gr-satnogs/examples
Manolis Surligas 8424f5930d Remove obsolete examples 2018-03-20 20:40:13 +02:00
..
.gitignore Add matched filter implementation for CW noise reduction 2016-01-17 23:59:05 +02:00
README.md Fix markdown 2016-04-24 14:57:09 +03:00
afsk1200_example.grc Remove obsolete examples 2018-03-20 20:40:13 +02:00
ax25_example.grc Fix AX.25 encoder/decoder 2018-03-20 20:40:13 +02:00
debug_fsk_transceiver_osmocom.grc Remove obsolete examples 2018-03-20 20:40:13 +02:00
debug_fsk_transceiver_uhd.grc Remove obsolete examples 2018-03-20 20:40:13 +02:00
test_morse_decoder.grc Add minimum frame length on the morse decoder 2018-02-01 21:59:45 +02:00
test_rigctl.grc Add a flowgraph example for the receiving rigctl commands 2016-04-11 20:24:17 +03:00

README.md

Examples

This directory contains a set of useful examples and flowgraphs for testing and demonstrating the performance of the different components of this OOT module

Files

  • morse_ref.wav : This is a reference file containing the HELLO WORLD message. The file is sampled at 8 KHz and the audio frequency is 700 Hz. The Morse code Words per Minute (WPM) is about 20.

Flowgraphs

  • test_matched_filter.grc: Demonstrates the performance of the implemented matched filter for CW decoding.

  • morse_decoding_flowgraph.grc: This flowgraph decodes a CW signal and prints the corresponding message at the stdout. To demonstrate the capabilities of the decoder, signal and noise power GUI sliders are provided for easy testing and experimenting.

  • ax25_example.grc: This flowgraph semonstrates the AX.25 encoder and decoder. It has two different AX.25 payload source blocks. The first one is the Debug Message Source block that assigns as payload a predefined message, whereas the second one is a UDP Message Source block that receives the AX.25 payload from a UDP packet.

  • test_rigctl.grc: This particular flowgraph demonstrates the capabilities of the module implementing a portion of the rigctld functionality. It received rigctl commands through a TCP socket and produces the appropriate messages. In the example these messages are received from the Doppler correction block. To generate rigctl commands you can use the GPredict software. Note that you have to specify the frequency of the transmitter satellite. As this block does not use any satellite signal rather than a simple sine, you do not expect any correction at all. However you will be able to see how smoothly the sine peak is drifting. This drift in normal situations will be the correction offset.

  • debug_fsk_transceiver_uhd.grc: This flowgraph provides an FSK transceiver. It was designed having as reference the CC1120 chip, but using properly the parameters of the FSK encoder/decoder, it can be used as a generic FSK modem. However the FSK framing format should follow the format:

Preamble SYNC Word Payload length Payload CRC
x repeating bytes y bytes 1 B, 0-255 variable 2 B, optional

The flowgraph transmits messages that are produced from the Debug Message Source block. Furthermore, frame payloads can be derived from a UDP message source block. Just use a tool like netcat to deliver arbitrary payloads through UDP messages.

  • debug_fsk_transceiver_uhd.grc: This flowgraph provides exactly the same functionality as debug_fsk_transceiver_uhd.grc does. However, it uses the Osmocom SDR source and sink blocks for non UHD based SDR hardware (e.g BladeRF, HackRF, etc).