Serial script in cygwin

bob800 · 12-26-2012, 09:37 PM

Hello,

I've built an EEPROM programmer circuit with an Arduino microcontroller as described here: http://z80dave.blogspot.com/2011/09/...er-part-2.html. The specifics are not important, but I need a script which will accomplish the following things:

1) open a file (format is not important) containing the data in hexadecimal to be transferred
2) send 64 bytes of data, wait a few seconds, then send another 64 bytes
3) repeat step 2 until all data has been transferred

The website I linked to provides the following script:

Quote:

eeprom_send.sh

Code:

#!/bin/bash
split -C 64 ${1} ${1}.part.
for part in `ls ${1}.part.*`
do
 cat ${part} >> ${2}
 sleep 1
done
rm -f ${1}.part.*

To use it type:

Code:

./eeprom_send.sh zx81.rom /dev/ttyACM0

Since I run Windows, I tried to execute this script under Cygwin, but I received an error message:

Code:

./eeprom_send.sh: line 4: syntax error near unexpected token `$'do\r''
'/eeprom_send.sh: line 4: `do

Nonetheless, the script does split the initial file into a number of individual 64 byte portions (e.g. zx81.rom.part.'aa,zx81.rom.part.'ab, etc.) No serial data is sent, however. (I did leave the Arduino serial monitor open during the execution, as instructed by the website)

Having no linux experience, I don't really know what to do at this point. Any suggestions would be greatly appreciated!

ntubski · 12-27-2012, 05:53 AM

\r is a carriage return, in Windows newlines are encoded as \r\n, but in unix (and cygwin (by default)) newlines are just \n. I believe cygwin comes with the dos2unix command which will translate a file's newline encoding. Or, if you are using a text editor that isn't notepad, it can probably do the conversion too.

Also

Code:

for part in `ls ${1}.part.*`
## should be just
for part in "${1}.part."*
## Don't parse ls

bob800 · 12-27-2012, 10:35 AM

Thanks! That solved my initial problem, but now it seems that something's wrong with the serial communication...

When I used "/dev/ttyACM0" to address the serial/COM port (as instructed by the site I linked), the script would execute properly, but nothing was happening on my Arduino. So I did a bit of research and changed "/dev/ttyACM0" to "/dev/ttyS2", which corresponds to the COM3 port on my computer.

Now, the Arduino is blinking as it should, but the EEPROM contents remain unchanged! Before I fiddle around with my Arduino sketch I want to be sure that I'm understanding the way linux manages the COM ports...

What does "ACM0" actually mean? How is this different than "S2"?
Assuming that everything works correctly, in what form is the data actually sent through the serial port? I have my Arduino sketch setup to receive literal hex characters... 'F', 'D' '2' (this works when I type strings like "AD E2 2A" into the Arduino COM monitor). For the linux script, I typed the hex values into a hex editor and saved the data as a text file... Will the hex values transfer as characters like I'm hoping?
The site I'm referencing mentions that the Arduino COM monitor must be open in order for the script to function correctly... however, after I changed ACM0 to S2, the script only functions when the COM monitor is closed (I get a permission denied message). How does the script know what baud rate to use?

Thanks in advance!!

ntubski · 12-27-2012, 05:58 PM

Quote:

Originally Posted by bob800

Assuming that everything works correctly, in what form is the data actually sent through the serial port? I have my Arduino sketch setup to receive literal hex characters... 'F', 'D' '2' (this works when I type strings like "AD E2 2A" into the Arduino COM monitor). For the linux script, I typed the hex values into a hex editor and saved the data as a text file... Will the hex values transfer as characters like I'm hoping?

The script uses cat, so it does no interpretation of the file contents; it really depends on the hex editor. You can try running xxd or od -t c on the file to see how it's encoded. But if you want to transmit text, why not just use a text editor?

Unfortunately, I don't know anything about serial ports, so I can't help with your other questions.