I just noticed that I have no FM radio reception on some frequencies when my Arduino is on. I tried all sorts of things and discovered that my I2C OLED emits extremely high frequencies. The I2C cable is only 10 cm long. Only when I had lowered the clock rate from 400k to 100k, 90% of the interference was gone. Has anyone had such experiences with EMI?
Since your OLED uses I2C, it has it's own micro controller which is the source of the EMI. The solution, if this is a real problem is to put the OLED assembly in a shielding metal enclosure and ground to the common ground.
Paul
Well not technically, no, its mainly emitting low to very high frequencies, since
extremely high frequencies are defined as 30GHz to 300GHz:
https://en.wikipedia.org/wiki/Extremely_high_frequency
whereas you'd seeing issues at VHF (very high frequencies, 30MHz--300MHz).
https://en.wikipedia.org/wiki/Radio_spectrum#ITU
You're discovering why logic speed signals need careful attention to shielding and layout,
why ferrite toroids are often seen on cables, and many microcontrollers have a pin
"drive-strength" setting available in the hardware to control the speed of logic transitions.
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