kopia lustrzana https://github.com/projecthorus/horusdemodlib
124 wiersze
4.4 KiB
Bash
Executable File
124 wiersze
4.4 KiB
Bash
Executable File
#!/usr/bin/env bash
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#
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# Dual RTTY / Horus Binary Decoder Script
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# Intended for use on Horus flights, with the following payload frequencies:
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# RTTY: 434.650 MHz - Callsign 'HORUS'
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# MFSK: 434.660 MHz - Callsign 'HORUSBINARY'
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#
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# The SDR is tuned 5 kHz below the RTTY frequency, and the frequency estimators are set across the two frequencies.
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# Modem statistics are sent out via a new 'MODEM_STATS' UDP broadcast message every second.
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#
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# Change directory to the horusdemodlib directory.
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# If running as a different user, you will need to change this line
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cd /home/pi/horusdemodlib/
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# Receive requency, in Hz. This is the frequency the SDR is tuned to.
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RXFREQ=434645000
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# Where in the passband we expect to find the RTTY signal, in Hz.
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# For Horus flights, this is on 434.650 MHz, so with a SDR frequency of 434.645 MHz,
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# we expect to find the RTTY signal at approx +5 kHz.
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# Note that the signal must be located ABOVE the centre frequency of the receiver.
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RTTY_SIGNAL=5000
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# Where in the receiver passband we expect to find the Horus Binary (MFSK) signal, in Hz.
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# For Horus flights, this is on 434.660 MHz, so with a SDR frequency of 434.645 MHz,
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# we expect to find the RTTY signal at approx +15 kHz.
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MFSK_SIGNAL=15000
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# Frequency estimator bandwidth. The wider the bandwidth, the more drift and frequency error the modem can tolerate,
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# but the higher the chance that the modem will lock on to a strong spurious signal.
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RXBANDWIDTH=8000
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# RTLSDR Device Selection
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# If you want to use a specific RTLSDR, you can change this setting to match the
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# device identifier of your SDR (use rtl_test to get a list)
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SDR_DEVICE=0
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# Receiver Gain. Set this to 0 to use automatic gain control, otherwise if running a
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# preamplifier, you may want to experiment with different gain settings to optimize
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# your receiver setup.
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# You can find what gain range is valid for your RTLSDR by running: rtl_test
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GAIN=0
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# Bias Tee Enable (1) or Disable (0)
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# NOTE: This uses the -T bias-tee option which is only available on recent versions
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# of rtl-sdr. Check if your version has this option by running rtl_fm --help and looking
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# for it in the option list.
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# If not, you may need to uninstall that version, and then compile from source: https://github.com/osmocom/rtl-sdr
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BIAS=0
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# Receiver PPM offset
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PPM=0
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# Check that the horus_demod decoder has been compiled.
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DECODER=./build/src/horus_demod
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if [ -f "$DECODER" ]; then
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echo "Found horus_demod."
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else
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echo "ERROR - $DECODER does not exist - have you compiled it yet?"
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exit 1
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fi
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# Check that bc is available on the system path.
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if echo "1+1" | bc > /dev/null; then
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echo "Found bc."
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else
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echo "ERROR - Cannot find bc - Did you install it?"
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exit 1
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fi
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# Use a local venv if it exists
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VENV_DIR=venv
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if [ -d "$VENV_DIR" ]; then
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echo "Entering venv."
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source $VENV_DIR/bin/activate
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fi
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# Calculate the frequency estimator limits
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# Note - these are somewhat hard-coded for this dual-RX application.
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RTTY_LOWER=$(echo "$RTTY_SIGNAL - $RXBANDWIDTH/2" | bc)
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RTTY_UPPER=$(echo "$RTTY_SIGNAL + $RXBANDWIDTH/2" | bc)
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RTTY_CENTRE=$(echo "$RXFREQ + $RTTY_SIGNAL" | bc)
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MFSK_LOWER=$(echo "$MFSK_SIGNAL - $RXBANDWIDTH/2" | bc)
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MFSK_UPPER=$(echo "$MFSK_SIGNAL + $RXBANDWIDTH/2" | bc)
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MFSK_CENTRE=$(echo "$RXFREQ + $MFSK_SIGNAL" | bc)
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echo "Using SDR Centre Frequency: $RXFREQ Hz."
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echo "Using RTTY estimation range: $RTTY_LOWER - $RTTY_UPPER Hz"
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echo "Using MFSK estimation range: $MFSK_LOWER - $MFSK_UPPER Hz"
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BIAS_SETTING=""
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if [ "$BIAS" = "1" ]; then
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echo "Enabling Bias Tee."
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BIAS_SETTING=" -T"
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fi
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GAIN_SETTING=""
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if [ "$GAIN" = "0" ]; then
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echo "Using AGC."
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GAIN_SETTING=""
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else
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echo "Using Manual Gain"
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GAIN_SETTING=" -g $GAIN"
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fi
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STATS_SETTING=""
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if [ "$STATS_OUTPUT" = "1" ]; then
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echo "Enabling Modem Statistics."
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STATS_SETTING=" --stats=100"
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fi
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# Start the receive chain.
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# Note that we now pass in the SDR centre frequency ($RXFREQ) and 'target' signal frequency ($RTTY_CENTRE / $MFSK_CENTRE)
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# to enable providing additional metadata to Habitat / Sondehub.
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rtl_fm -M raw -F9 -d $SDR_DEVICE -s 48000 -p $PPM $GAIN_SETTING$BIAS_SETTING -f $RXFREQ | tee >($DECODER -q --stats=5 -g -m RTTY --fsk_lower=$RTTY_LOWER --fsk_upper=$RTTY_UPPER - - | python -m horusdemodlib.uploader --rtty --freq_hz $RXFREQ --freq_target_hz $RTTY_CENTRE ) >($DECODER -q --stats=5 -g -m binary --fsk_lower=$MFSK_LOWER --fsk_upper=$MFSK_UPPER - - | python -m horusdemodlib.uploader --freq_hz $RXFREQ --freq_target_hz $MFSK_CENTRE ) > /dev/null
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