3V SPI/I2C voltage translation

leung先森

Basiclly, 3.3v is the same as 3v .
But if your MCU is serious about voltage controled, just try apply 3v to your MCU.
I trust your MCU have its Float voltage.

leung先森

big_whit Posted at 2/5/2018 03:13
Does anyone actually knows if the RK3399 VDDIOs bank @3.0V are Voltage tolerant to VDD+0.3V . Trying ...

u can try to set up the group gpio of the UART2DBG_RX  from the hardware datasheet.
It is controled by pmu.