From 31d84067068c2ce1c9970030f1e19f848b56258f Mon Sep 17 00:00:00 2001
From: erikkaashoek <erik@kaashoek.com>
Date: Thu, 11 Mar 2021 08:40:21 +0100
Subject: [PATCH] Optimize modulation calibration

---
 main.c    | 41 +++++++----------------------------------
 nanovna.h |  2 +-
 sa_core.c | 11 +++++++++++
 3 files changed, 19 insertions(+), 35 deletions(-)

diff --git a/main.c b/main.c
index e5a32f7..9d9bef4 100644
--- a/main.c
+++ b/main.c
@@ -993,9 +993,9 @@ config_t config = {
   .high_correction_frequency = { 240000000, 280000000, 300000000, 400000000, 500000000, 600000000, 700000000, 800000000, 900000000, 960000000 },
   .high_correction_value = { 0, 0, 0, 0, 0.0, 0, 0, 0, 0, 0 },
   .setting_frequency_10mhz = 10000000,
-  .cor_am = -10,
-  .cor_wfm = -18,
-  .cor_nfm = -18,
+  .cor_am = 0,// -10,
+  .cor_wfm = 0, //-18,
+  .cor_nfm = 0, //-18,
   .ext_zero_level = 128,
 #endif
 #ifdef TINYSA4
@@ -2967,42 +2967,15 @@ int main(void)
 
   chThdCreateStatic(waThread1, sizeof(waThread1), NORMALPRIO-1, Thread1, NULL);
 
-#ifdef TINYSA4
-  reset_settings(M_LOW);
+  reset_settings(M_LOW);                        // Calibrate the modulation frequencies
   set_mode(M_GENLOW);
-  set_sweep_frequency(ST_CENTER, (freq_t)30000000);
   set_sweep_frequency(ST_SPAN, (freq_t)0);
   in_selftest = true;
-
-  if (config.cor_am == 0) {
-    setting.modulation = MO_AM;
-    setting.modulation_frequency = 5000;
-    config.cor_am = 0;
-    perform(false,0, 30000000, false);
-    perform(false,1, 30000000, false);
-    config.cor_am = -(start_of_sweep_timestamp - (ONE_SECOND_TIME / setting.modulation_frequency))/8;
-  }
-
-  if (config.cor_nfm == 0) {
-    setting.modulation = MO_NFM;
-    setting.modulation_frequency = 5000;
-    config.cor_nfm = 0;
-    perform(false,0, 30000000, false);
-    perform(false,1, 30000000, false);
-    config.cor_nfm = -(start_of_sweep_timestamp - (ONE_SECOND_TIME / setting.modulation_frequency))/8;
-  }
-
-  if (config.cor_wfm == 0) {
-    setting.modulation = MO_WFM;
-    setting.modulation_frequency = 5000;
-    config.cor_wfm = 0;
-    perform(false,0, 30000000, false);
-    perform(false,1, 30000000, false);
-    config.cor_wfm = -(start_of_sweep_timestamp - (ONE_SECOND_TIME / setting.modulation_frequency))/8;
-  }
+  calibrate_modulation(MO_AM, &config.cor_am);
+  calibrate_modulation(MO_NFM, &config.cor_nfm);
+  calibrate_modulation(MO_WFM, &config.cor_wfm);
   in_selftest = false;
   reset_settings(M_LOW);
-#endif
 
 
   while (1) {
diff --git a/nanovna.h b/nanovna.h
index 9543618..ee11fae 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -1076,7 +1076,7 @@ typedef struct properties {
 
 //sizeof(properties_t) == 0x1200
 
-#define CONFIG_MAGIC 0x434f4e4A /* 'CONF' */
+#define CONFIG_MAGIC 0x434f4e4b /* 'CONF' */
 
 extern int16_t lastsaveid;
 //extern properties_t *active_props;
diff --git a/sa_core.c b/sa_core.c
index 7a6160c..ce837fc 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -4697,6 +4697,17 @@ void reset_calibration(void)
   config.low_level_offset = 100;
 }
 
+void calibrate_modulation(int modulation, int8_t *correction)
+{
+  if (*correction == 0) {
+    setting.modulation = modulation;
+    setting.modulation_frequency = 5000;
+    perform(false,0, 30000000, false);
+    perform(false,1, 30000000, false);
+    *correction = -(start_of_sweep_timestamp - (ONE_SECOND_TIME / setting.modulation_frequency))/8;
+  }
+}
+
 #define CALIBRATE_RBWS  1
 const int power_rbw [5] = { 100, 300, 30, 10, 3 };