From d42454e0540434aa8cc757e93fced7f78276557b Mon Sep 17 00:00:00 2001
From: erikkaashoek <erik@kaashoek.com>
Date: Mon, 31 Aug 2020 16:30:26 +0200
Subject: [PATCH] Offset tuning test

---
 sa_core.c | 24 +++++++++++++++++++++---
 si4432.c  | 16 +++++++++++-----
 si4432.h  |  1 +
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/sa_core.c b/sa_core.c
index f75b119..ce4a02c 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -1008,9 +1008,11 @@ void setupSA(void)
 #define OFFSET_LOWER_BOUND 0
 #endif
 
+static uint32_t old_frequency_step;
+
 void set_freq(int V, unsigned long freq)    // translate the requested frequency into a setting of the SI4432
 {
-  if (old_freq[V] == freq)             // Do not change HW if not needed
+  if (old_freq[V] == freq && setting.frequency_step == old_frequency_step)             // Do not change HW if not needed
     return;
 #ifdef __SI4432__
   if (V <= 1) {
@@ -1076,10 +1078,26 @@ void set_freq(int V, unsigned long freq)    // translate the requested frequency
   } else
 #endif
   if (V==ADF4351_LO){
-    ADF4351_set_frequency(V-2,freq,3);
+    if (setting.step_delay_mode == SD_FAST) {        // If in fast scanning mode and NOT SI4432_RX !!!!!!
+      int delta = - (freq - real_old_freq[V]);           // delta grows with increasing freq
+      if (setting.frequency_step < 100000 && 0 < delta && delta < 100000) {
+        SI4463_start_rx(delta / setting.frequency_step); // with increasing delta, set smaller offset
+        freq = 0;
+      } else {
+        SI4463_start_rx(0 / setting.frequency_step);   // Start at maximum positive offset
+      }
+    }
+    if (freq) {
+      ADF4351_set_frequency(V-2,freq,3);
+      real_old_freq[V] = freq;
+    }
   }
   if (V==SI4463_RX) {
-    SI4463_set_freq(freq,1000);
+    if (setting.frequency_step<930000)                  // maximum step size is 937.49kHz
+      SI4463_set_freq(freq,setting.frequency_step);
+    else
+      SI4463_set_freq(freq,1000);
+    old_frequency_step = setting.frequency_step;
   }
 #ifdef __ULTRA_SA__
   else {
diff --git a/si4432.c b/si4432.c
index fa214e8..7a6c4ca 100644
--- a/si4432.c
+++ b/si4432.c
@@ -1213,6 +1213,8 @@ void ADF4351_prep_frequency(int channel, unsigned long freq, int drive)  // freq
 // ------------------------------ SI4463 -------------------------------------
 
 
+#define Npresc 0    // No High performance mode
+
 #include <string.h>
 
 void SI4463_write_byte(uint8_t ADR, uint8_t DATA)
@@ -1394,6 +1396,8 @@ void SI4463_start_rx(uint8_t CHANNEL)
   };
 //retry:
   SI4463_do_api(data, sizeof(data), NULL, 0);
+  my_microsecond_delay(SI4432_offset_delay);
+
 #if 0
   //  my_microsecond_delay(15000);
 //  si446x_state_t s = getState();
@@ -1714,6 +1718,8 @@ static RBW_t RBW_choices[] =
  {SI4463_RBW_850kHz,0,8500},
 };
 
+const int SI4432_RBW_count = ((int)(sizeof(RBW_choices)/sizeof(RBW_t)));
+
 static pureRSSI_t SI4463_RSSI_correction = float_TO_PURE_RSSI(-120);
 
 uint16_t SI4463_force_RBW(int f)
@@ -1731,8 +1737,8 @@ uint16_t SI4463_force_RBW(int f)
   }
   SI4463_start_rx(0);
   my_microsecond_delay(1000);
-  SI4463_RSSI_correction = float_TO_PURE_RSSI(RBW_choices[i].RSSI_correction_x_10 - 1200)/10;  // Set RSSI correction
-  return RBW_choices[i].RBWx10;                                                   // RBW achieved by SI4463 in kHz * 10
+  SI4463_RSSI_correction = float_TO_PURE_RSSI(RBW_choices[f].RSSI_correction_x_10 - 1200)/10;  // Set RSSI correction
+  return RBW_choices[f].RBWx10;                                                   // RBW achieved by SI4463 in kHz * 10
 }
 
 uint16_t SI4463_SET_RBW(uint16_t WISH)  {
@@ -1765,9 +1771,9 @@ void SI4463_set_freq(uint32_t freq, uint32_t step_size)
     Odiv = 13;
     D = 12;
   }
-  int32_t R = (RFout * D) / 26.0 - 1;
+  int32_t R = (RFout * D) / ((Npresc+1)*26.0) - 1;
   float MOD = 520251.0;
-  int32_t  F = (((RFout * D) / 26.0) - R) * MOD;
+  int32_t  F = (((RFout * D) / ((Npresc+1)*26.0)) - R) * MOD;
 
   int   S = (int)(step_size / 14.305);
   if (S == 0) S = 1;
@@ -1816,7 +1822,7 @@ void SI4463_set_freq(uint32_t freq, uint32_t step_size)
   #define RF_MODEM_CLKGEN_BAND_1 0x11, 0x20, 0x01, 0x51, 0x0A
   uint8_t data2[] = {
      0x11, 0x20, 0x01, 0x51,
-     (uint8_t)Odiv
+     (uint8_t)Odiv + (Npresc*0x08)           // 0x08 for high performance mode
   };
   SI4463_do_api(data2, sizeof(data2), NULL, 0);
   SI4463_start_rx(0);
diff --git a/si4432.h b/si4432.h
index 42ded3a..0f3d938 100644
--- a/si4432.h
+++ b/si4432.h
@@ -179,6 +179,7 @@ int16_t Si446x_RSSI(void);
 uint8_t getFRR(uint8_t reg);
 si446x_state_t getState(void);
 void setState(si446x_state_t newState);
+extern const int SI4432_RBW_count;
 extern si446x_info_t SI4463_info;
 void Si446x_getInfo(si446x_info_t* info);
 void SI4463_init(void);