I have developed working stationary electronics for a piezo injector flow bench system. It uses AVR uCs, to PWM control the output signals shape. The system works well, supplied with a switch mode power supply and short load cable lengths. My next step is to make the system mobile for installation in a vehicle. For this application, the 12V power and load cables may extend a few to several feet. Due to the high voltage, and high peak currents, my spider senses are tingling :).
I have concerns in doing this correctly, I welcome guidance from this group. The attached block diagram outlines the general circuit.
My main concern is the logic ground tie between the AVR circuit and the output power circuit, and also case ground.