hpcap version 0.1, Copyright (C) 2008 Jeff Otterson [email protected] 28 November 2008
This software allows you to attach various devices that emit screen dumps in PCL5 to your linux box, and capture the screen dump in a format that may actually be useful. I wrote this to use with my HP 8921 cell site test set, but it also works with my Tek TDS 210 Oscilloscope.
The test equipment should be set up to send it's screen prints to a HP laserjet configuered on the serial port. The program searches for the PCL5 data in the serial stream, and captures an image.
The program creates a PBM file as output, then calls the 'convert' utility (from ImageMagick) to create a gif. Call me lazy. I did not want to write my own gif output function, or bother to link some library to do that. Should you decide to put that in, then I'd love to have a copy. (PBM is the least efficient storage method possible, using about 2 bytes per pixel, but disk space is cheap and my time is precious -- so there!)
This program is derived from my tdsdump program of 1998, but where tdsdump just forwarded the 'scope's output to the printer, this program actually captures the bitmap. Yee-haw.
I am going to keep the latest version on GitHub
hpcap comes with ABSOLUTELY NO WARRANTY; See COPYING for details. This is free software, and you are welcome to redistribute it under certain conditions; See COPYING for details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
Optional parameters are :
-t input tty default /dev/ttyS0
-l lpr command default lpr -r %s, does nothing!
-v print version and exit
-h this help screen
Use the serial port on the HP8921 to output data. Wire it to your Linux box's serial input per the HP documentation. You can use a regular RJ-11 connector here, you don't need the outer two pins that are on the RJ-12.
There is NO FLOW CONTROL!
For the TDS210, set it up like this:
Utility->Options->Hard Copy Setup
Layout: either LANDSCAPE or PORTRAIT.
Format: LaserJet
Port: RS232
Utility->Options->RS232 Setup
Baud: 19200
Flow Control: Hard Flagging
EOL String: CR
Parity: None
Serial Cable Wiring:
9 Pin Female 9 Pin Female
2 Receive Data <-------------> 3 Transmit Data
3 Transmit Data <------------> 2 Receive Data
5 Signal Ground <------------> 5 Signal Ground
7 Request to Send <----------> 8 Clear to Send
8 Clear to Send <------------> 7 Request to Send
1 Carrier Detect <------+ +-> 1 Carrier Detect
4 Data Terminal Ready <-+ +-> 6 Data Set Ready
6 Data Set Ready <------+ +-> 4 Data Terminal Ready
9 Ring Indicator (N/C) (N/C) 9 Ring Indicator
For some reason, the TDS210 takes a minute or two to dump the hardcopy. I don't know why, but don't start looking for something wrong for two or three minutes after pressing the hardcopy button.