Added comments to RFM22B init code, updated csdr examples for better SNR (tweaked filter parameters).

README.md

@@ -1,18 +1,19 @@
-# HorusHighSpeed
+# Wenet - The Swift One
 Modulator and glue code for the 115kbps 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)
+* SSDV (https://github.com/fsphil/ssdv). The `ssdv` binary needs to be available on the PATH.
+* crcmod (`pip install crcmod`)
 * numpy (for debug output tests)
-* PyQt4 (for SSDV GUI)
+* PyQtGraph & PyQt4 (for FSK Modem Stats and SSDV GUI: `pip install pyqtgraph`)
 
 ## 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.
+* `init_rfm22b.py` - Set RFM22B (attached via SPI to the RPi) into Direct-Asynchronous mode. 
 * `tx_picam.py` - Captures pictures using the PiCam, and transmits them.
 
 ## Testing Scripts
@@ -32,7 +33,7 @@ The transmit side is designed to run on a Raspberry Pi, and the UART (/dev/ttyAM
 * Run either `python tx_picam.py` (might need sudo) or `python tx_test_images.py` on the transmitter Raspberry Pi.
 
 #### IMPORTANT NOTE
-While the transit code requests an output baud rate of 115200 baud from the RPi's UART, the acheived baud rate (due to clock divisors) is actually 115386.843 baud (measured using a frequency counter). All of the resampling within the receive chain needs to be adjusted accordingly.
+While the transit code requests an output baud rate of 115200 baud from the RPi's UART, the acheived baud rate (due to clock divisors) is actually 115386.843 baud (measured using a frequency counter). All of the resampling within the receive chain has been adjusted accordingly.
 
 ### RX Side
 To be able to run a full receive chain, from SDR through to images, you'll need:
@@ -41,7 +42,7 @@ To be able to run a full receive chain, from SDR through to images, you'll need:
  * `svn checkout http://svn.code.sf.net/p/freetel/code/codec2-dev/`
  * `cd codec2-dev && mkdir build-linux && cd build-linux && cmake ../`
  * Build `drs232` using `gcc src/drs232.c -o src/drs232 -Wall`
- * Then copy `src/fsk_demod` and `src/drs232` to this directory. 
+ * Then copy `src/fsk_demod`, `src/drs232` and `octace/fskdemodgui.py` to this directory. 
 
 * A few example gnuradio-companion flow-graphs are in the `grc` directory, for different SDRs. These receive samples from the SDR, demodulate a 500KHz section of spectrum as USB, resamples them to fsbaud*8 (which fsk_demod requires), then presents these samples via a TCP sink, which is acting as a TCP server. You will probably need to modify these to set the appropriate receive frequency.
 
@@ -49,16 +50,16 @@ To be able to run a full receive chain, from SDR through to images, you'll need:
  * In another terminal: `python rx_gui.py`, which will listen via UDP for new images to display.
  * Start the appropriate GNURadio Companion Flowgraph. This will block until a client connects to the TCP Sinks TCP socket on port 9898.
  * Start the FSK modem with:
-  * `nc localhost 9898 | ./fsk_demod 2X 8 923096 115387 - - | ./drs232 - - | python rx_ssdv.py --partialupdate 8`
+  * `nc localhost 9898 | ./fsk_demod 2X 8 923096 115387 - - S 2> >(python fskdemodgui.py) | ./drs232 - - | python rx_ssdv.py --partialupdate 8`
 
 ### RX Without GNURadio
-It's possible to use csdr ( https://github.com/simonyiszk/csdr ) to perform the sideband demodulation and resampling functions:
+It's possible to use csdr (Get it from https://github.com/simonyiszk/csdr ) to perform the sideband demodulation and resampling functions:
 
 Example (RTLSDR):
-`rtl_sdr -s 1000000 -f 441000000 -g 35 - | csdr convert_u8_f | csdr bandpass_fir_fft_cc 0 0.4 0.1 | csdr fractional_decimator_ff 1.08331 | csdr realpart_cf | csdr convert_f_s16 | ./fsk_demod 2X 8 923096 115387 - - | ./drs232 - - | python rx_ssdv.py --partialupdate 8`
+`rtl_sdr -s 1000000 -f 441000000 -g 35 - | csdr convert_u8_f | csdr bandpass_fir_fft_cc 0.1 0.4 0.05 | csdr fractional_decimator_ff 1.08331 | csdr realpart_cf | csdr convert_f_s16 | ./fsk_demod 2X 8 923096 115387 - - S 2> >(python fskdemodgui.py) | ./drs232 - - | python rx_ssdv.py --partialupdate 8`
 
 This gets samples from the rtl_sdr at 1MHz, performs bandpass and fractional decimation options (to get the required Rb*8 sample rate for fsk_demod), then throw away the imaginary part and converts to 16-bit shorts before passing the data to fsk_demod.
 
 Example (AirSpy):
-`airspy_rx -f441.0 -r /dev/stdout -a 2500000 -h 21  | csdr convert_s16_f | csdr bandpass_fir_fft_cc 0 0.2 0.1 | csdr fractional_decimator_ff 2.708277 | csdr realpart_cf | csdr convert_f_s16 | ./fsk_demod 2X 8 923096 115387 - - | ./drs232 - - | python rx_ssdv.py --partialupdate 8`
+`airspy_rx -f441.0 -r /dev/stdout -a 1 -h 21  | csdr convert_s16_f | csdr bandpass_fir_fft_cc 0.025 0.175 0.025 | csdr fractional_decimator_ff 2.708277 | csdr realpart_cf | csdr convert_f_s16 | ./fsk_demod 2X 8 923096 115387 - - S 2> >(python fskdemodgui.py) | ./drs232 - - | python rx_ssdv.py --partialupdate 8`
 

init_rfm22b.py

@@ -251,9 +251,9 @@ class RFM22B(object):
 if __name__ == '__main__':
 	rfm = RFM22B()
 	rfm.set_tx_power(TXPOW.TXPOW_14DBM | 0x08)
-	rfm.set_frequency(441.2E6)
+	rfm.set_frequency(441.2E6) # 441.2MHz.
 	rfm.write_register(REG.GPIO2_CONFIGURATION,0x30) # TX Data In
-	rfm.set_bulk(CONFIGS.REGISTERS,CONFIGS.DIRECT_120K)
+	rfm.set_bulk(CONFIGS.REGISTERS,CONFIGS.DIRECT_120K) # Direct Asynchronous mode, ~120KHz tone spacing.
 	rfm.set_mode(0x09)
 	rfm.close()