From 01fc7fb844cc394c373a14ca427f7c411f8c376d Mon Sep 17 00:00:00 2001
From: Robert <3704942+JasonRJ@users.noreply.github.com>
Date: Wed, 23 Feb 2022 11:41:29 -0500
Subject: [PATCH 1/5] Add method to support SX128x Frequency Error of last
 received LoRa or Ranging packet.  Updated SX128x receive examples.

---
 .../SX128x/SX128x_Receive/SX128x_Receive.ino  |  6 ++++
 .../SX128x_Receive_Interrupt.ino              |  6 ++++
 src/modules/SX128x/SX128x.cpp                 | 33 +++++++++++++++++++
 src/modules/SX128x/SX128x.h                   |  7 ++++
 4 files changed, 52 insertions(+)

diff --git a/examples/SX128x/SX128x_Receive/SX128x_Receive.ino b/examples/SX128x/SX128x_Receive/SX128x_Receive.ino
index 47c6c63b..28dc8047 100644
--- a/examples/SX128x/SX128x_Receive/SX128x_Receive.ino
+++ b/examples/SX128x/SX128x_Receive/SX128x_Receive.ino
@@ -85,6 +85,12 @@ void loop() {
     Serial.print(radio.getSNR());
     Serial.println(F(" dB"));
 
+    // print the Frequency Error
+    // of the last received packet
+    Serial.print(F("[SX1280] Frequency Error:\t"));
+    Serial.print(radio.getFrequencyError());
+    Serial.println(F(" Hz"));
+
   } else if (state == RADIOLIB_ERR_RX_TIMEOUT) {
     // timeout occurred while waiting for a packet
     Serial.println(F("timeout!"));
diff --git a/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino b/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino
index 274121df..77d452c6 100644
--- a/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino
+++ b/examples/SX128x/SX128x_Receive_Interrupt/SX128x_Receive_Interrupt.ino
@@ -136,6 +136,12 @@ void loop() {
       Serial.print(radio.getSNR());
       Serial.println(F(" dB"));
 
+      // print the Frequency Error
+      // of the last received packet
+      Serial.print(F("[SX1280] Frequency Error:\t"));
+      Serial.print(radio.getFrequencyError());
+      Serial.println(F(" Hz"));
+
     } else if (state == RADIOLIB_ERR_CRC_MISMATCH) {
       // packet was received, but is malformed
       Serial.println(F("CRC error!"));
diff --git a/src/modules/SX128x/SX128x.cpp b/src/modules/SX128x/SX128x.cpp
index 972e6ffc..a59572e4 100644
--- a/src/modules/SX128x/SX128x.cpp
+++ b/src/modules/SX128x/SX128x.cpp
@@ -1064,6 +1064,39 @@ float SX128x::getSNR() {
   }
 }
 
+double SX128x::getFrequencyError() {
+    // check active modem
+    uint8_t modem = getPacketType();
+    if (!((modem == RADIOLIB_SX128X_PACKET_TYPE_LORA) || (modem == RADIOLIB_SX128X_PACKET_TYPE_RANGING))) {
+        return (0.0);
+    }
+
+    uint8_t efeRaw[3] = {0};
+    // read the raw frequency error register values
+    int16_t state = readRegister(RADIOLIB_SX128X_REG_FEI_MSB, &efeRaw[0], 1);
+    RADIOLIB_ASSERT(state);
+    state = readRegister(RADIOLIB_SX128X_REG_FEI_MID, &efeRaw[1], 1);
+    RADIOLIB_ASSERT(state);
+    state = readRegister(RADIOLIB_SX128X_REG_FEI_LSB, &efeRaw[2], 1);
+    RADIOLIB_ASSERT(state);
+    uint32_t efe = ((uint32_t) efeRaw[0] << 16) | ((uint32_t) efeRaw[1] << 8) | efeRaw[2];
+    efe &= 0x0FFFFF;
+
+    double error;
+
+    // check the first bit
+    if (efe & 0x80000) {
+        // frequency error is negative
+        efe |= (uint32_t) 0xFFF00000;
+        efe = ~efe + 1;
+        error = 1.55 * (double) efe / (1600.0 / (double) _bwKhz) * -1.0;
+    } else {
+        error = 1.55 * (double) efe / (1600.0 / (double) _bwKhz);
+    }
+
+    return (error);
+}
+
 size_t SX128x::getPacketLength(bool update) {
   (void)update;
   uint8_t rxBufStatus[2] = {0, 0};
diff --git a/src/modules/SX128x/SX128x.h b/src/modules/SX128x/SX128x.h
index 9f258bb1..cf358c74 100644
--- a/src/modules/SX128x/SX128x.h
+++ b/src/modules/SX128x/SX128x.h
@@ -727,6 +727,13 @@ class SX128x: public PhysicalLayer {
     */
     float getSNR();
 
+    /*!
+      \brief Gets frequency error of the latest received packet.
+
+      \returns Frequency error in Hz.
+    */
+    double getFrequencyError();
+
     /*!
       \brief Query modem for the packet length of received payload.
 

From 89de031e187fc37faa3620bea99728b39b8b6392 Mon Sep 17 00:00:00 2001
From: Robert <3704942+JasonRJ@users.noreply.github.com>
Date: Wed, 23 Feb 2022 23:51:54 -0500
Subject: [PATCH 2/5] Add method to support SX128x High Sensitivity Mode.

---
 src/modules/SX128x/SX128x.cpp | 15 +++++++++++++++
 src/modules/SX128x/SX128x.h   |  9 +++++++++
 2 files changed, 24 insertions(+)

diff --git a/src/modules/SX128x/SX128x.cpp b/src/modules/SX128x/SX128x.cpp
index a59572e4..9316eae2 100644
--- a/src/modules/SX128x/SX128x.cpp
+++ b/src/modules/SX128x/SX128x.cpp
@@ -1020,6 +1020,21 @@ int16_t SX128x::setAccessAddress(uint32_t addr) {
   return(SX128x::writeRegister(RADIOLIB_SX128X_REG_ACCESS_ADDRESS_BYTE_3, addrBuff, 4));
 }
 
+int16_t SX128x::setHighSensitivityMode(bool hsm) {
+    // update register
+    uint8_t RxGain = 0;
+    int16_t state = readRegister(RADIOLIB_SX128X_REG_GAIN_MODE, &RxGain, 1);
+    RADIOLIB_ASSERT(state);
+    if (hsm) {
+        RxGain |= 0xC0; // Set bits 6 and 7
+    } else {
+        RxGain &= ~0xC0; // Unset bits 6 and 7
+    }
+    state = writeRegister(RADIOLIB_SX128X_REG_GAIN_MODE, &RxGain, 1);
+    RADIOLIB_ASSERT(state);
+    return(0);
+}
+
 float SX128x::getRSSI() {
   // get packet status
   uint8_t packetStatus[5];
diff --git a/src/modules/SX128x/SX128x.h b/src/modules/SX128x/SX128x.h
index cf358c74..5c18d6d1 100644
--- a/src/modules/SX128x/SX128x.h
+++ b/src/modules/SX128x/SX128x.h
@@ -713,6 +713,15 @@ class SX128x: public PhysicalLayer {
     */
     int16_t setAccessAddress(uint32_t addr);
 
+/*!
+  \brief Enables or disables receiver high sensitivity mode.
+
+  \param True to enable and false to disable.
+
+  \returns 0
+*/
+    int16_t setHighSensitivityMode(bool hsm = false);
+
     /*!
       \brief Gets RSSI (Recorded Signal Strength Indicator) of the last received packet.
 

From da0cd455c93f31fe10910c65979190feffb4c822 Mon Sep 17 00:00:00 2001
From: Robert <3704942+JasonRJ@users.noreply.github.com>
Date: Wed, 23 Feb 2022 23:58:56 -0500
Subject: [PATCH 3/5] Add method to support SX128x Manual Gain Mode.

---
 src/modules/SX128x/SX128x.cpp | 33 +++++++++++++++++++++++++++++++++
 src/modules/SX128x/SX128x.h   |  9 +++++++++
 2 files changed, 42 insertions(+)

diff --git a/src/modules/SX128x/SX128x.cpp b/src/modules/SX128x/SX128x.cpp
index 9316eae2..a9241716 100644
--- a/src/modules/SX128x/SX128x.cpp
+++ b/src/modules/SX128x/SX128x.cpp
@@ -1035,6 +1035,39 @@ int16_t SX128x::setHighSensitivityMode(bool hsm) {
     return(0);
 }
 
+int16_t SX128x::setGainControl(uint8_t gain) {
+    // update registers
+    uint8_t ManualGainSetting = 0;
+    int16_t state = readRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_CONTROL_ENABLE_2, &ManualGainSetting, 1);
+    RADIOLIB_ASSERT(state);
+    uint8_t LNAGainValue = 0;
+    state = readRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_SETTING, &LNAGainValue, 1);
+    RADIOLIB_ASSERT(state);
+    uint8_t LNAGainControl = 0;
+    state = readRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_CONTROL_ENABLE_1, &LNAGainControl, 1);
+    RADIOLIB_ASSERT(state);
+    if (gain > 0 && gain < 14) {
+        // Set manual gain
+        ManualGainSetting &= ~0x01; // Set bit 0 to 0 (Enable Manual Gain Control)
+        LNAGainValue &= 0xF0; // Bits 0, 1, 2 and 3 to 0
+        LNAGainValue |= gain; // Set bits 0, 1, 2 and 3 to Manual Gain Setting (1-13)
+        LNAGainControl |= 0x80; // Set bit 7 to 1 (Enable Manual Gain Control)
+    } else {
+        // Set automatic gain if 0 or out of range
+        ManualGainSetting |= 0x01; // Set bit 0 to 1 (Enable Automatic Gain Control)
+        LNAGainValue &= 0xF0; // Bits 0, 1, 2 and 3 to 0
+        LNAGainValue |= 0x0A; // Set bits 0, 1, 2 and 3 to Manual Gain Setting (1-13)
+        LNAGainControl = 0x4D; // Set bit 7 to 0 (Enable Automatic Gain Control)
+    }
+    state = writeRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_CONTROL_ENABLE_2, &ManualGainSetting, 1);
+    RADIOLIB_ASSERT(state);
+    state = writeRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_SETTING, &LNAGainValue, 1);
+    RADIOLIB_ASSERT(state);
+    state = writeRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_CONTROL_ENABLE_1, &LNAGainControl, 1);
+    RADIOLIB_ASSERT(state);
+    return(0);
+}
+
 float SX128x::getRSSI() {
   // get packet status
   uint8_t packetStatus[5];
diff --git a/src/modules/SX128x/SX128x.h b/src/modules/SX128x/SX128x.h
index 5c18d6d1..2537fe43 100644
--- a/src/modules/SX128x/SX128x.h
+++ b/src/modules/SX128x/SX128x.h
@@ -722,6 +722,15 @@ class SX128x: public PhysicalLayer {
 */
     int16_t setHighSensitivityMode(bool hsm = false);
 
+    /*!
+      \brief Enables or disables receiver manual gain control.
+
+      \param Gain 0 automatic gain; 1 minimum gain to 13 maximum gain.
+
+      \returns \ref status_codes
+    */
+    int16_t setGainControl(uint8_t gain = 0);
+
     /*!
       \brief Gets RSSI (Recorded Signal Strength Indicator) of the last received packet.
 

From ff43d95afa4d74176f6b2532989ac5b805325f53 Mon Sep 17 00:00:00 2001
From: Robert <3704942+JasonRJ@users.noreply.github.com>
Date: Thu, 24 Feb 2022 00:29:51 -0500
Subject: [PATCH 4/5] Cleaned up formatting in header.  Changed assigned value
 to set only the bit indicated in the documentation.

---
 src/modules/SX128x/SX128x.cpp |  2 +-
 src/modules/SX128x/SX128x.h   | 12 ++++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/modules/SX128x/SX128x.cpp b/src/modules/SX128x/SX128x.cpp
index a9241716..5f5ac79e 100644
--- a/src/modules/SX128x/SX128x.cpp
+++ b/src/modules/SX128x/SX128x.cpp
@@ -1057,7 +1057,7 @@ int16_t SX128x::setGainControl(uint8_t gain) {
         ManualGainSetting |= 0x01; // Set bit 0 to 1 (Enable Automatic Gain Control)
         LNAGainValue &= 0xF0; // Bits 0, 1, 2 and 3 to 0
         LNAGainValue |= 0x0A; // Set bits 0, 1, 2 and 3 to Manual Gain Setting (1-13)
-        LNAGainControl = 0x4D; // Set bit 7 to 0 (Enable Automatic Gain Control)
+        LNAGainControl &= ~0x80; // Set bit 7 to 0 (Enable Automatic Gain Control)
     }
     state = writeRegister(RADIOLIB_SX128X_REG_MANUAL_GAIN_CONTROL_ENABLE_2, &ManualGainSetting, 1);
     RADIOLIB_ASSERT(state);
diff --git a/src/modules/SX128x/SX128x.h b/src/modules/SX128x/SX128x.h
index 2537fe43..b86c3984 100644
--- a/src/modules/SX128x/SX128x.h
+++ b/src/modules/SX128x/SX128x.h
@@ -713,13 +713,13 @@ class SX128x: public PhysicalLayer {
     */
     int16_t setAccessAddress(uint32_t addr);
 
-/*!
-  \brief Enables or disables receiver high sensitivity mode.
+    /*!
+      \brief Enables or disables receiver high sensitivity mode.
 
-  \param True to enable and false to disable.
+      \param True to enable and false to disable.
 
-  \returns 0
-*/
+      \returns 0
+    */
     int16_t setHighSensitivityMode(bool hsm = false);
 
     /*!
@@ -727,7 +727,7 @@ class SX128x: public PhysicalLayer {
 
       \param Gain 0 automatic gain; 1 minimum gain to 13 maximum gain.
 
-      \returns \ref status_codes
+      \returns 0
     */
     int16_t setGainControl(uint8_t gain = 0);
 

From 89f202ce6a1fcc0ab4906ecd6d68b8b87e94cb9e Mon Sep 17 00:00:00 2001
From: Robert <3704942+JasonRJ@users.noreply.github.com>
Date: Sat, 26 Feb 2022 18:44:05 -0500
Subject: [PATCH 5/5] Changed method to return float instead of double.  All
 calculations within the method also use float instead of double.  Results of
 the method do not seem to be effected.

---
 src/modules/SX128x/SX128x.cpp | 8 ++++----
 src/modules/SX128x/SX128x.h   | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/modules/SX128x/SX128x.cpp b/src/modules/SX128x/SX128x.cpp
index 5f5ac79e..3bc66b89 100644
--- a/src/modules/SX128x/SX128x.cpp
+++ b/src/modules/SX128x/SX128x.cpp
@@ -1112,7 +1112,7 @@ float SX128x::getSNR() {
   }
 }
 
-double SX128x::getFrequencyError() {
+float SX128x::getFrequencyError() {
     // check active modem
     uint8_t modem = getPacketType();
     if (!((modem == RADIOLIB_SX128X_PACKET_TYPE_LORA) || (modem == RADIOLIB_SX128X_PACKET_TYPE_RANGING))) {
@@ -1130,16 +1130,16 @@ double SX128x::getFrequencyError() {
     uint32_t efe = ((uint32_t) efeRaw[0] << 16) | ((uint32_t) efeRaw[1] << 8) | efeRaw[2];
     efe &= 0x0FFFFF;
 
-    double error;
+    float error;
 
     // check the first bit
     if (efe & 0x80000) {
         // frequency error is negative
         efe |= (uint32_t) 0xFFF00000;
         efe = ~efe + 1;
-        error = 1.55 * (double) efe / (1600.0 / (double) _bwKhz) * -1.0;
+        error = 1.55 * (float) efe / (1600.0 / (float) _bwKhz) * -1.0;
     } else {
-        error = 1.55 * (double) efe / (1600.0 / (double) _bwKhz);
+        error = 1.55 * (float) efe / (1600.0 / (float) _bwKhz);
     }
 
     return (error);
diff --git a/src/modules/SX128x/SX128x.h b/src/modules/SX128x/SX128x.h
index b86c3984..18f12f72 100644
--- a/src/modules/SX128x/SX128x.h
+++ b/src/modules/SX128x/SX128x.h
@@ -750,7 +750,7 @@ class SX128x: public PhysicalLayer {
 
       \returns Frequency error in Hz.
     */
-    double getFrequencyError();
+    float getFrequencyError();
 
     /*!
       \brief Query modem for the packet length of received payload.