From a31cf3d6f8a99162432c0d73508218dc7a783e19 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Sun, 26 Apr 2020 12:07:10 +0100
Subject: [PATCH] Convert the CTCSS TX tones to Q31 from Q15.

---
 FMCTCSSTX.cpp | 109 ++++++++++++++++++++++++--------------------------
 1 file changed, 53 insertions(+), 56 deletions(-)

diff --git a/FMCTCSSTX.cpp b/FMCTCSSTX.cpp
index 754612a..37241f9 100644
--- a/FMCTCSSTX.cpp
+++ b/FMCTCSSTX.cpp
@@ -23,59 +23,58 @@
 const struct TX_CTCSS_TABLE {
   uint8_t  frequency;
   uint16_t length;
-  q15_t    increment;
+  q31_t    increment;
 } TX_CTCSS_TABLE_DATA[] = {
-  { 67U, 358U,  92},
-  { 69U, 346U,  95},
-  { 71U, 334U,  99},
-  { 74U, 323U, 102},
-  { 77U, 312U, 106},
-  { 79U, 301U, 109},
-  { 82U, 291U, 113},
-  { 85U, 281U, 117},
-  { 88U, 271U, 121},
-  { 91U, 262U, 125},
-  { 94U, 253U, 130},
-  { 97U, 246U, 133},
-  {100U, 240U, 137},
-  {103U, 232U, 142},
-  {107U, 224U, 147},
-  {110U, 216U, 152},
-  {114U, 209U, 157},
-  {118U, 202U, 163},
-  {123U, 195U, 168},
-  {127U, 189U, 174},
-  {131U, 182U, 180},
-  {136U, 176U, 187},
-  {141U, 170U, 193},
-  {146U, 164U, 200},
-  {151U, 159U, 207},
-  {156U, 153U, 214},
-  {159U, 150U, 219},
-  {162U, 148U, 222},
-  {165U, 145U, 226},
-  {167U, 143U, 230},
-  {171U, 140U, 234},
-  {173U, 138U, 238},
-  {177U, 135U, 243},
-  {179U, 133U, 246},
-  {183U, 131U, 251},
-  {186U, 129U, 255},
-  {189U, 126U, 260},
-  {192U, 124U, 264},
-  {196U, 122U, 269},
-  {199U, 120U, 273},
-  {203U, 118U, 278},
-  {206U, 116U, 282},
-  {210U, 114U, 288},
-  {218U, 110U, 298},
-  {225U, 106U, 309},
-  {229U, 105U, 313},
-  {233U, 103U, 319},
-  {241U,  99U, 331},
-  {250U,  96U, 342},
-  {254U,  94U, 347}
-};
+  { 67U, 358U, 5995059},
+  { 69U, 346U, 6200860},
+  { 71U, 334U, 6433504},
+  { 74U, 323U, 6657200},
+  { 77U, 312U, 6889844},
+  { 79U, 301U, 7131436},
+  { 82U, 291U, 7381976},
+  { 85U, 281U, 7641463},
+  { 88U, 271U, 7918846},
+  { 91U, 262U, 8187282},
+  { 94U, 253U, 8482561},
+  { 97U, 246U, 8715205},
+  {100U, 240U, 8947849},
+  {103U, 232U, 9261024},
+  {107U, 224U, 9592094},
+  {110U, 216U, 9923165},
+  {114U, 209U, 10272131},
+  {118U, 202U, 10630045},
+  {123U, 195U, 11005854},
+  {127U, 189U, 11390612},
+  {131U, 182U, 11793265},
+  {136U, 176U, 12213814},
+  {141U, 170U, 12643310},
+  {146U, 164U, 13081755},
+  {151U, 159U, 13547043},
+  {156U, 153U, 14021279},
+  {159U, 150U, 14298662},
+  {162U, 148U, 14513411},
+  {165U, 145U, 14808690},
+  {167U, 143U, 15023438},
+  {171U, 140U, 15327665},
+  {173U, 138U, 15551361},
+  {177U, 135U, 15864536},
+  {179U, 133U, 16097180},
+  {183U, 131U, 16419303},
+  {186U, 129U, 16660894},
+  {189U, 126U, 16991965},
+  {192U, 124U, 17251452},
+  {196U, 122U, 17591471},
+  {199U, 120U, 17850958},
+  {203U, 118U, 18208872},
+  {206U, 116U, 18477308},
+  {210U, 114U, 18853117},
+  {218U, 110U, 19515258},
+  {225U, 106U, 20195295},
+  {229U, 105U, 20499521},
+  {233U, 103U, 20902175},
+  {241U,  99U, 21635898},
+  {250U,  96U, 22396465},
+  {254U,  94U, 22736484}};
 
 const uint8_t CTCSS_TABLE_DATA_LEN = 50U;
 
@@ -105,14 +104,12 @@ uint8_t CFMCTCSSTX::setParams(uint8_t frequency, uint8_t level)
   delete[] m_values;
   m_values = new q15_t[m_length];
 
-  q15_t arg = 0;
+  q31_t arg = 0;
   for (uint16_t i = 0U; i < m_length; i++) {
-    q31_t value = ::arm_sin_q15(arg) * q15_t(level * 13);
+    q31_t value = ::arm_sin_q31(arg) * q15_t(level * 13);
     m_values[i] = q15_t(__SSAT((value >> 15), 16));
 
     arg += entry->increment;
-    if(arg < 0)//did we exceed max value of q15_t and flip over ?
-      arg += 32768;//bring arg back to valid values for ::arm_sin_q15, as per doc it needs to be in the range 0 to 0.99999999 (aka 0 - 32767)
   }
 
   return 0U;