kopia lustrzana https://github.com/F5OEO/WsprryPi
Working version with command line options.
Added NTP based frequency calibration, test tone generation, precise TX symbol timing, precise frequency generation.master
James Peroulas
rodzic
eac72752e5
commit
2c96a1df04
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@ -0,0 +1,15 @@
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Install required packages:
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sudo apt-get install git g++ make grep mawk ntp
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Get code/ compile:
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rm -rf WsprryPi
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git clone https://github.com/JamesP6000/WsprryPi.git
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cd WsprryPi
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make
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Install to /usr/local/bin:
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sudo make install
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Uninstall:
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sudo make uninstall
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@ -0,0 +1,14 @@
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Issues:
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Two users were reporting that the program never stops transmitting, even
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when intervals for disabled tx are programmed. The problem was in both
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cases fixed by flashing a new image on the SD card with a freshly downloaded
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image: 2013-02-09-wheezy-raspbian.zip. No apt-get upgrade or firmware
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upgrade was performed. After this WsprryPi TX was running successfully.
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One user reported his RPi died while in WsprryPi service caused by excessive
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RF voltage (90V) on GPIO4 created by a 100 watts AM transmitter 50ft away
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from the antenna. After the damage exessive current was consumed by RPi (1.1A
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from 5V supply), caused by short-circuiting in the 3.3V logic of the BCM2835
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SOC. On his replacement RPi, he is planning to add galvanic isolation and
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buffering.
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@ -0,0 +1,13 @@
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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272
README
272
README
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@ -1,122 +1,208 @@
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Raspberry Pi bareback LF/MF/HF/VHF WSPR transmitter <pe1nnz@amsat.org>
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Raspberry Pi bareback LF/MF/HF/VHF WSPR transmitter
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Makes a very simple WSPR beacon from your RasberryPi by connecting GPIO
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port to Antanna (and LPF), operates on LF, MF, HF and VHF bands from
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0 to 250 MHz.
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Makes a very simple WSPR beacon from your RasberryPi by connecting GPIO
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port to Antenna (and LPF), operates on LF, MF, HF and VHF bands from
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0 to 250 MHz.
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Credits:
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Credits goes to Oliver Mattos and Oskar Weigl who implemented PiFM [1]
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based on the idea of exploiting RPi DPLL as FM transmitter. Dan MD1CLV
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combined this effort with WSPR encoding algorithm from F8CHK, resulting
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in WsprryPi a WSPR beacon for LF and MF bands. Guido PE1NNZ extended
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this effort with DMA based PWM modulation of fractional divider that was
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part of PiFM, allowing to operate the WSPR beacon also on HF and VHF bands.
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In addition time-synchronisation and double amount of power output was
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implemented.
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******
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Installation / update:
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******
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sudo apt-get install git
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git clone https://github.com/JamesP6000/WsprryPi.git
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cd WsprryPi
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make
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[1] PiFM code from http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter
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See the accompanying BUILD file for more details.
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To use:
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******
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Usage: (WSPR --help output):
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******
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Usage:
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wspr [options] callsign locator tx_pwr_dBm f1 <f2> <f3> ...
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OR
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wspr [options] --test-tone f
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Options:
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-h --help
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Print out this help screen.
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-p --ppm ppm
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Known PPM correction to 19.2MHz RPi nominal crystal frequency.
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-s --self-calibration
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Query ntpd before every transmission to obtain the PPM error of the xtal.
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-r --repeat
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Repeatedly, and in order, transmit on all the specified freqs.
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-x --terminate <n>
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Terminate after n transmissions have been completed.
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-o --offset
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Add a random frequency offset to each transmission:
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+/- 80 Hz for WSPR
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+/- 8 Hz for WSPR-15
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-t --test-tone freq
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Simply output a test tone and the specified frequency. Only used
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for debugging and to verify calibration.
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-n --no-delay
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Transmit immediately, do not wait for a WSPR TX window. Used
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for testing only.
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Frequencies can be specified either as an absolute TX carrier frequency, or
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using one of the following strings. If a string is used, the transmission
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will happen in the middle of the WSPR region of the selected band.
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LF LF-15 MF MF-15 160m 160m-15 80m 60m 40m 30m 20m 17m 15m 12m 10m 6m 4m 2m
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<B>-15 indicates the WSPR-15 region of band <B>.
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Transmission gaps can be created by specifying a TX frequency of 0
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******
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Radio licensing / RF:
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******
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In order to transmit legally, a HAM Radio License is REQUIRED for running
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this experiment. The output is a square wave so a low pass filter is REQUIRED.
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Connect a low-pass filter (via decoupling C) to GPIO4 (GPCLK0) and Ground pin
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of your Raspberry Pi, connect an antenna to the LPF. The GPIO4 and GND pins
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are found on header P1 pin 7 and 9 respectively, the pin closest to P1 label
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is pin 1 and its 3rd and 4th neighbour is pin 7 and 9 respectively, see this
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is pin 1 and its 3rd and 4th neighbour is pin 7 and 9 respectively. See this
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link for pin layout: http://elinux.org/RPi_Low-level_peripherals Examples of
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low-pass filters can be found here: http://www.gqrp.com/harmonic_filters.pdf
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The expected power output is 10mW (+10dBm) in a 50 Ohm load. This looks
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neglible, but when connected to a simple dipole antenna this may result in
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reception reports ranging up to several thousands of kilometers.
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Example of low-pass filters here: http://www.gqrp.com/harmonic_filters.pdf
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As the Raspberry Pi does not attenuate ripple and noise components from the
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5V USB power supply, it is RECOMMENDED to use a regulated supply that has
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sufficient ripple supression. Supply ripple might be seen as mixing products
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products centered around the transmit carrier typically at 100/120Hz.
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This software is using system time to determine the start of a WSPR
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transmissions, so keep the system time synchronised within 1sec precision,
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i.e. use NTP network time synchronisation or set time manually with date
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command. A WSPR broadcast starts on even minute and takes 2 minutes for WSPR-2
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or starts at :00,:15,:30,:45 and takes 15 minutes for WSPR-15. It contains
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a callsign, 4-digit Maidenhead square locator and transmission power.
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Reception reports can be viewed on Weak Signal Propagation Reporter Network
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at: http://wsprnet.org/drupal/wsprnet/spots
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Frequency calibration is REQUIRED to ensure that the WSPR-2 transmission occurs
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within the 200 Hz narrow band. The reference crystal on your RPi might have
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an frequency error (which in addition is temp. dependent -1.3Hz/degC @10MHz).
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To calibrate, the frequency might be manually corrected on the command line
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or by changing the F_XTAL value in the code. A practical way to calibrate
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is to tune the transmitter on the same frequency of a medium wave AM broadcast
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station; keep tuning until zero beat (the constant audio tone disappears when
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the transmitter is exactly on the same frequency as the broadcast station),
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and determine the frequency difference with the broadcast station. This is
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the frequency error that can be applied for correction while tuning on a WSPR
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frequency. Do not overclock your RPi as it may make the clock unreliable due to
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a dynamic clocking feature.
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DO NOT expose GPIO4 to voltages or currents that are above the specified
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Absolute Maximum limits. GPIO4 outputs a digital clock in 3V3 logic, with a
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maximum current of 16mA. As there is no current protection available and
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a DC component of 1.6V, DO NOT short-circuit or place a resistive (dummy) load
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maximum current of 16mA. As there is no current protection available and a DC
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component of 1.6V, DO NOT short-circuit or place a resistive (dummy) load
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straight on the GPIO4 pin, as it may draw too much current. Instead, use a
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decoupling capacitor to remove DC component when connecting the output
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dummy loads, transformers, antennas, etc. DO NOT expose GPIO4 to electro-
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static voltages or voltages exceeding the 0 to 3.3V logic range; connecting an
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antenna directly to GPIO4 may damage your RPi due to transient voltages such as
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lightning or static buildup as well as RF from other transmitters operating into
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nearby antennas. Therefore it is RECOMMENDED to add some form of isolation, e.g.
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by using a RF transformer, a simple buffer/driver/PA stage, two schottky small
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signal diodes back to back.
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decoupling capacitor to remove DC component when connecting the output dummy
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loads, transformers, antennas, etc. DO NOT expose GPIO4 to electro- static
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voltages or voltages exceeding the 0 to 3.3V logic range; connecting an
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antenna directly to GPIO4 may damage your RPi due to transient voltages such
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as lightning or static buildup as well as RF from other transmitters
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operating into nearby antennas. Therefore it is RECOMMENDED to add some form
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of isolation, e.g. by using a RF transformer, a simple buffer/driver/PA
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stage, two schottky small signal diodes back to back.
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Installation / update:
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Open a terminal and execute the following commands:
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sudo apt-get install git
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rm -rf WsprryPi
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git clone https://github.com/threeme3/WsprryPi.git
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cd WsprryPi
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******
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TX Timing:
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******
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This software is using system time to determine the start of WSPR
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transmissions, so keep the system time synchronised within 1sec precision,
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i.e. use NTP network time synchronisation or set time manually with date
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command. A WSPR broadcast starts on an even minute and takes 2 minutes for
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WSPR-2 or starts at :00,:15,:30,:45 and takes 15 minutes for WSPR-15. It
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contains a callsign, 4-digit Maidenhead square locator and transmission
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power. Reception reports can be viewed on Weak Signal Propagation Reporter
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Network at: http://wsprnet.org/drupal/wsprnet/spots
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Usage:
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sudo ./wspr <[prefix]/callsign[/suffix]> <locator> <power in dBm> [<frequency in Hz> ...]
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e.g.: sudo ./wspr PA/K1JT JO21 10 7040074 0 0 10140174 0 0
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where 0 frequency represents a interval for which TX is disabled,
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wspr-2 or wspr-15 mode selection based on specified frequency.
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******
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Calibration:
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******
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Frequency calibration is REQUIRED to ensure that the WSPR-2 transmission
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occurs within the narrow 200 Hz band. The reference crystal on your RPi might
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have an frequency error (which in addition is temp. dependent -1.3Hz/degC
|
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@10MHz). To calibrate, the frequency might be manually corrected on the
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command line or a PPM correction could be specified on the command line.
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WSPR is used on the following frequencies (local restriction may apply):
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LF 137400 - 137600
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137600 - 137625 (WSPR-15)
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MF 475600 - 475800
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475800 - 475825 (WSPR-15)
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160m 1838000 - 1838200
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1838200 - 1838225 (WSPR-15)
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80m 3594000 - 3594200
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60m 5288600 - 5288800
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40m 7040000 - 7040200
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30m 10140100 - 10140300
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20m 14097000 - 14097200
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17m 18106000 - 18106200
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15m 21096000 - 21096200
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12m 24926000 - 24926200
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10m 28126000 - 28126200
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6m 50294400 - 50294600
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4m 70092400 - 70092600
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2m 144490400 -144490600
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NTP calibration:
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NTP automatically tracks and calculates a PPM frequency correction. If you
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are running NTP on your Pi, you can use the --self-calibration option to
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have this program querry NTP for the latest frequency correction before
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each WSPR transmission. Some residual frequency error may still be present
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due to delays in the NTP measurement loop and this method works best if your
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Pi has been on for a long time, the crystal's temperature has stabilized,
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and the NTP control loop has converged.
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Compile:
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sudo apt-get install gcc
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gcc -lm -std=c99 wspr.c -owspr
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AM calibration:
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A practical way to calibrate is to tune the transmitter on the same frequency
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of a medium wave AM broadcast station; keep tuning until zero beat (the
|
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constant audio tone disappears when the transmitter is exactly on the same
|
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frequency as the broadcast station), and determine the frequency difference
|
||||
with the broadcast station. This is the frequency error that can be applied
|
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for correction while tuning on a WSPR frequency.
|
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|
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Issues:
|
||||
Two users were reporting that the program never stops transmitting, even
|
||||
when intervals for disabled tx are programmed. The problem was in both
|
||||
cases fixed by flashing a new image on the SD card with a freshly downloaded
|
||||
image: 2013-02-09-wheezy-raspbian.zip. No apt-get upgrade or firmware
|
||||
upgrade was performed. After this WsprryPi TX was running successfully.
|
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Suppose your local AM radio station is at 780kHz. Use the --test-tone option
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to produce different tones around 780kHz (eg 780100 Hz) until you can
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successfully zero beat the AM station. If the zero beat tone specified on the
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command line is F, calculate the PPM correction required as:
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ppm=(F/780000-1)*1e6 In the future, specify this value as the argument to the
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--ppm option on the comman line. You can verify that the ppm value has been
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set correction by specifying --test-tone 780000 --ppm <ppm> on the command
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line and confirming that the Pi is still zero beating the AM station.
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|
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One user reported his RPi died while in WsprryPi service caused by excessive
|
||||
RF voltage (90V) on GPIO4 created by a 100 watts AM transmitter 50ft away from
|
||||
the antenna. After the damage exessive current was consumed by RPi (1.1A from
|
||||
5V supply), caused by short-circuiting in the 3.3V logic of the BCM2835 SOC.
|
||||
On his replacement RPi, he is planning to add galvanic isolation and buffering.
|
||||
******
|
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PWM Peripheral:
|
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******
|
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The code uses the RPi PWM peripheral to time the frequency transitions
|
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of the output clock. This peripheral is also used by the RPi sound system
|
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and hence any sound events that occur during a WSPR transmission will
|
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interfere with WSPR transmissions. Sound can be permanently disabled
|
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by editing /etc/modules and commenting out the snd-bcm2835 device.
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|
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******
|
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Example usage:
|
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******
|
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Brief help screen
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wspr --help
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Transmit a constant test tone at 780 kHz.
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sudo wspr --test-tone 780e3
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|
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Using callsign N9NNN, locator EM10, and TX power 33 dBm, transmit a single
|
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WSPR transmission on the 20m band using NTP based frequency offset
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calibration.
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sudo wspr --self-calibration N9NNN EM10 33 20m
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Transmit a WSPR transmission slightly off-center on 30m every 10 minutes for
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a total of 7 transmissions, and using a fixed PPM correction value. sudo
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wspr --repeat --terminate 7 --ppm 43.17 N9NNN EM10 33 10140210 0 0 0 0
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Transmit repeatedly on 40m, use NTP based frequency offset calibration,
|
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and add a random frequency offset to each transmission to minimize collisions
|
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with other transmissions.
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sudo wspr --repeat --offset --self-calibration N9NNN EM10 33 40m
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|
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******
|
||||
Reference documentation:
|
||||
******
|
||||
http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf
|
||||
http://www.scribd.com/doc/127599939/BCM2835-Audio-clocks
|
||||
http://www.scribd.com/doc/101830961/GPIO-Pads-Control2
|
||||
https://github.com/mgottschlag/vctools/blob/master/vcdb/cm.yaml
|
||||
https://www.kernel.org/doc/Documentation/vm/pagemap.txt
|
||||
|
||||
******
|
||||
Credits:
|
||||
******
|
||||
Credits goes to Oliver Mattos and Oskar Weigl who implemented PiFM [1]
|
||||
based on the idea of exploiting RPi DPLL as FM transmitter.
|
||||
|
||||
Dan MD1CLV combined this effort with WSPR encoding algorithm from F8CHK,
|
||||
resulting in WsprryPi a WSPR beacon for LF and MF bands.
|
||||
|
||||
Guido PE1NNZ <pe1nnz@amsat.org> extended this effort with DMA based PWM
|
||||
modulation of fractional divider that was part of PiFM, allowing to operate
|
||||
the WSPR beacon also on HF and VHF bands. In addition time-synchronisation
|
||||
and double amount of power output was implemented.
|
||||
|
||||
James Peroulas <james@peroulas.com> added several command line options, a
|
||||
makefile, improved frequency generation precision so as to be able to
|
||||
precisely generate a tone at a fraction of a Hz, and added a self calibration
|
||||
feature where the code attempts to derrive frequency calibration information
|
||||
from an installed NTP deamon. Furthermore, the TX length of the WSPR symbols
|
||||
is more precise and does not vary based on system load or PWM clock
|
||||
frequency.
|
||||
|
||||
[1] PiFM code from
|
||||
http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter
|
||||
[2] Original WSPR Pi transmitter code by Dan:
|
||||
https://github.com/DanAnkers/WsprryPi
|
||||
[3] Fork created by Guido:
|
||||
https://github.com/threeme3/WsprryPi
|
||||
[4] This fork created by James:
|
||||
https://github.com/JamesP6000/WsprryPi
|
||||
|
||||
|
|
|
|||
13
makefile
13
makefile
|
|
@ -1,2 +1,13 @@
|
|||
default: wspr
|
||||
prefix=/usr/local
|
||||
|
||||
wspr: wspr.cpp
|
||||
g++ -Wall -lm wspr.cpp -owspr
|
||||
|
||||
.PHONY: install
|
||||
install: wspr
|
||||
install -m 0755 wspr $(prefix)/bin
|
||||
|
||||
.PHONY: uninstall
|
||||
uninstall:
|
||||
rm $(prefix)/bin/wspr
|
||||
|
||||
|
|
|
|||
Ładowanie…
Reference in New Issue