FYI, switchmode supplies don't need microprocessors. Many are entirely analog, most of the rest use a small amount of digital logic to control the switching. EG

FYI, switchmode supplies don't need microprocessors. Many are entirely analog, most of the rest use a small amount of digital logic to control the switching. EG check out the LT3574 datasheet[1] pg 6: the only digital logic is the master latch, and it's just doing the "thermostat-style" switching I mentioned above. Or for an even more basic system: the ringing choke converter[2]. Lots of cheap power supplies use these because they are very simple and require no digital circuitry. Edit: also to get a given voltage out of a microprocessor, you just use an analog-to-digital converter (ADC). Some have them built in, others are external. I like the AD9850 for hobby work, as it has a high resolution and is quite fast. If you need a large voltage range there are ADCs available for that, or you can amplify the signal from a lower voltage one. WRT your issues with sensitivity to SMPS, it probably is audible noise. See if Screen Tunes[3] causes symptoms, it causes audible (but quiet) coil whine of varying frequency on most monitors I've tried. Your issues are unlikely to be directly caused by RF EM, but the side effects of the systems that generate such signals are often detectable by people. [1] http://cds.linear.com/docs/en/datasheet/3574f.pdf http://cds.linear.com/docs/en/datasheet/3574f.pdf [2] http://mmcircuit.com/understand-rcc-smps/ http://mmcircuit.com/understand-rcc-smps/ [3] https://thume.ca/screentunes/ https://thume.ca/screentunes/