From bf061c655ffee2373c90cade51253cf0fe466c8d Mon Sep 17 00:00:00 2001
From: jgromes <jan.gromes@gmail.com>
Date: Thu, 4 Jan 2024 18:30:22 +0100
Subject: [PATCH] [SX126x] Allow custom band calibration

---
 src/modules/SX126x/SX1262.cpp | 6 +++---
 src/modules/SX126x/SX1262.h   | 5 ++++-
 src/modules/SX126x/SX1268.cpp | 6 +++---
 src/modules/SX126x/SX1268.h   | 7 +++++--
 src/modules/SX126x/SX126x.cpp | 2 +-
 5 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/modules/SX126x/SX1262.cpp b/src/modules/SX126x/SX1262.cpp
index b6f68cb4..0bbce30d 100644
--- a/src/modules/SX126x/SX1262.cpp
+++ b/src/modules/SX126x/SX1262.cpp
@@ -51,12 +51,12 @@ int16_t SX1262::setFrequency(float freq) {
   return(setFrequency(freq, true));
 }
 
-int16_t SX1262::setFrequency(float freq, bool calibrate) {
+int16_t SX1262::setFrequency(float freq, bool calibrate, float band) {
   RADIOLIB_CHECK_RANGE(freq, 150.0, 960.0, RADIOLIB_ERR_INVALID_FREQUENCY);
 
-  // calibrate image rejection - assume band to be the selected frequency +- 4 MHz
+  // calibrate image rejection
   if(calibrate) {
-    int16_t state = SX126x::calibrateImage(freq - 4, freq + 4);
+    int16_t state = SX126x::calibrateImage(freq - band, freq + band);
     RADIOLIB_ASSERT(state);
   }
 
diff --git a/src/modules/SX126x/SX1262.h b/src/modules/SX126x/SX1262.h
index f47b1a81..61f8facc 100644
--- a/src/modules/SX126x/SX1262.h
+++ b/src/modules/SX126x/SX1262.h
@@ -75,9 +75,12 @@ class SX1262: public SX126x {
       \brief Sets carrier frequency. Allowed values are in range from 150.0 to 960.0 MHz.
       \param freq Carrier frequency to be set in MHz.
       \param calibrate Run image calibration.
+      \param band Half bandwidth for image calibration. For example,
+      if carrier is 434 MHz and band is set to 4 MHz, then the image will be calibrate
+      for band 430 - 438 MHz. Unused if calibrate is set to false, defaults to 4 MHz
       \returns \ref status_codes
     */
-    int16_t setFrequency(float freq, bool calibrate);
+    int16_t setFrequency(float freq, bool calibrate, float band = 4);
 
     /*!
       \brief Sets output power. Allowed values are in range from -9 to 22 dBm.
diff --git a/src/modules/SX126x/SX1268.cpp b/src/modules/SX126x/SX1268.cpp
index 8aad25b7..7f14e9fa 100644
--- a/src/modules/SX126x/SX1268.cpp
+++ b/src/modules/SX126x/SX1268.cpp
@@ -52,12 +52,12 @@ int16_t SX1268::setFrequency(float freq) {
 }
 
 /// \todo integers only (all modules - frequency, data rate, bandwidth etc.)
-int16_t SX1268::setFrequency(float freq, bool calibrate) {
+int16_t SX1268::setFrequency(float freq, bool calibrate, float band) {
   RADIOLIB_CHECK_RANGE(freq, 410.0, 810.0, RADIOLIB_ERR_INVALID_FREQUENCY);
 
-  // calibrate image rejection - assume band to be the selected frequency +- 4 MHz
+  // calibrate image rejection
   if(calibrate) {
-    int16_t state = SX126x::calibrateImage(freq - 4, freq + 4);
+    int16_t state = SX126x::calibrateImage(freq - band, freq + band);
     RADIOLIB_ASSERT(state);
   }
 
diff --git a/src/modules/SX126x/SX1268.h b/src/modules/SX126x/SX1268.h
index 08b3eb41..f3f61dc8 100644
--- a/src/modules/SX126x/SX1268.h
+++ b/src/modules/SX126x/SX1268.h
@@ -71,12 +71,15 @@ class SX1268: public SX126x {
     int16_t setFrequency(float freq);
 
     /*!
-      \brief Sets carrier frequency. Allowed values are in range from 410.0 to 810.0 MHz.
+      \brief Sets carrier frequency. Allowed values are in range from 150.0 to 960.0 MHz.
       \param freq Carrier frequency to be set in MHz.
       \param calibrate Run image calibration.
+      \param band Half bandwidth for image calibration. For example,
+      if carrier is 434 MHz and band is set to 4 MHz, then the image will be calibrate
+      for band 430 - 438 MHz. Unused if calibrate is set to false, defaults to 4 MHz
       \returns \ref status_codes
     */
-    int16_t setFrequency(float freq, bool calibrate);
+    int16_t setFrequency(float freq, bool calibrate, float band = 4);
 
     /*!
       \brief Sets output power. Allowed values are in range from -9 to 22 dBm.
diff --git a/src/modules/SX126x/SX126x.cpp b/src/modules/SX126x/SX126x.cpp
index e2ffdb74..59d4e764 100644
--- a/src/modules/SX126x/SX126x.cpp
+++ b/src/modules/SX126x/SX126x.cpp
@@ -1836,7 +1836,7 @@ int16_t SX126x::setRfFrequency(uint32_t frf) {
 }
 
 int16_t SX126x::calibrateImage(float freqMin, float freqMax) {
-  uint8_t data[] = { (uint8_t)floor((freqMin - 1.0f) / 4.0f), (uint8_t)floor((freqMax - 1.0f) / 4.0f) };
+  uint8_t data[] = { (uint8_t)floor((freqMin - 1.0f) / 4.0f), (uint8_t)ceil((freqMax + 1.0f) / 4.0f) };
   int16_t state = this->mod->SPIwriteStream(RADIOLIB_SX126X_CMD_CALIBRATE_IMAGE, data, 2);
 
   // if something failed, show the device errors