FreeBSD and controlling an alarm via relay
bsam at ipt.ru
Tue Jul 5 19:56:33 UTC 2011
On Tue, 5 Jul 2011 17:30:03 +0300 Achilleas Mantzios wrote:
> Most probably i'll go for something cheaper like this one
> Could i use the ucom driver to talk to the USB device like a normal
> serial device, via /dev/cua*** ?
I use USB-to-7-RS232-ports devices via /dev/cuaU00-/dev/cuaU06.
Works like a charm. But you should find out what chip is used
for USB-to-RS232 bridge and (kld)load a driver.
> The above link says one needs to talk to the relay with:
> 8 Data, 1 Stop, No Parity,Baud rate : 9600
I've never changed those parameters.
> and the commands look like:
> FF 01 00 (HEX)
> 255 1 0 (DEC)
> could i be able to specify those over ucom?
> do you know any application, perl library, utility or just a guide for
> standard C serial port programming?
> i have used mgetty/vgetty in the past to control some modems.
> I do not know if there any fancier methods to access the serial port,
> but this is how i used to do it, back in 7.*
> /usr/local/bin/vm shell -l cuad1 -S onhook_offhook.pl
> where onhook_offhook.pl reads like:
> use Modem::Vgetty;
> my $v = new Modem::Vgetty;
> if i could speak directly with e.g. "255 1 0" like
> $v->send("255 1 0");
> that would be awesome...
> i guess i will have to try it out.
I use python for scripting and it is as simple as write(data) and
HTH and WBR, bsam
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