Paul:

 I ordered a USB Data Acquisition board from Digikey to use when testing
 my HomebrewedGlassPanel. I didn't order the programmable
 development/testing board you mentioned, I didn't want to take the time
 to learn the language.  So I just ordered a dumb interface board with 20
 I/O ports, 14 that can be used A/D.

 If I choose to put a custom glass-panel in my project, I think I would
 want the control functionality separated as much as possible from the
 display-system anyway, so I will not worry about ECU functionality for
 now. ...



 R. Berglund

 Send pictures of the board you ordered and the price.
 Did you look at this one?
 http://www.hytekautomation.ca/U120816.aspx?productId=1

 Paul Lamar


No ... I had not looked at that one.  I spent about 15 minutes surfing
the web, came up with a handful of manufacturers/vendors, but most units
were in the several-hundred-dollar range.  The one I ordered was
$49.95 ... a bit out of my price range, but seems to be fairly easy to
connect to; it requires no additional sockets, I will not need to spend
a weeks worth of days and nights learning how to program the thing.
That should be worth $20 to me

This is the unit:
http://search.digikey.com/us/en/products/DLP-IO20/813-1027-ND/2135093

R.Berglund

Wow that is a bargain. I wonder what CPU chip they are using?
The Linux driver is a huge advantage. The USB port works on Linux.
It has my favorite connectors on it as well.

Hytek comes only with a Windows driver.

IMHO the missing link at the moment is how do you access it on Linux.
It appears you need to write a C program to pipe the data to your TCL
program.

 Perhaps a Linux serial terminal program will read
the USB port with high speed serial ASCII data coming in.

Does TCL have a command to read a USB port?

HyTek supplies a windows program that stores the data in a file on the
hard disk in comma delimited form readable by a spread sheet.

Paul Lamar

TCL Read Command USE WITH SERIAL PORTS
For most applications a channel connected to a serial port should be
configured to be nonblocking: fconfigure channelId -blocking 0. Then read
behaves much like described above. Care must be taken when using read on
blocking serial ports:

read channelId numChars
    In this form read blocks until numChars have been received from the serial port.

read channelId
    In this form read blocks until the reception of the end-of-file
character, see fconfigure -eofchar. If there no end-of-file character has
been configured for the channel, then read will block forever.

EXAMPLE
This example code reads a file all at once, and splits it into a list, with
each line in the file corresponding to an element in the list:


set fl [open /proc/meminfo]
set data [read $fl]
close $fl
set lines [split $data \n]

---------------------------------------------

It appears that READ can handle only ASCII data with the DLP
sends out binary. I could be wrong.

--------------------------------------------------------------

You can either utilize the TestApp program (described in the following
section number 8) provided
with the DLP-IO20, or write your own program in your language of choice.
Begin by opening the COM
port, and send multi-byte commands as shown in Table 2 below. There is no
need to set the baud
rate because the DLP-IO20 uses a parallel interface between the USB IC and
the microcontroller. The
Ping command can be used to locate the correct COM port used for
communicating with the DLP-
IO20, or you can look in Device Manager to see which port was assigned by
Windows.

----------------------------------------------------------------
Looks like you will have to write some that looks like this in C for Linux.
I would be nice if the DLP talked ASCII.

However you are getting closer. Almost there.

Paul Lamar