Add WSPR TX to eval-clock-cw-tx

1 files changed, 27 insertions, 2 deletions

diff --git a/sw/eval-clock-cw-tx/README.md b/sw/eval-clock-cw-tx/README.md
index 5a22503..c83d0ba 100644
--- a/sw/eval-clock-cw-tx/README.md
+++ b/sw/eval-clock-cw-tx/README.md
@@ -1,5 +1,5 @@
-CW TX firmware for eval-clock
-=============================
+CW TX firmware for eval-clock (2021)
+====================================
 
 Sends CW and FELDHELL https://www.qsl.net/zl1bpu/HELL/Feld.htm
 
@@ -11,6 +11,31 @@ pios are different than on picardy: both Si5351 and display are on same i2c
 PB3 is PTTOUTn
 PB15 is CWOUTn
 
+WSPR beacon (Added 2023)
+------------------------
+
+Let's try to make a WSPR beacon too. Transmit trigger happens with the USB message `wspr\n`, the message itself
+is fixed at compile time.
+
+Centered on 10140.200 kHz plus/minus 100Hz, which is set by USB message too.
+
+From https://swharden.com/software/FSKview/wspr/ :
+Each symbol represents a frequency shift of 12000 / 8192 Hz (1.46Hz) per symbol value giving four-level multi-FSK
+modulation. The transmitted symbol length is the reciprocal of the tone spacing, or approximately 0.683 seconds, so the
+complete message of 162 symbols takes around 110.6 seconds to send and occupies a bandwidth of approximately 6Hz.
+
+12000/8192 = 375/256
+
+Transmission starts one second into an even UTC minute.
+
+HB9EGM JN36 1W is `75 1D C4 F7 A0 17 80`. Tones:
+
+    1, 1, 2, 0, 0, 2, 2, 2, 1, 2, 0, 0, 3, 3, 1, 0, 2, 2, 3, 2, 0, 1, 0, 1, 3, 3, 1, 0, 2, 2, 0, 0, 2, 0, 3, 2, 0, 3, 0,
+    1, 2, 0, 2, 0, 2, 0, 3, 2, 1, 1, 0, 2, 3, 3, 0, 3, 0, 2, 2, 3, 1, 0, 3, 0, 2, 2, 0, 1, 3, 2, 3, 0, 3, 2, 3, 0, 1, 0,
+    0, 3, 0, 0, 1, 2, 1, 3, 0, 2, 2, 1, 3, 2, 3, 0, 3, 2, 0, 0, 3, 2, 0, 0, 0, 2, 3, 2, 0, 1, 2, 0, 1, 1, 1, 0, 3, 1, 2,
+    2, 1, 1, 0, 3, 2, 2, 2, 1, 1, 1, 0, 0, 2, 2, 2, 3, 0, 3, 2, 2, 3, 3, 0, 0, 2, 2, 2, 2, 0, 3, 3, 0, 1, 2, 1, 3, 0, 0,
+    0, 1, 1, 2, 2, 0
+
 
 Programming
 -----------