onewire with uart

[nui_de]

Hi,

i like to write a onewire library using uart for communication with my onewire bus
as described here:
https://www.maximintegrated.com/en/app- ... mvp/id/214

Is it possible to set the the GPIO01(Tx) to open drain when initializing as uart or
do I need the external open-drain buffer chip?

[Roberthh]

The ouput driver for a Pin supports open drain mode, which is independent form the seleted alternate function. by accessing the GPIO control registers directly, this could be changed after initilization of the UART. Open drain mode can be selected in the Pin class.
I tried:

Code: Select all

from machine import uart, Pin
uart = UART(0,9600)
pin= Pin("GP1", mode = Pin.ALT_OPEN_DRAIN, alt=3)

That has put the TX pin to open drain mode, still sending & receiving
Best Regards

[nui_de]

Thanks Robert,

I will try that out and hopefully have a new and fast onewire library soon