
Displaying graphics and text on an oscilloscope screen
While playing with an old Hameg HM504 and the Tektronix 465B oscilloscope that I repaired recently, I thought that I should do yet another mandatory tinker project: Using a microcontroller to write text on an oscilloscope screen via the XYZ-mode. And so I designed a small USB powered board around the STM32G441KBT6 which seems to be my go-to microcontroller nowadays. Its fairly capable dual channel 12-bit DAC (up to 5 MSPS) comes in really handy for generating the x- and y-components. Initially I thought about using a discrete 8-bit R2R network to modulate the brightness with the Z input, but after testing the circuit I finally decided keep it simple and just implement blanking with just a single GPIO output. ...