How do i use 70 GPIO pins in STM32F767 Nulceo-144 board for output?

[SShow.1]

I tried to run it but LD7 which is below USB fault lights up

And i think there is too much current taken from the USB which lights LD7 red

I reduced it to 15 GPIO output pins and its fine now

Works good

But my project requires the use of around 70 pins

[TDK]

You can use as many pins as you want, but there is a limit to the maximum amount of current the chip can source/sink. Something in the realm of 200mA. The USB on that board also has a limitation to the amount of power it has available. If you supply an external 5V to power the board, you can use more power. Details are in the nucleo user manual.