From 37a0c56bfec870944194b48dc20dfc15eec5f3d8 Mon Sep 17 00:00:00 2001
From: Libor Tomsik <libor@tomsik.eu>
Date: Thu, 15 Apr 2021 12:50:49 +0200
Subject: [PATCH] Added method for reading current AFC value

---
 src/modules/SX127x/SX127x.cpp | 16 ++++++++++++++++
 src/modules/SX127x/SX127x.h   |  7 +++++++
 2 files changed, 23 insertions(+)

diff --git a/src/modules/SX127x/SX127x.cpp b/src/modules/SX127x/SX127x.cpp
index 917560ad..9d2e00ee 100644
--- a/src/modules/SX127x/SX127x.cpp
+++ b/src/modules/SX127x/SX127x.cpp
@@ -669,6 +669,22 @@ float SX127x::getFrequencyError(bool autoCorrect) {
   return(ERR_UNKNOWN);
 }
 
+float SX127x::getAFCError()
+{
+  // check active modem
+  int16_t modem = getActiveModem();
+  if(modem != SX127X_FSK_OOK) {
+    return 0;
+  }
+
+  // get raw frequency error
+  int16_t raw = (uint16_t)_mod->SPIgetRegValue(SX127X_REG_AFC_MSB) << 8;
+  raw |= _mod->SPIgetRegValue(SX127X_REG_AFC_LSB);
+
+  uint32_t base = 1;
+  return raw * (32000000.0 / (float)(base << 19));
+}
+
 float SX127x::getSNR() {
   // check active modem
   if(getActiveModem() != SX127X_LORA) {
diff --git a/src/modules/SX127x/SX127x.h b/src/modules/SX127x/SX127x.h
index b5621b22..66c5442b 100644
--- a/src/modules/SX127x/SX127x.h
+++ b/src/modules/SX127x/SX127x.h
@@ -773,6 +773,13 @@ class SX127x: public PhysicalLayer {
     */
     float getFrequencyError(bool autoCorrect = false);
 
+    /*!
+      \brief Gets current AFC error.
+
+      \returns Frequency offset from RF in Hz if AFC is enabled and triggered, zero otherwise.
+    */
+    float getAFCError();
+
     /*!
       \brief Gets signal-to-noise ratio of the latest received packet.