I'm using a 12V battery to power a 12V WS2811 addressable LED strip. I am breaking the GND line of the LED strip feed with a MOSFET. The MOSTET and the addressing of the LED strip is done with an Arduino Mega. The Mega would go broken at 12V, so a 5V voltage stabilizer adds stabilized 5V power.
It's works perfectly well by default. I can change the LED Strip color, brightness, etc. The problem starts when I turn it off. So I set the MOSTFET low, it turns off and breaks the GND line of the LED strip.
Unfortunately, the LED strip then starts to glow dimly, and I measure 6-7 V on the GND and VCC legs of the LED strip itself, so that the MOSFET has broken the GND leg of the power supply.
Since the GND is disconnected, the circuit can only close on the arduino's control output. it is leaking back there for some reason....
The strip is using the Arduino output as ground. It happens because the strip has no other ground. The current flowing through the Arduino pin could easily damage it. So do not do this.
I'm am the kind of person who doesn't look for a solution to a problem that does not exist. There are enough real problems in the world to keep me occupied.
You should consider either just turn the lights off (dark). The power consumption will be really really low, especially compared to the mega I guess that will continue working
Or else change the MOSFET you choose for a canal P instead of a canal N. This way you will be able to cut the power of the LED strip. This implies to change the schematics ofc.
It there a specific reason why you chose to cut the GND in the first place?
If you don't like working with transistor, a relay would work the same. You will juste have a 'click' at each comutation. Or you can use a SSR that doesn't make any noise. If you choose a SSR, careful to choose as DC-DC one. For the classic relay it doens't matter juste take car to choose a relay working in 5V and that can let through enough current
If you need to design a circuit... if you need to badger other people into designing a circuit... "simple" is not the right choice of words.
These people are gathering information, rather than suggesting a solution that you immediately dismiss because of some information you intentionally withheld to cause confrontation. The gathered information helps indicate solutions.
Use an ON/OFF switch. That works for 99.9% of the world. Very "simple."
High-Side switch not an option unfortunately. I would have to modify the drawing too much, or I don't know how to supply the 12V control to it. For Arduino, therefore, they usually do the GND low side switch.
The problem is caused, according to several people, by the circuit being complete on the arudino control cable because of the broken GND. So I would need to make that leg of the arduino to be output only. Maybe if I put a diode there?
Not sure it's a good idea. A diode needs a minimal current to be stable. It can be a small current but the one flowing into the input on the led strip is reallyyyyy low.
In addition, the diode needs to be fast enough for the commutation (I don't know the frequency of the signal). Eventually, the diode will provoke a voltage drop, which could make the communication not working anymore
As suggested, you could remove the 330 Ohms (and then the 220 Ohms) resistor to be sure to understand where is going the current.
