HorusHighSpeed

Modulator and glue code for the 100kbps SSDV experiment.

The transmit side is designed to run on a Raspberry Pi, and the UART (/dev/ttyAMA0) is used to modulate a RFM22B in direct-asynchronous mode. I expect other transmitters could probably be used (i.e. NTX2's or similar) at lower bandwidths.

Dependencies

• Python (2.7, though 3 might work with some small mods)
• SSDV (https://github.com/fsphil/ssdv)
• crcmod (pip install crcmod)
• numpy (for debug output tests)
• PyQt4 (for SSDV GUI)

Main Programs

• rx_ssdv.py - Reads in received packets (256 byte SSDV frames) via stdin, and decodes them to JPEGs. Also informs other processes (via UDP broadcast) of new data.
• rx_gui.py - Displays last received image, as commanded by rx_ssdv.py via UDP.
• tx_picam.py - TODO.

Testing Scripts

• Run python compress_test_images.py from within ./test_images/ to produce the set of test ssdv-compressed files.

TX Testing

• tx_test_images.py transmits a stream of test images out of the RPi UART. Check the top of the file for settings.
• This script can also be used to produce a one-char-per-bit output, which is what would be seen by the modulator.

RX Testing

• rx_tester.py produces a stream of packets on stdout, as would be received from the fsk_demod modem (from codec2 - still under development).
• Run python rx_tester.py | python rx_ssdv.py to feed these test packets into the command-line ssdv rx script.
• add --partialupdate N to the above command to have rx_gui.py update every N received packets.