Beginner hobbyist here. I would appreciate some design feedback.
Purpose of this circuit: It controls an RGB LED strip (5 Meters, SMD 5050) via an IR remote and also automatically powers on/off the LED using an ultrasonic sensor (HC-SR 04). The brain here is the Arduino Nano. The Nano takes input from the IR sensor (TSOP 1738) to determine which color and brightness needs to be output. It uses its PWM pins to control the LED strip via the 3 MOSFETs (IRF3205) which go to each of the 3 color wires of the LED strip. Both the circuit and LED strip are powered by the same power supply ( I confirmed via data sheets that the Nano can be powered by a 12v power supply).
The radio (NRF24L01) module is for this circuit to sync and coordinate with other peers in the room. I plan to have multiple circuits like this powering a stairway. So when someone enters the upstairs/downstairs door, the ultrasound sensor would detect it and let the Nano know to turn on the LEDs, which would in turn pass this on to other Nanos that are further into the stairs but don't have the motion sensor.
I've put in 220 ohm resistors between the MOSFET and Nano because I found that on several circuits and tutorials online. Would help an explanation of what exactly its purpose is and how to calculate the value.
The power supply is from a local bazaar that doesn't seem to have any data sheet or guarantee. I'm almost sure the quality of the DC signal is not great and maybe its not even the 5A it claims. Is there any capacitor filter based circuit I can put in to ensure the circuit receives a) Smooth, clean DC signal and b) protects against unexpected current or voltage spikes?
This may be too broad a question but asking since this will be the first time I'll be trying to print and etch the PCB. Does this layout look fine? Is it even possible to provide feedback on the PCB layout design? I have done my calculations to ensure the track widths are able to handle the current.