BS2 with MAX232 serial

astropaul

Hi,
Can you point me in the direction of any HOWTO's or tutorials on using the
MAX232 serial line chip with the BS2 ? My BS2 app needs to do a lot of processing
and so I thought it would be a good idea to off-load the serial line task to a dedicated chip.

Thanks
Paul

PJAllen

Astropaul said...
off-load the serial line task to a dedicated chip

The MAX-232 is a level shifter, it converts logic to +/- 12 (RS-232) and vice versa --·it is not a UART (USART.)

allanlane5

http://www.rhombus-tek.com/co-processors.html has a very nice 8-pin co-processor chip which acts as an RS-232 reciever. That will give you a small RS-232 recieving buffer.

And as has been said, the MAX232 merely shifts the levels from TTL (0 to 5 volts) to RS232 (-10 to +10 volts). So it can't act as a buffer.

astropaul

OK, thanks.

But it looks like that RS232 buffer co-processor is not available.
Are there any other chips I could be looking at?
or any other guides on doing reliable serial comm with a BS2px
Paul

allanlane5

Ah. The one you want is the "Simple Multi-Tasking" coprocessor -- it also acts as an RS232 recieve unit.

astropaul

Doh.
Ok, thanks man!
I checked it out and it looks like just what I need with the receive buffer.
I have ordered one now. To get a headstart on the code, do you have any sample code
that shows how to retrieve data from the receive buffer?
How do you know there is something in the recieve buffer?
Can you check a pin status?

Thanks
Paul

astropaul

It looks like you can also use a MAX3110E as a external UART to buffer stamp serial input.
It has a buffer depth of 8 characters

See
MAX3110E
http://www.wd5gnr.com/suart.htm

Do you know how deep the buffer on the rhombus co-processors is ?

http://www.rhombus-tek.com/co-processors.html

Thanks
Paul