How do I properly hook up external LEDs I/O board 5.6 XL?

[guzzard]

I have a couple of questions regarding connecting the LEDs externally. Hopefully someone here can give me some guidance.
I looked at github (io board 5.6 pdf) and in various forum posts etc but have trouble understanding how to properly hook up the LEDs.

On the I/O board v. 5.6 XL:

1. P5 jumper seem to control both on-board and external LEDs? PDF indicate they control only the on-board LEDs. When removed I get no voltage on external pins (except disk 0,7v?). Is there a way to turn off the on-board LEDs in the ini-file? I have not found any such option.

2. With P5 jumper connected when LEDs are OFF I get between 1,4v - 1,8v on the external pins, and when they are ON I get zero volt. This seems low as well as inverted? I was expecting 3,3v when LED is on and 0v when LED is off? Can anyone clue me in on what's going on here, and how to hook this up properly?

[guzzard]

For anyone else wondering..

1. P5 jumper functions as expected when connecting LEDs as shown below.

2. Connected LEDs as shown below and this works fine for me. This is based on other user posted images and various forum posts. I don't know if there is any official guide or information about this? I have searched but have not been able to find any official guide or info on the external LEDs or external buttons.

External LEDs.png (221.91 KiB) Viewed 15313 times

[legacypixels]

The LED signals are active low. The LEDs are always powered, and "turned on" by providing the ground.

[guzzard]

The LED signals are active low. The LEDs are always powered, and "turned on" by providing the ground.

When LED is off both plus and minus are at 5 V, so the potential difference is 0 V, and then LED is activated by dropping the voltage on minus to around 1.7 V making the potential difference around 3,3 V.

If I understand correctly this is what you mean as well?

[Geords]

Hi, Guzzard.

Just wondering which pins you're measuring 1.7v between? Are you measuring the voltage between the 5v pin (pin 1?) and the led signal pins (2, 3 and 4)? Or are you measuring against pin six, which looks like it /might/ be ground on your board according to the schematics? Warning: I'm not very good at reading those.

Apologies if the XL is different to the normal 5.6? https://github.com/MiSTer-devel/Hardwar ... rd_5.6.pdf

[guzzard]

Hi, Guzzard.

Just wondering which pins you're measuring 1.7v between? Are you measuring the voltage between the 5v pin (pin 1?) and the led signal pins (2, 3 and 4)? Or are you measuring against pin six, which looks like it /might/ be ground on your board according to the schematics? Warning: I'm not very good at reading those.

Apologies if the XL is different to the normal 5.6? https://github.com/MiSTer-devel/Hardwar ... rd_5.6.pdf

Yes, it was between ground and pins 2,3,4.

[Geords]

Yeah that must be a thing with analog boards. Neil on RMC youtube channel was building a desktop mister in a checkmate case and mentioned what sounds like a similar undervolt with an analog io board's led pins.

Around 7m50s
https://youtu.be/JGXZgVLh02Y

So the led pins are 5v off and of 1.7v on? I guess that makes sense with the diag above.

The reason I ask is that I'm thinking off swapping out my digital io board for an analog one and wondered if my current hex inverter led set up would work. I'm not sure it will if the led pins are doing 5/1.7v. Nor 1.7/0v for that matter...

Good to know!

[sk8er000]

I tried to connect the external LEDs following the same scheme but no matter if p5 is opened or closed, when I power on the mister the external leds power on at first but then they stay off permanently.
Obviously if p5 is closed the onboard IO board LEDs are working properly otherwise they stay off too.
Am I missing something?

[sk8er000]

Problem solved, I simply misread the pinout so instead of VCC I use gnd now it's working fine

[thisisamigaspeaking]

For anyone else wondering..

1. P5 jumper functions as expected when connecting LEDs as shown below.

2. Connected LEDs as shown below and this works fine for me. This is based on other user posted images and various forum posts. I don't know if there is any official guide or information about this? I have searched but have not been able to find any official guide or info on the external LEDs or external buttons.
External LEDs.png

Sorry to necro this, this is the post that came up on google with a diagram and discussion about it.

Is this diagram correct? I'm having trouble conceptualizing how/why this works.

Let's say I have a 7-pin connector that I want to hook up to a PC HDD LED (on a Checkmate case). I run pin 1 (5V) through a 330 ohm resistor to the positive pin on the LED header, and pin 3 (disk) to the negative pin, and it will be off (1.7V) most of the time then go to 5V when it lights up? The 5V is not live all the time?

Another thing is that on a Checkmate case which I am using there are two places you can connect to the LEDs, "Amiga" and "PC" and it looks like the Amiga side already has resistors? So the PC side must be the stock behavior of PC case LEDs, but I'm not sure what the Amiga side is set up to be. Maybe I should use that side?

In this he decided to just solder directly to the LED on the i/o board which I don't really want to do. Seems like he also didn't understand the need for a resistor when he burned out his LEDs off the 5V.

[thisisamigaspeaking]

Ah, makes sense. So this is correct and what is necessary to understand:

The LED signals are active low. The LEDs are always powered, and "turned on" by providing the ground.

And this is not correct:

When LED is off both plus and minus are at 5 V, so the potential difference is 0 V, and then LED is activated by dropping the voltage on minus to around 1.7 V making the potential difference around 3,3 V.

If I understand correctly this is what you mean as well?

The GND pin for each LED will just be not connected (by the board/DE-10/wherever) when it is not active, right?

Thanks for clarifying, legacypixels (here and in the other thread), I should've noticed that you are an add-on board seller. That is how I would've assumed it worked before seeing this thread. I thought some convoluted scheme was at play here for some reason. Also the advice in that linked video is unfortunate - goes to show you shouldn't always go to youtube for howto videos...