From b6e498a6d3f05ae8aaf73d772c8eff89b357a801 Mon Sep 17 00:00:00 2001
From: Davide Rovelli <103165301+daviderud@users.noreply.github.com>
Date: Mon, 3 Mar 2025 22:17:56 +0100
Subject: [PATCH] Added different modulations in signal generator

* Added DSB, AM 100% mod index and AM 50% mod index.
* Changed UI.
* Added pulsed CW
---
 firmware/application/apps/ui_siggen.cpp |  2 +-
 firmware/application/apps/ui_siggen.hpp |  3 ++-
 firmware/baseband/proc_siggen.cpp       | 19 ++++++++++++-------
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/firmware/application/apps/ui_siggen.cpp b/firmware/application/apps/ui_siggen.cpp
index 2d4ed3767..428ddc9cf 100644
--- a/firmware/application/apps/ui_siggen.cpp
+++ b/firmware/application/apps/ui_siggen.cpp
@@ -118,7 +118,7 @@ SigGenView::SigGenView(
             symfield_tone.hidden(false);
         }
 
-        if ((v == 0) || (v == 2) || (v == 3)) {  // In Modulation Options CW, QPSK, BPSK we are not using Shapes.
+        if ((v == 0) || (v == 2) || (v == 3) || (v == 7)) {  // In Modulation Options CW, QPSK, BPSK, Pulsed CW we are not using Shapes.
             options_shape.hidden(true);
             text_shape.hidden(true);
         } else {
diff --git a/firmware/application/apps/ui_siggen.hpp b/firmware/application/apps/ui_siggen.hpp
index 593e3e62d..bbeeba28b 100644
--- a/firmware/application/apps/ui_siggen.hpp
+++ b/firmware/application/apps/ui_siggen.hpp
@@ -123,7 +123,8 @@ class SigGenView : public View {
          {"QPSK", 3},
          {"DSB", 4},
          {"AM 100% dep.", 5},
-         {"AM 50% depth", 6}}};
+         {"AM 50% depth", 6},
+         {"Pulse CW 25%", 7}}};
 
     TransmitterView tx_view{
         16 * 16,
diff --git a/firmware/baseband/proc_siggen.cpp b/firmware/baseband/proc_siggen.cpp
index 3f118c253..400a5d570 100644
--- a/firmware/baseband/proc_siggen.cpp
+++ b/firmware/baseband/proc_siggen.cpp
@@ -48,8 +48,7 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
             im = 0;
             tone_phase += tone_delta;  // In BPSK-QSPK we are using to calculate each 1/4 of the periode.
         } else if (modulation == 3) {
-            // Digital QPSK  consecutive 00, 01, 10, 11,00, ...continuous cycle ,2 bits/symbol, at rate of 4 symbols / Freq Tone Periode. not random., without any Pulse shape at the moment .
-
+            // Digital QPSK  consecutive 00, 01, 10, 11,00, ...continuous cycle ,2 bits/symbol, at rate of 4 symbols / Freq Tone Periode. not random., without any Pulse shape at the moment.
             switch (((tone_phase & 0xFF000000) >> 24)) {
                 case 0 ... 63:  // equivalent to 1/4 of total 360º degrees.
                     /* "00" */
@@ -62,7 +61,6 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
                     re = (sine_table_i8[96]);       // symbol-phasor 135º
                     im = (sine_table_i8[96 + 64]);  // 96 index   = 32 + 256/4
                     break;
-                    break;
 
                 case 128 ... 191:
                     /* "10" */
@@ -80,8 +78,15 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
                     break;
             }
             tone_phase += tone_delta;  // In BPSK-QSPK we are using to calculate each 1/4 of the periode.
-
-        } else {  // Other modulations: FM, DSB, AM
+        } else if (modulation == 7) {
+            // Pulsed CW, 25% duty cycle.
+            if (tone_phase < 1073741824)  // 1073741824 = 2^32*(25/100)
+                re = 127;
+            else
+                re = 0;
+            im = 0;
+            tone_phase += tone_delta;  // In Pulsed CW we are using to calculate each periode.
+        } else {                       // Other modulations: FM, DSB, AM
             if (tone_shape == 0) {
                 // Sine
                 sample = (sine_table_i8[(tone_phase & 0xFF000000) >> 24]);
@@ -141,12 +146,12 @@ void SigGenProcessor::execute(const buffer_c8_t& buffer) {
 
             } else if (modulation == 5) {
                 // Do AM modulation (100% mod index)
-                re = (127 >> 1) + (sample >> 1);
+                re = 64 + (sample >> 1);  // 64 = 127 - (127 >> 1): carrier level without modulating signal
                 im = 0;
 
             } else if (modulation == 6) {
                 // Do AM modulation (50% mod index)
-                re = 95 + (sample >> 2);
+                re = 96 + (sample >> 2);  // 96 = 127 - (127 >> 2): carrier level without modulating signal
                 im = 0;
             }
         }