Parallel Output of a Byte

[John Hasler]

I need to write a byte to a GPIO port in a single operation. I can use any set of pins and any port. I've searched the documentation and can see no way to do it other than eight seperate pin() operations or using assembler or C.

[Roberthh]

You can use viper code to write directly to a port register, and you can use uctypes.bytearray_at(addr, size) to read & write to a phsical memory location. For viper code, you find a documentation here: http://docs.micropython.org/en/latest/r ... de-emitter
I used that a lot in a SSD1963 driver for direct 8 bit wide port access. The sample driver is here:https://github.com/robert-hh/SSD1963-TF ... /TFT_io.py

[John Hasler]

Viper was the hint I needed. Thank you. Don't know why that was so hard to find.

[jimmo]

I need to write a byte to a GPIO port in a single operation.

You can do this without Viper

On the STM32 port there's a 'stm' module which gives you constants for most registers. Combined with machine.mem32 you can pretty much do anything.

Code: Select all

import machine
import stm

machine.mem32[stm.GPIOA] = ...

[Roberthh]

machine.memxx calls are slow. If you need fast actions, viper works better.