[mcm_xyz]

As many people asked me for it here it is...

Mihai

[matt_wiersz]

Hi Mihai,
I have build several DC servo controllers based on Elm Chan design and have a question for you:
Not having analyzed your code very carefully does it matter if rx and tx lines are pulled up or down such as in your design?
Also, will there be a need for change in code if my encoder output lines are pulled up instead of down?
Thanks and congratulations on well designed project, Matt

[mcm_xyz]

Hi Mihai,
I have build several DC servo controllers based on Elm Chan design and have a question for you:
Not having analyzed your code very carefully does it matter if rx and tx lines are pulled up or down such as in your design?
Also, will there be a need for change in code if my encoder output lines are pulled up instead of down?
Thanks and congratulations on well designed project, Matt

hello Matt

I think there is no rule here... when connected to a line matching adapter like the one included in the rs232-usb adapter, does not matter. When left unconnected it's important to have a pullup or pulldown not to pick up noise. you can remove the external resistors if you wish and enable internal pullups in the atmega if you wish.

Mihai