Serial comms with espruino - stty?

Warren Block wblock at
Wed Sep 30 19:16:18 UTC 2015

On Tue, 29 Sep 2015, Stephen Roome wrote:

> Hi folks,
> I've recently been given a tiny ARM chip on a usb board - an Espruino Pico.
> Unfortunately, I'm not having a lot of luck in FreeBSD with this.
> In Linux and OSX the device attaches as /dev/tty.something and
> /dev/cusomething and ...
> screen /dev/tty.something works great on both.
> In FreeBSD however it attaches via umodem as...
> /dev/cuaU0
> /dev/ttyU0
> /dev/cuaU0.lock
> /dev/cuaU0.init
> /dev/ttyU0.init
> and
> /dev/ttyU0.lock
> screen /dev/ttuU0 sort of works however umodem or ucom or tty or something
> seems to buffer the last character of input or output. i.e. typing is hard
> work. screen is effectively always exactly one keypress behind.
> I've played with the stty settings (which I think, but I'm not certain,
> that I have to make to /dev/ttyU0.init for them to actually be applied -
> hey, is this documented somewhere ???) but to no avail.

There is the "Serial Port Configuration" section of the serial chapter 
of the Handbook:

Of course it all depends on how a particular cable is wired.

I got thoroughly sick of RS232 many years back, swore never to wire yet 
another serial cable, and began avoiding it.  But every time I think 
it's dead forever, it comes back.  Most lately, I'm trying to figure out 
why pasting text to a NodeMCU board acts like hardware handshaking does 
not work and loses pasted characters while a line is processed.  Thirty 
years ago, having to set an EOL delay was not unexpected.  Today, well, 
at least it can be trusted to be the same old fight to get it to work.

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