Re: [ECOS] Simple serial comms

[Nick Garnett <nickg@ecoscentric.com>]

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

> 
> I have tried flow control but to no avail
> there must be a way to receive more than 128 bytes has anybody got any other
> suggestions

Flow control should entirely solve your problem. Did you enable the
same kind of flow control at both ends of the connection?

I have run tests that successfully transfer larger quantities of data
at higher baud rates for long periods. So I don't believe there is a
significant problem with the basic driver code.

Some other things to try:

- Test against a host with a real RS232 device. USB adaptors can do
  weird things. It is worth eliminating this as a cause of problems,
  particularly with regard to flow control.

- Try increasing STM32_RXBUFSIZE in the driver source to 128 or
  more. Also add a diag_printf() to the overflow branch in the ISR to
  see if it triggers.

- Avoid diag_printf() calls while waiting for data. If you are running
  via GDB these calls can cause interrupts to be disabled while the
  output is being sent. This may cause the driver to miss characters.

- It may be instructive to work out exactly which bytes are lost in
  each message. This may give a clue as to which FIFO or buffer is
  filling up.


-- 
Nick Garnett                                       eCos Kernel Architect
eCosCentric Limited    http://www.eCosCentric.com       The eCos experts
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