5v power source will have an effect on video output interference.
If you see a rolling ripple effect on your video output check the quality and setup of your power source.
This effect is shown as below:
This is an effect can be caused a few ways - one is via a common ground loop issue, another is the other due to 'AC ripple' which will create signal noise regardless of the quality or length of your cables, and can also be caused by using very poor quality (often very cheap) switching power supplies found on online market places.
Resolution:
Either find:
cleaner power source (ie a 5v portable mobile phone battery power supply is a quick fix using a chopped usb cable)
a 5v dc to dc isolator (a small chip that separates the common ground)
add a simple low pass filter to the 5v input
add a smoothing capacitor to control for the ac ripple
a Low Drop Output (LDO) voltage regulator to condition and clean the 5v signal (this will likely need additional capacitors and resistor).
Or use any combination of the above. There are plenty of low pass filter designs on the web.
In most cases, I found just using a quality 5v mobile phone wall charger and cutting up a usb cable removed almost all of the noise.
Despite trying all sorts of power cleaning circuits on a very poor quality 5v power supply, it is much better to start with a quality 5v supply first.
5v power source will have an effect on video output interference.
If you see a rolling ripple effect on your video output check the quality and setup of your power source.
This effect is shown as below:
This is an effect can be caused a few ways - one is via a common ground loop issue, another is the other due to 'AC ripple' which will create signal noise regardless of the quality or length of your cables, and can also be caused by using very poor quality (often very cheap) switching power supplies found on online market places.
Resolution:
Either find:
Or use any combination of the above. There are plenty of low pass filter designs on the web.
In most cases, I found just using a quality 5v mobile phone wall charger and cutting up a usb cable removed almost all of the noise.
Despite trying all sorts of power cleaning circuits on a very poor quality 5v power supply, it is much better to start with a quality 5v supply first.
Will consider adding to a future pcb revision.