Re: [Sdcc-user] Setting up and sending serial messages

[Peter <pl...@ac...>]

On Sat, 18 Jun 2005, J S wrote:

> Ahh, didn't know I needed to define my own putchar.  I
> decided to try this first since I had the code already
> set for using printf_tiny.  I added in the putchar
> function and then tried to output some stuff to the
> LCD screen.  However, only the first character of a
> string is displayed and nothing else.  Not sure if its
> because this putchar function is a synchronous one
> (the lcd module wants asynchronous).  Any help would
> be great.

putchar is *synchronous* in the application context. It causes 
*asynchronous* serial data to be output on Txd when called. The putchar 
that uses interrupts is *asynchronous* and sends *asynchronous* data to 
Txd.

What does the serial lcd datasheet say about delaying (pacing) between 
sending characters ? Is there a specific format ? Don't you have to set 
auto-increment or something ? Serial LCDs are not standard.

Peter