[ECOS] Simple serial comms

Nick Garnett nickg@ecoscentric.com
Thu Jul 2 14:24:00 GMT 2009


grahamlab <graham.labdon@cranems.co.uk> writes:

> Hello everyone
> I am developing an ecos application using the STM3210E dev kit.
> I want to do some serial comms but cannot receive more than 128 bytes.
> I have tested this program using minicom to send the bytes
> 
> Does anyone know how I can configure it to receive more bytes?
> 
> http://www.nabble.com/file/p24306125/rawRead.cpp rawRead.cpp 

I just happened to be doing some serial testing on an STM32 board
here, so I gave your test a go. I don't see any problems. As you can
see from the output below, I can just lean on a key and it comes
through in ~30 character chunks. So buffer sizes don't seem to be a
problem.

How are you sending the bytes?
The USART does not have a FIFO, so in the absence of flow control,
characters might be missed.

I was running this out of on-chip RAM rather than external RAM. That
might make a difference. Although, at 9600 baud this is unlikely.

What sort of RS232 device are you using on the host side? I have seen
some odd behaviour from USB to RS232 adaptors. But that was mostly
around flow control behaviour. I was using an FTDI based adaptor for
the test below.



opened port
EAGIN res -11 msglen 0

EAGIN res -11 msglen 0

EAGIN res 0 msglen 2
ff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 29
fffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 30
ffffffffffffffffffffffffffffff
EAGIN res 0 msglen 23
fffffffffffffffffffffff



-- 
Nick Garnett                                       eCos Kernel Architect
eCosCentric Limited    http://www.eCosCentric.com       The eCos experts
Barnwell House, Barnwell Drive, Cambridge, UK.      Tel: +44 1223 245571
Registered in England and Wales:                         Reg No: 4422071


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