From 842c54849da573e041192db5bb2032f32f7e9ac3 Mon Sep 17 00:00:00 2001
From: jgromes <jan.gromes@gmail.com>
Date: Sat, 13 Jan 2024 13:39:51 +0100
Subject: [PATCH] [SX127x] Added setLowBatteryThreshold (#925)

---
 keywords.txt                  |  1 +
 src/modules/SX127x/SX127x.cpp | 22 ++++++++++++++++++++++
 src/modules/SX127x/SX127x.h   | 26 ++++++++++++++++++--------
 3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/keywords.txt b/keywords.txt
index 065991a09..c68cc5bd0 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -182,6 +182,7 @@ setFifoFullAction	KEYWORD2
 clearFifoFullAction	KEYWORD2
 fifoAdd	KEYWORD2
 fifoGet	KEYWORD2
+setLowBatteryThreshold	KEYWORD2
 
 # RF69-specific
 setAESKey	KEYWORD2
diff --git a/src/modules/SX127x/SX127x.cpp b/src/modules/SX127x/SX127x.cpp
index 38953a145..cdf68ad32 100644
--- a/src/modules/SX127x/SX127x.cpp
+++ b/src/modules/SX127x/SX127x.cpp
@@ -1714,4 +1714,26 @@ float SX127x::getRSSI(bool packet, bool skipReceive, int16_t offset) {
   }
 }
 
+int16_t SX127x::setLowBatteryThreshold(int8_t level, uint32_t pin) {
+  // check disable
+  if(level < 0) {
+    return(this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_LOW_BAT, RADIOLIB_SX127X_LOW_BAT_OFF, 3, 3));
+  }
+
+  // enable detector and set the threshold
+  int16_t state = this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_LOW_BAT, RADIOLIB_SX127X_LOW_BAT_ON | level, 3, 0);
+  RADIOLIB_ASSERT(state);
+
+  // set DIO mapping
+  switch(pin) {
+    case(0):
+      return(this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO0_PACK_TEMP_CHANGE_LOW_BAT, 7, 6));
+    case(3):
+      return(this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_1, RADIOLIB_SX127X_DIO3_CONT_TEMP_CHANGE_LOW_BAT, 1, 0));
+    case(4):
+      return(this->mod->SPIsetRegValue(RADIOLIB_SX127X_REG_DIO_MAPPING_2, RADIOLIB_SX127X_DIO4_PACK_TEMP_CHANGE_LOW_BAT, 7, 6));
+  }
+  return(RADIOLIB_ERR_INVALID_DIO_PIN);
+}
+
 #endif
diff --git a/src/modules/SX127x/SX127x.h b/src/modules/SX127x/SX127x.h
index bf09b925c..fd3d4a94a 100644
--- a/src/modules/SX127x/SX127x.h
+++ b/src/modules/SX127x/SX127x.h
@@ -472,14 +472,14 @@
 // RADIOLIB_SX127X_REG_LOW_BAT
 #define RADIOLIB_SX127X_LOW_BAT_OFF                             0b00000000  //  3     3   low battery detector disabled
 #define RADIOLIB_SX127X_LOW_BAT_ON                              0b00001000  //  3     3   low battery detector enabled
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_1_695_V                    0b00000000  //  2     0   battery voltage threshold: 1.695 V
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_1_764_V                    0b00000001  //  2     0                              1.764 V
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_1_835_V                    0b00000010  //  2     0                              1.835 V (default)
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_1_905_V                    0b00000011  //  2     0                              1.905 V
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_1_976_V                    0b00000100  //  2     0                              1.976 V
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_2_045_V                    0b00000101  //  2     0                              2.045 V
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_2_116_V                    0b00000110  //  2     0                              2.116 V
-#define RADIOLIB_SX127X_LOW_BAT_TRIM_2_185_V                    0b00000111  //  2     0                              2.185 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_1_695_V               0b00000000  //  2     0   battery voltage threshold: 1.695 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_1_764_V               0b00000001  //  2     0                              1.764 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_1_835_V               0b00000010  //  2     0                              1.835 V (default)
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_1_905_V               0b00000011  //  2     0                              1.905 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_1_976_V               0b00000100  //  2     0                              1.976 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_2_045_V               0b00000101  //  2     0                              2.045 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_2_116_V               0b00000110  //  2     0                              2.116 V
+#define RADIOLIB_SX127X_LOW_BAT_THRESHOLD_2_185_V               0b00000111  //  2     0                              2.185 V
 
 // RADIOLIB_SX127X_REG_IRQ_FLAGS_1
 #define RADIOLIB_SX127X_FLAG_MODE_READY                         0b10000000  //  7     7   requested mode is ready
@@ -1216,6 +1216,16 @@ class SX127x: public PhysicalLayer {
     */
     int16_t setRSSIThreshold(float dbm);
 
+    /*!
+      \brief Set low battery indicator threshold.
+      \param level Battery threshold level (one of RADIOLIB_SX127X_LOW_BAT_THRESHOLD_*),
+      or -1 to disable the detector. Disabled by default. Note that this will not attach any interrupts!
+      \param pin DIO pin number which will be used to signal low battery. Only DIO0/4 can be used
+      (in packet mode) or DIO3/4 (in continuous mode). Ignored when disabling the detector.
+      \returns \ref status_codes
+    */
+    int16_t setLowBatteryThreshold(int8_t level, uint32_t pin = RADIOLIB_NC);
+
 #if !RADIOLIB_GODMODE && !RADIOLIB_LOW_LEVEL
   protected:
 #endif