[REBOL] Serial Communication - Desperately Seeking...
From: webmaster::windsweptfarm::com at: 20-Oct-2001 11:08
Dear List,
Does anyone have any experience opening a read only connection to a
serial port through Rebol?
I have thrashed around with this for many hours and have developed some
code that is guaranteed to yield the blue screen of death but not a lot
of serial communication.
Basically I want to open com2 in the following configuration:
Read only
4800,8,n,1
The device on the other end is a Garmin gps which is spitting out NMEA
sentences that are comma delimeted. (see below for typical sentence)
I have succesfully changed the communications parameters but I have been
unable to "effectively" capture the output.
I have opened and closed the port succesfully according to my breakout
monitor chained into the serial cable. I clearly see the DTE led come on
and off when issuing open and close commands. The close command does not
clear the RTS led when executed. I assume that the port has been opened
in Read/Write mode and is waiting for an RTS acknowledgement. Given that
I do not want to write to the serial port at this time I would prefer to
open the port in read only mode.
My re-entry time after crashing the machine is excessive to say the
least.
Loading all the docs, editor, rebol, etc. is a cruel punishment for not
knowing the ins and outs of Rebol. It is most discouraging to say the
least.
If someone could take pity on me and my plight I would be most
appreciative.
Please don't write me an application, (I blush at "excessive" charity)
just a quick snippet to generate a stream of data from the gps hanging
on the serial port. Once I can get some data flowing properly I will
attempt to rise to the next challenge on my own wobbly Rebol legs.
Thanks in advance,
Jim
Typical data stream from GPS:
$GPGGA,092204.999,4250.5589,S,14718.5084,E,1,04,24.4,19.7,M,,,,0000*1F
Some basic types of NMEA sentences:
Description
$GPGGA Global positioning system fixed data
$GPGLL Geographic position - latitude / longitude
$GPGSA GNSS DOP and active satellites
$GPGSV GNSS satellites in view
$GPRMC Recommended minimum specific GNSS data
$GPVTG Course over ground and ground speed