[Flashforth-devel] USB-UART bridge puzzle

[Tristan W. <ho...@tj...>]

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