Investigation group

Ned Konz ned at
Mon Apr 7 15:14:23 UTC 2003

On Monday 07 April 2003 08:03 am, Sabina A. Schneider wrote:
>     We are an investigation group of the University UTN Reginal
> Buenos Aires. We are selecting the new platform for our proyect,
> that's why we are interested in your product. We were investigating
> the characteristics in Internet, but there are very important
> points out of the range: - Is there the posibility to connect to
> the port RC232 and USB through a library of methods, alreay
> implemented?

You don't say what operating system you're using (this is important, 
as the Mac serial support has lagged behind the platform). However, 
there is the following:

* SerialPort class that allows non-blocking reads (i.e. polling) of 
serial ports. You set up all the parameters before opening the port. 
I don't think you have direct control over the handshake/status 
lines, though. This works under Linux and Windows (and maybe 
Windows/CE?). On older Macs (ones with built-in serial ports) you can 
use this. On newer Macs, if a serial port doesn't support older MIDI 
stuff you can't use it with SerialPort.

* You can use the AsyncFilePlugin for async reads and writes that 
block just the Squeak Process (thread) that is doing the reading or 
writing. I have written a few new methods for AsyncFile that let you 
do this kind of thing easily. However, you don't have control over 
the serial port parameters.

* the OSProcess plugin also lets you do async file read/writes. 
However, you still can't do the requisite ioctl directly. But you can 
run (for instance) a stty call as an external process using 
OSProcess. Or you may be able to open the port using SerialPort, 
close it, and then open it using the async file methods to set the 

* there is no *direct* USB support in Squeak. However, depending on 
how your USB device presents itself, it may still be usable. For 
instance, USB to serial converters can be used with the above 
SerialPort support. I've just designed a little microcontroller board 
with a USB interface that looks like a serial port (see; this works with Squeak using the 
SerialPort support.

> Is there the possibility to connect with the
> standard X10 through methods already implemented?

Depends on how much of the protocol you want to do yourselves. 
Clearly, if you have a serial X10 device and know what bytes to 
send/receive from it you can do it.

If you're using Windows and if there is a DLL that controls your X10 
device, you may be able to use the FFI (foreign function interface) 
support in Squeak to talk with this DLL.

I assume you've already googled for X10 Squeak; this would show you 
Kevin Fisher's X10 Driver package at . He uses FFI.

Ned Konz

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