I have a PCB I designed for a project and I'm testing it. In general, it has some analog channels and a MCU to handle all the logic and the communications. I used an isolated DC-DC converter since this will be connected to a rather noisy power supply.
Anyway, I have left it connected working and communicating to the PC for long periods of time to test its stability and sometimes it can work for days and sometimes it stops working. It's being difficult for me to see what's going on because is more the time that it works correctly than the times it just stops working. I think that external EM noise could be the problem (nearby radios, motors, other switching supplies, etc) but I'm not sure.
My specific question is: What can I use to generate high amounts of noise and test my device to see if it can survive?
I thought of just putting a radio antenna near to it and hit the transmit button but I'm not sure if this would be as bad as possible. I need a way of generating some serious noise, the more the better.
UPDATE: Also I'm using galvanically isolated RS2232 IC from maxim and galvanically isolated SPI IC to comunicate with the ADCs (since I'm not using the MCU ADC) and I have 4 layer PCB with 4 different isolated power and ground planes (one for each stage) without slots or current return interruptions. The only common ground points I have is at the voltage regulators because nevertheless I have separated LDOs for every stage (4 in total), they all have to have a common ground point at the main supply. I'm still not completely sure if I'm completely noise-free. As per the comments before I think the may be a coding issue but I still want to noise-test the system to be completely sure is not a hardware issue.