Re: [Flashforth-devel] USB-UART bridge puzzle

[Colin T. <co...@tp...>]

Hi Tristan,

using a ch340 based usb<>serial, no buffer and doesn't need flow control

FTDI232 and cu with flow control

colin@treehome:~$ cu -f -l /dev/ttyUSB0 -s 1000000
Connected.
(cr)  ok
~.
Disconnected.

with no flow control

colin@treehome:~$ cu -l /dev/ttyUSB0 -s 1000000
Connected.
(cr) ~.
(cr) ~.
(cr) ~.
(cr) ~.
(cr) ~.
(cr) ~
Disconnected.

so between the buffer and flow control ...

Colin

On 20/11/21 5:59 pm, Tristan Williams wrote:
> Hello Mikael,
>
> Thank you. I tried adding pause to the bridge word but to no
> avail. Still no data received if the serial data is sent
> infrequently. No data received after a good long wait. I have just
> moved my winter project to the PIC18F25K50 (to get more flash storage)
> from the PIC18F14K50. I didn't recall anything similar happening with
> that chip, so I tried the bridge back on my PIC18F14K50 setup and - it
> worked (without pause). It would seem to me that the two chips are
> responding differently to what I think is the same code. A puzzle.
>
> Best wishes,
> Tristan
>
>
> On 20Nov21 06:23, Mikael Nordman wrote:
>> Hi,
>>
>> TXU collects up to 8 characters before it sends the buffer to the
>> USB line.
>>
>> There is a timeout 2+TICK_TIME milliseconds to send the buffer if no
>> data arrives to TXU. TICK_TIME is defined in the config file.
>>
>> That timeout is handled by PAUSE.
>>
>> So you should have seen data on the USB line after 8 seconds.
>> If not then there is some other problem.
>>
>> Try this
>>
>> : bridge
>>      u1-
>>      begin
>>          pause rx1? if rx1 txu then
>>      again
>> ;
>>
>> BR Mikael
>>
>>
>> On 2021-11-19 21:09, Tristan Williams wrote:
>>> Hello,
>>>
>>> I have a small mcu, sending serial data over its hardware uart
>>> (38400-8N1) to the RX1 port of a PIC18F25K50 running FlashForth over
>>> USB. I am trying to see/capture that serial data using FlashForth as a
>>> USB-UART bridge
>>>
>>> : bridge
>>>      u1-
>>>      begin
>>>          rx1? if rx1 txu then
>>>      again
>>> ;
>>>
>>> as per https://sourceforge.net/p/flashforth/wiki/USB-UART%20bridge/
>>>
>>> If the serial data is sent as a continuous stream then it arrives as I
>>> expect. If the data is subject to a delay in transmission - i.e. I put
>>> a 1 second delay between each data byte, the data does not arrive. It
>>> seems, perhaps, that the bridge has stalled in some way whilst waiting?
>>>
>>> I hooked up a second usb-serial adaptor (FTDI) to the small mcu TX and
>>> the delayed data is definitely there, arriving with a one second delay
>>> between each data byte. If the data is streamed continuously, both the
>>> bridge and the FTDI see it; if I introduce a delay, only the FTDI sees
>>> it.
>>>
>>> Any light on what I might be doing wrong would be very gratefully
>>> received.
>>>
>>> Best wishes,
>>>
>>> Tristan
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Flashforth-devel mailing list
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>>> https://lists.sourceforge.net/lists/listinfo/flashforth-devel
>> -- 
>> --
>> Mikael
>>
>>
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