WSPR related code snippets and tools
Several tools based on online sources for implementing wspr on raspberry pi and arduino
Credits:
Wspr encoding portion is adapted from james [4] & Guido PE1NNZ [3] Oliver Mattos and Oskar Weigl who implemented PiFM [1] 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. Michael Tatarinov for adding a patch to get PPM info directly from the kernel.
[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] https://github.com/JamesP6000/WsprryPi