Re: [avr-gcc-list] ADB-Project: USART and half duplex?

[Russell Shaw]

address@hidden wrote:
> Hi,
>
> We're two students working on a project to enable communication between an
> ADB-keyboard (the old ones from apple; ADB = Apple Desktop Bus) and a Crossbow
> MicaZ. We're right now just at the beginning, searching for informations. At
> the moment we're wondering if the USART maybe also suited for half-duplex
> communication (which is needed for ADB). If someone could provide us with some
> information here, we would be very glad.
>
> sincerely
>
> Patrick Maechler
> CS-student @ Uni Basel (CH)

You connect the TX line of the uart output to the RX line of the uart input.
You'll need a separate port bit on the avr to make the uart output a high
impedance and disabled when not transmitting. You'll need to find some
non-standard uart tho. You should ask this question on avr-chat or some
other hardware list.