Arduino RGB strip controller switching problem.

[RynoEls]

Hi

I'm having a bit of a problem with a project I'm working on that consist of a Arduino chip(ATMegA 328p), mosfets and RGB strip(1m).

I also built a power supply with an output of 12v and 5v to power the RGB strip and Arduino chip using a transformer with split secondary coils(17v-0v-17v) with 2Amp rating.
(attached you will find and shematic of the whole circuit.)

The power supply is working fully powering the arduino and RGB strip just fine.
The MAIN PROBLEM I've been struggling for days is that when my arduino chip pulses the gate of the mosfets it opens up the gate and switches the rgb strip on ,but the strip wont change color as i anticipated and if i remove the chips output pin from the gate the specific color still stays on even thou there is nothing connected to the gate.

I've done extensive research and still could not get it right.
(attached you will find the mosfets I've used datasheets)

main goal of the project is to be able to control the strip through bluetooth via module that is addd to the chip but i cant move on before the rgb strip can successfully change color.

IM also busy designing PCB so i cant get it printed before everything isnt working fully on breadboard
(attached you will find PCB schematic)


ANY HELP WOULD BE APPRECIATED!
PS. Keep in mind this is one of my first projects
im still a noob.

 

[Bluejets]

I don't see any caps on the crystal, usually around 22pf from each leg to ground.
Also noise filtering cap on the chip itself.

Probably best to break the circuit down into individual bits and get each working first otherwise it becomes a big chunk of problem with no idea where to start.

 

[BobK]

There is nothing to make the R, G and B inputs of the strips high. Turning the MOSFETs on will make it low. Turning them off will do nothing. You need a pullup resistor on each output.

Bob

 

[Bluejets]

I can see a 12v regulator feeding the strips ....???

 

[Audioguru]

Why do you show the datasheet for the IRFZ44 Mosfet that might barely turn on when the gate-source voltage is only 5V? The IRL3705 is fine since it is 'logic level".

A Mosfet has a high gate-source capacitance and no gate current so when it is turned on and the gate is disconnected then it keeps conducting.

The grounds of the 12V and 5V regulators are not connected together.

 

[RynoEls]

I don't see any caps on the crystal, usually around 22pf from each leg to ground.
Also noise filtering cap on the chip itself.

Probably best to break the circuit down into individual bits and get each working first otherwise it becomes a big chunk of problem with no idea where to start.

Hi
Thanks for the reply.

I had caps on the crystal from both legs to ground but then my chip would not work at all.

Sorry but what do you mean by filtering cap on chip itself?

i will start breaking up the circuit tonight and test in bits.

 

[RynoEls]

Why do you show the datasheet for the IRFZ44 Mosfet that might barely turn on when the gate-source voltage is only 5V? The IRL3705 is fine since it is 'logic level".

A Mosfet has a high gate-source capacitance and no gate current so when it is turned on and the gate is disconnected then it keeps conducting.

The grounds of the 12V and 5V regulators are not connected together.

Hi
thanks for the reply.

I am very inexperience when it comes to working with mosfets , i have only done researches in to mosfets.

Thanks for the information.

I will change that and connect the grounds all together.

 

[RynoEls]

I can see a 12v regulator feeding the strips ....???

Hi

Can you please give more information on what you are trying to state

thanks

 

[RynoEls]

There is nothing to make the R, G and B inputs of the strips high. Turning the MOSFETs on will make it low. Turning them off will do nothing. You need a pullup resistor on each output.

Bob

Hi are you saying i need to add a pullup resistor on my gate of the mosfet/output of chip?

 

[Bluejets]

You appear to be having several basic problems and no understanding of why so it might be a good move for you to just start with an Arduino Nano for maybe $5.00 which has all the necessary micro bits ready to go at least and then progress to your own board building further down the track.

 

[BobK]

Hi are you saying i need to add a pullup resistor on my gate of the mosfet/output of chip?

Never mind. I misinterpreted the schematic. These are the grounds of a common anode LED. No pullup required.

Bob