From 95e76f387c4c980ca85960cafb63010f9a504926 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Thu, 16 Apr 2020 21:15:15 +0100
Subject: [PATCH] Complete the CW keyer.

---
 FMCTCSSTX.cpp | 12 +++++-----
 FMKeyer.cpp   | 61 ++++++++++++++++++++++++++++++++++++++++++---------
 FMKeyer.h     |  8 +++++--
 3 files changed, 63 insertions(+), 18 deletions(-)

diff --git a/FMCTCSSTX.cpp b/FMCTCSSTX.cpp
index 0513f13..4c92577 100644
--- a/FMCTCSSTX.cpp
+++ b/FMCTCSSTX.cpp
@@ -24,7 +24,7 @@ const struct CTCSS_TABLE {
   uint8_t  frequency;
   uint16_t length;
   q15_t    increment;
-} CTCSS_TABLE[] = {
+} CTCSS_TABLE_DATA[] = {
   { 67U, 358U,  92},
   { 69U, 346U,  95},
   { 71U, 334U,  99},
@@ -77,7 +77,7 @@ const struct CTCSS_TABLE {
   {254U,  94U, 347}
 };
 
-const uint8_t CTCSS_TABLE_LEN = 50U;
+const uint8_t CTCSS_TABLE_DATA_LEN = 50U;
 
 CFMCTCSSTX::CFMCTCSSTX() :
 m_values(NULL),
@@ -88,11 +88,11 @@ m_n(0U)
 
 uint8_t CFMCTCSSTX::setParams(uint8_t frequency, uint8_t level)
 {
-  struct CTCSS_TABLE* entry = NULL;
+  const CTCSS_TABLE* entry = NULL;
 
-  for (uint8_t i = 0U; i < CTCSS_TABLE_LEN; i++) {
-    if (CTCSS_TABLE[i].frequency == frequency) {
-      entry = CTCSS_TABLE + i;
+  for (uint8_t i = 0U; i < CTCSS_TABLE_DATA_LEN; i++) {
+    if (CTCSS_TABLE_DATA[i].frequency == frequency) {
+      entry = CTCSS_TABLE_DATA + i;
       break;
     }
   }
diff --git a/FMKeyer.cpp b/FMKeyer.cpp
index 56aa3d3..925a484 100644
--- a/FMKeyer.cpp
+++ b/FMKeyer.cpp
@@ -76,18 +76,20 @@ const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02
 #define READ_BIT(p,i)    (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
 
 CFMKeyer::CFMKeyer() :
-m_level(128 * 128),
 m_wanted(false),
-m_running(false),
 m_poBuffer(),
-m_poLen(0U)
+m_poLen(0U),
+m_poPos(0U),
+m_dotLen(0U),
+m_dotPos(0U),
+m_audio(NULL),
+m_audioLen(0U),
+m_audioPos(0U)
 {
 }
 
 uint8_t CFMKeyer::setParams(const char* text, uint8_t speed, uint16_t frequency, uint8_t level)
 {
-  m_level = q15_t(level * 128);
-
   for (uint8_t i = 0U; text[i] != '\0'; i++) {
     for (uint8_t j = 0U; SYMBOL_LIST[j].c != 0U; j++) {
       if (SYMBOL_LIST[j].c == text[i]) {
@@ -107,27 +109,66 @@ uint8_t CFMKeyer::setParams(const char* text, uint8_t speed, uint16_t frequency,
     }
   }
 
+  q15_t value = q15_t(level * 128);
+
+  m_dotLen = 24000U / speed;   // In samples
+
+  m_audioLen = 24000U / frequency; // In samples
+
+  m_audio = new q15_t[m_audioLen];
+
+  for (uint16_t i = 0U; i < m_audioLen; i++) {
+    if (i < (m_audioLen / 2U))
+      m_audio[i] = value;
+    else
+      m_audio[i] = -value;
+  }
+
   return 0U;
 }
 
 void CFMKeyer::getAudio(q15_t* samples, uint8_t length)
 {
-  if (!m_wanted && !m_running)
+  if (!m_wanted)
     return;
+
+  for (uint8_t i = 0U; i < length; i++) {
+    bool b = READ_BIT(m_poBuffer, m_poPos);
+    if (b)
+      samples[i] += m_audio[m_audioPos];
+
+    m_audioPos++;
+    if (m_audioPos >= m_audioLen)
+      m_audioPos = 0U;
+    m_dotPos++;
+    if (m_dotPos >= m_dotLen) {
+      m_dotPos = 0U;
+      m_poPos++;
+      if (m_poPos >= m_poLen) {
+        stop();
+        return;
+      }
+    }
+  }
 }
 
 void CFMKeyer::start()
 {
-  m_wanted = true;
+  m_wanted   = true;
+  m_poPos    = 0U;
+  m_dotPos   = 0U;
+  m_audioPos = 0U;
 }
 
 void CFMKeyer::stop()
 {
-  m_wanted  = false;
-  m_running = false;
+  m_wanted   = false;
+  m_poPos    = 0U;
+  m_dotPos   = 0U;
+  m_audioPos = 0U;
 }
 
 bool CFMKeyer::isRunning() const
 {
-  return m_running;
+  return m_poPos > 0U || m_dotPos > 0U || m_audioPos > 0U;
 }
diff --git a/FMKeyer.h b/FMKeyer.h
index dbcb011..3676522 100644
--- a/FMKeyer.h
+++ b/FMKeyer.h
@@ -35,11 +35,15 @@ public:
   bool isRunning() const;
 
 private:
-  q15_t    m_level;
   bool     m_wanted;
-  bool     m_running;
   uint8_t  m_poBuffer[1000U];
   uint16_t m_poLen;
+  uint16_t m_poPos;
+  uint16_t m_dotLen;
+  uint16_t m_dotPos;
+  q15_t*   m_audio;
+  uint16_t m_audioLen;
+  uint16_t m_audioPos;
 };
 
 #endif