Thank you for your feedback.

What board revision do you have ?

It should be something like "MB1136-C02" written on a sticker on the back of the board.

[David Littell]

Every single Nucleo I've ever used has had insanely bright LED's, so I'm not sure a specific revision of a specific board really matters.  Just sayin'.

[Andrew Neil]

I thoroughly agree!

That's why I have a sticker on the LED of this Nucleo ST-Link:

@Mike_ST  -  As @David Littell said, it's always been thus - not specific to any particular model or revision.

To be fair, this is not just an ST thing - most electronics manufacturers seem to be on some sort of bizarre competition to have their LEDs (especially blue ones) out-shine the sun!

[LCE]

The ST developers are working in sunny lofts and penthouses, always close to the italian or french beaches, so they wearing sunglasses anyway!

;)

We recently had the same problem with a board with some internal debugging-only green LEDs in 0603 + 1k to 3.3V.
I never specified these in the BOM, so the assembler should just use what they got (low numbers, highly priced product :D ).
Worked well for years, but recently they mounted some new crazy bright LED which was even with 10k brighter than anything we've seen before.

I haven't used a Nucleo for some time now, but yeah, the red link-LED was always on the bright side (whistle!), maybe they even changed the LED type?

[Mike_ST]

>> Mike_ST  -  As David Littell said, it's always been thus - not specific to any particular model or revision.

Noted. As I use the boards myself, I understand.

I will raise the point internally.

It will not change the boards already produced, but hopefully for the future designs.

[Ozone]

I tend to agree as well. Really annoying if you want to measure something on the board.

One suggestion is to use a permanent marker  (of you favourite color) to paint onto the LED to dim it down.
Or use something like frog tape (adhesive tape used for painting), which is somewhat semi-transparent, so you can still see the light.

[Mike_ST]

>> I never specified these in the BOM, so the assembler should just use what they got (low numbers, highly priced product :D ).
>> Worked well for years, but recently they mounted some new crazy bright LED which was even with 10k brighter than anything we've seen before.

So, you know well what is happening.

LEDs have evolved in efficiency. Setting 10mA for a LED might be not so relevant nowadays.

[Andrew Neil]

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@Ozone wrote:

Or use something like frog tape (adhesive tape used for painting), which is somewhat semi-transparent, so you can still see the light.

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Indeed - see my earlier comment!