I’ve finally reviewed all the material and converted the old code to
make it
more user friendly as well as to make use of the great blocks GNURADIO
offers. I am talking about the Mueller and Muller clock recovery and
sampler. Now both 1200 and 9600 python code works, both for transmit and
receive. I have isolated the framer functionality in a block, gr_framer,
that takes care of HDLC and G3RUH LFSR scrambling/descrambling. This
block
uses the message queue model to return the packets back to the python
code.
Full option parser support has been added to the python code, so that
usrp
parameters and message to transmit can be passed to the programs via
command
line. A description od the python programs follows. For those
interested,
they can be downloaded at Untitled Document.
Feedbacks and evolutions are welcome.
Matteo, iz2eeq
1200rx.py
usage: 1200rx.py [options]
options:
-h, --help show this help message and exit
-R RX_SUBDEV_SPEC, --rx-subdev-spec=RX_SUBDEV_SPEC
select USRP Rx side A or B (default=A)
-f FREQ, --freq=FREQ set frequency to FREQ
-g GAIN, --gain=GAIN set gain in dB (default is midpoint)
-d, --do-logging enable logging on datafiles
-s, --use-datafile use usrp.dat (256kbps) as input
This program receives packets and show them on terminal in this form:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
CRC C75F C75F
===== Sat Nov 4 11:21:50 2006
fm IZ2EEQ-7 to SXQT16-0 via RELAY-0,WIDE7-7 UIv pid=F0
'+4il .K>
XXXXXXXXXXX
CRC 34EC 34EC
===== Sat Nov 4 11:27:42 2006
fm IK1ZNW-6 to I2ODL-6 via IK2NHL-4 I45^ pid=F0
PC19^0^IK5PWJ-6^0^5452^1^IZ5FSA-6^0^5452^0^IK2XDE-6^0^5432^0^IK5ZUK-6^0^5452^1^I5UXJ-2^0^5451^1^IR1BI-6^0^5451^1^IR8AW-6^0^5452^H2^
he Xs are returned by the framer and indicate a candidate packet whose
CRC
check failed. When CRC check for a packet is ok, the framer prints the
CRC
value to standard output and returns the packet to python, whose
function
printpacket prints it in a readable format.
1200tx.py
usage: 1200tx.py [options]
options:
-h, --help show this help message and exit
-f FREQ, --freq=FREQ set frequency to FREQ
-m MESSAGE, --message=MESSAGE
message to send
-c CALL, --mycall=CALL
source callsign
-t CALL, --tocall=CALL
recipient callsign
-v CALL, --via=CALL digipeater callsign
-d, --do-logging enable logging on datafiles
-s, --use-datafile use usrp.dat (256kbps) as output
This program transmit a message from a source callsign to a dest
callsign
via a digipeater. It is made to work with a basic TX board (the only tx
board I have), therefore it uses the repetition of spectrum of a sampled
signal to go to VHF. I guess the code can be easily adapted for more
serious
transmit boards.
9600rx.py
usage: 1200rx.py [options]
options:
-h, --help show this help message and exit
-R RX_SUBDEV_SPEC, --rx-subdev-spec=RX_SUBDEV_SPEC
select USRP Rx side A or B (default=A)
-f FREQ, --freq=FREQ set frequency to FREQ
-g GAIN, --gain=GAIN set gain in dB (default is midpoint)
-d, --do-logging enable logging on datafiles
-s, --use-datafile use usrp.dat (256kbps) as input
This program receives packets and show them on terminal in this form:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
CRC C75F C75F
===== Sat Nov 4 11:21:50 2006
fm IZ2EEQ-7 to SXQT16-0 via RELAY-0,WIDE7-7 UIv pid=F0
'+4il .K>
XXXXXXXXXXX
CRC 34EC 34EC
===== Sat Nov 4 11:27:42 2006
fm IK1ZNW-6 to I2ODL-6 via IK2NHL-4 I45^ pid=F0
PC19^0^IK5PWJ-6^0^5452^1^IZ5FSA-6^0^5452^0^IK2XDE-6^0^5432^0^IK5ZUK-6^0^5452^1^I5UXJ-2^0^5451^1^IR1BI-6^0^5451^1^IR8AW-6^0^5452^H2^
he Xs are returned by the framer and indicate a candidate packet whose
CRC
check failed. When CRC check for a packet is ok, the framer prints the
CRC
value to standard output and returns the packet to python, whose
function
printpacket prints it in a readable format.
9600tx.py
usage: 9600tx.py [options]
options:
-h, --help show this help message and exit
-f FREQ, --freq=FREQ set frequency to FREQ
-m MESSAGE, --message=MESSAGE
message to send
-c CALL, --mycall=CALL
source callsign
-t CALL, --tocall=CALL
recipient callsign
-v CALL, --via=CALL digipeater callsign
-d, --do-logging enable logging on datafiles
-s, --use-datafile use usrp.dat (256kbps) as output
This program transmit a message from a source callsign to a dest
callsign
via a digipeater. It is made to work with a basic TX board (the only tx
board I have), therefore it uses the repetition of spectrum of a sampled
signal to go to VHF. I guess the code can be easily adapted for more
serious
transmit boards.