SOLVED Muzzle LED hates me (question about bi-color LEDs)

[Danbieranowski]

Built a properly working Muzzle (from an audio standpoint), but the LED doesn't light up. I had to sub the 5k6 resistors for 5k1 bc it was the nearest value I had on hand. Is this too low and it's just killing the LED? I've never used bi-color before so I'm not sure if they behave differently.

I'm using these common cathode LEDs from Small Bear: https://smallbear-electronics.mybigcommerce.com/led-5mm-bi-color-diffused-water-clear/
So the LEDs shouldn't be a problem.

Not uploading pictures and such yet, as the whole pedal works other than just the LED (I've tried two now so I don't think it's a bad LED).

Is it possible to use this pedal with a single LED without the "gating" being shown (just as a test)?

Anyways, I'm just full of questions today! Party on ya'll.

Link to Muzzle build doc: https://docs.pedalpcb.com/project/PedalPCB-Muzzle-Classic.pdf

 

[PJS]

I haven't used bi-colour LEDs, but I have done a bit of work with RGB ones, and there can be some variation in the pinouts. I would double check that the one you got matches the PCB design.

 

[PJS]

Oh yeah, if you have a multimeter that will do a diode test then you can use it to work out the pine, whether it works or not, and what the voltage drop is. With the -ve lead on the cathode and the +ve lead on anode the LED will light and the meter will tell you the voltage drop. I have never damaged an LED like this. I have done this before to match (actually unmatch) LEDs for clippers on distortions.

 

[Mcknib]

Check what voltage you get on the anode pins

The common centre pin is ground and the 2 outer pins + volts as you know double check you're actually getting a voltage on them

I have had bi colour LEDs where the common pin hasn't been what I ordered

The easiest way to check it is common cathode is using your meters diode check

Place ground probe on the centre pin and red probe to either outer pin and it should light confirming it is common cathode

 

[Vildhjuggah]

which bezel did you use?/are you testing outside or in box?
cuz if you are using a metal bezel it could be shorting it
also i imagine putting a led on just one side should work fine

 

[Danbieranowski]

Check what voltage you get on the anode pins

The common centre pin is ground and the 2 outer pins + volts as you know double check you're actually getting a voltage on them

I have had bi colour LEDs where the common pin hasn't been what I ordered

The easiest way to check it is common cathode is using your meters diode check

Place ground probe on the centre pin and red probe to either outer pin and it should light confirming it is common cathode

You were absolutely right. While this is labeled as "common cathode" on the Small Bear site, it is actually common anode, as each side only lights if I put the red probe on the center pin and ground on the outers. I should have known how to test this, but in my frustration I wasn't thinking straight lol. I thought I was losing it. Anyways, thanks as always.

 

[Mcknib]

I wasn't thinking straight lol. I thought I was losing it. Anyways, thanks as always.

Haha I've been at it a long time and still overlook stuff that's staring me right in the face

All part of building yer own! sometimes it's unforgiving

I don't know how many times I've given myself a severe slap for not doing something I knew I should have

Anyway Steve will sort you out I'm sure, he's one of the original goodfellas

 

[Danbieranowski]

Haha I've been at it a long time and still overlook stuff that's staring me right in the face

All part of building yer own! sometimes it's unforgiving

I don't know how many times I've given myself a severe slap for not doing something I knew I should have

Anyway Steve will sort you out I'm sure, he's one of the original goodfellas

View attachment 6704

The fact that common cathode and common anode bi-color LEDs exist is the real crime here! Pick a format, LED manufacturers!

 

[Mcknib]

The fact that common cathode and common anode bi-color LEDs exist is the real crime here! Pick a format, LED manufacturers!

I blame @PedalPCB I mean who uses common cathode these days eh? Even if the original did, you just don't, do you?

 

[peachsoju]

I blame @PedalPCB I mean who uses common cathode these days eh? Even if the original did, you just don't, do you?

I really wished PedalPCB would adopt the system of detailed BOM with detailed instructions that AionFX uses. I have all the info I need when doing AION stuff. With PedalPCB and PCBguitarMania, there is still plenty of guess work and figuring. AION would have put the LED exact part number to get and where to get it in their instructions and possible an alternative for those of us who are red green colorblind.