kopia lustrzana https://github.com/projecthorus/wenet
1
Old Notes
Mark Jessop edytuje tę stronę 2022-03-12 16:09:12 +10:30
Some notes that used to be in the main README.
WARNING: The below information is partly outdated. Use the above installation guide.
Main Programs
rx/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 ssdv and telemetry data.rx/rx_gui.py
- Displays last received image, as commanded by rx_ssdv.py via UDP.tx/init_rfm22b.py
- Set RFM22B (attached via SPI to the RPi) into Direct-Asynchronous mode.tx/init_rfm98w.py
- Set RFM98W (attached via SPI to the RPi) into Direct-Asynchronous mode. Note that this requires pySX127x from https://github.com/darksidelemm/pySX127xtx_picam_gps.py
- Captures pictures using the PiCam, overlays GPS data and transmits them.
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.- 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.
Sending/Receiving Images
TX Side
Refer to the instructions here: https://github.com/projecthorus/wenet/wiki/Wenet-TX-Payload-Instructions
RX Side
Refer to the instructions here: https://github.com/projecthorus/wenet/wiki/Wenet-RX-Instructions-(Linux-using-Docker)
RX Tips.
- It is highly recommended to use a preamplifier in front of your RTLSDR to lower the overall noise figure of the system. With a NooElec RTLSDR (R820T2 Tuner) and a HabAmp, we were able to achieve a Minimum-Detectable-Signal (MDS - which we defined as the point where we get no packet errors) of around -112 dBm.
- If needed, the transmit bitrate can be slowed down by editing the defaults in tx_picam.py. You will then have to determine the appropriate parameters for fsk_demod and the preceding filtering/resampling chain to be able to receive this bitrate.