24v COB rgb 840 strip controled by Raspberry Pi

My apologies  fskrzycki for my response on using modules solutions to solve problems consuming your post. That was never my intention. 

You being a new member, it does provide an example of the potential the E14 Community provides. You will need to develop the ability to keep from getting upset or offended by the things other people say and do. You have to have a thick skin when it comes to criticism. Most responses are OK but with 700K members there may be some responses that reflect a lack of emotional intelligence.

I remember one of my early forum adventures when I tried to help out a fellow member with my limited knowledge. I suggested a simple solution, and then this person got all fired up and replied, "Some of us solder components!"  My kids still crack up about that post. 

I look on in envy at some of the more advanced techniques members have talked about on the site. I'm happy to have moved from hand drawn PCB's etched in chemicals to KiCAD documents used to manufacture quality PCB's. The tax and duty kills me!

I think about doing SMD but for the small projects I attempt through-hole works. Call me old school, that is OK.

Many of careers involved defining requirements. It helps separate the I want from the I needs. Sometimes what you are required to do is not what you want to do. I do value the E14 Community as a knowledge resource. I get some confidence from tapping into others experience instead of going it alone.

i planned on making a custom PCB. Im i misunderstanding The GPIO layout on my Raspi 4b. i see pin 2&4 are 5v?

There is a link for that.

 Raspberry Pi 4 Model B Default GPIO Pinout with PoE Header 

Questions:  In my current config. I would put the 817 between the Pi and source of my MOSFETS. I think I need to use 3 lines of the optocoupler. 

Could i connect 3 ground wires to the same Raspberry GPIO pin? 

Where would you put 817 in this circuit?

CIRCUIT config.  

LEDs are controled by a common ground and Three separate Data lines. Strip has a 4 pin connector. Power pin is black(24v) + 3 Data GPIO pins RGB. (3.3v)

1: power supply positive straight to strip 

2: RGB MOSFET 1,2,3, drains connected to power supply negative.

3: Pi Data (pins) RGB MOSFET 1,2,3, source 

4: RGB MOSFET 1,2,3, Gate connected to LED Strip

I am using 1 ground pin from the Pi  connected straight to the breadboard power supply ground

Questions:  In my current config. I would put the 817 between the Pi and source of my MOSFETS. I think I need to use 3 lines of the optocoupler. 

Could i connect 3 ground wires to the same Raspberry GPIO pin? 

Where would you put 817 in this circuit?

CIRCUIT config.  

LEDs are controled by a common ground and Three separate Data lines. Strip has a 4 pin connector. Power pin is black(24v) + 3 Data GPIO pins RGB. (3.3v)

1: power supply positive straight to strip 

2: RGB MOSFET 1,2,3, drains connected to power supply negative.

3: Pi Data (pins) RGB MOSFET 1,2,3, source 

4: RGB MOSFET 1,2,3, Gate connected to LED Strip

I am using 1 ground pin from the Pi  connected straight to the breadboard power supply ground

Hi,

This needs a diagram. There are inconsistencies, and I cannot tell if they are typos or not. For instance, this part:

"LEDs are controlled by a common ground" doesn't sit with "Power pin is black(24v)". Can you sketch a quick diagram showing what you mean? In other words, a circuit diagram showing all of the current config, and the MOSFET part code (or web link) so it's all clear what you've got.

I have to agree with  shabaz this project needs a schematic.

You can hand bomb a drawing like the example provided or use a program like KiCAD or Frtizing.  

 fskrzycki  Nope! you will lose your galvanic isolation between the Pi and the 817  The Pi ground only goes to the 817 input grounds. The Output grounds and the MOSFET grounds must be ISOLATED FROM THE PI. I am making an assumption that you have two (2) power supplies. DO NOT TIE THE GROUNDS TOGETHER. you could end up with a very bad day! like losing your Pi. ~~ Cris H. 

i am little confused because the 817 needs Two inputs, 1 Ground & 1 Data. with this set up, the voltage spikes are leaking through the MOSFETs

There's no detail in the diagram, somehow it has been inserted as a tiny image.

Could you upload the diagram using the Insert menu item, then select "Image/video/file", and then you'll be able to choose the image file.

Currently, the image looks like this zoomed in:

Also, what is the part code (or web link) of the MOSFETs? A photo of the setup will help too.

That helps a lot. Based on that, if the circuit so far is successfully operational, then the LED strip is known as common anode (not common ground), which helps understand the circuit.

The circuit below shows how to insert the PC817. Notice that the Pi's GND is completely isolated from the 0V connection which will be connected to your LED strip's power supply brick.

With the PC817, the output will be inverted, i.e. you'll have to set the GPIO high to turn off the LED and vice-versa. There's no clean way around that, without changing the design, or inserting more parts (refer to the earlier diagrams to see how that is done). Rather than that, it should be a trivial change to edit the Python code to invert the logic.

Every component in the diagram below is essential. If you're using a PC817 module (as opposed to just the PC817 component) then, as discussed earlier, the module has some issues. You'd need to remove the LEDs on the PC817 board, and you'd need to replace the 1k resistor on the board with 220 ohms as shown in the sketch here. It would be easier to just buy the PC817 component and not the module, but modifying the module as mentioned would fix it.

i understand. Just to be clear the circuit above is for one color only.. if I go with using the 817 component, can I use the same gpio ground pin for each color? 

Can the overvoltage protection be the same component in the example above? I think you have the Gate/Source/Drain on the MOSFET mislabeled. can you double check