Fredrik,
What you want to do is exactly what the Springboard interface is all about.
Their interrupt handler is very well documented and should have no problem
handling input at this speed. The downside is that you will need to make some
sort of interface board between your 160 bps line and the Springboard bus.
What I suggest you do is develop a device that reads at least 2x the rate that
you need, develop the interrupt handler as a software UART, parse the bit
stream and you should be in business.
Steve
Fredrik Ohrn wrote:
> Hello!
>
> I have embarked on a project to hook up my Palm to the diagnostic link
> connector on my old Chevrolet. The onboard computer outputs a non standard
> serial data stream at 160 bps. To receive the data I have decided to
> connect it to the HotSync button input on the Palm.
>
> I'm now trying to write an interrupt handler that receives and decodes the
> data. Idusted of my old Amiga assembly skills and started hacking away but
> I'm stuck, nothing seems to work and documentation is sparse.
>
> Is there any 'low level' documentation available? How the OS interacts
> with the hardware and similar things? Reading the Dragonball documentation
> and reprogramming some registers seems easy at first, but geting it to
> work is another story.
>
> Is there any PalmOS supported way of installing an interrupt handler?
> If not, is it possible to disable the original INT1 handler and insert my
> own without disrupting the system too much?
>
> I also need to do timing with 1 millisecond resolution, the 10 msek tick
> count is not accurate enough. Can I just grab timer hardware and reprogram
> it as long as I restore everything when the application exits or will it
> have odd side effects in the PalmOS?
>
> Any help appreciated!
>
> Regards,
> Fredrik Ohrn
