From abbefd122671f9d531e1da1a90954cae27f66a55 Mon Sep 17 00:00:00 2001
From: jgromes <jgromes@users.noreply.github.com>
Date: Sat, 13 Feb 2021 17:41:41 +0100
Subject: [PATCH] [RF69] Added -1 as alias for lowest supported frequency
 deviation

---
 src/modules/RF69/RF69.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/modules/RF69/RF69.cpp b/src/modules/RF69/RF69.cpp
index c5350fc8..65aa67b1 100644
--- a/src/modules/RF69/RF69.cpp
+++ b/src/modules/RF69/RF69.cpp
@@ -505,8 +505,14 @@ int16_t RF69::setRxBandwidth(float rxBw) {
 }
 
 int16_t RF69::setFrequencyDeviation(float freqDev) {
+  // set frequency deviation to lowest available setting (required for digimodes)
+  float newFreqDev = freqDev;
+  if(freqDev < 0.0) {
+    newFreqDev = 0.6;
+  }
+
   // check frequency deviation range
-  if(!((freqDev + _br/2 <= 500))) {
+  if(!((newFreqDev + _br/2 <= 500))) {
     return(ERR_INVALID_FREQUENCY_DEVIATION);
   }
 
@@ -515,7 +521,7 @@ int16_t RF69::setFrequencyDeviation(float freqDev) {
 
   // set frequency deviation from carrier frequency
   uint32_t base = 1;
-  uint32_t fdev = (freqDev * (base << 19)) / 32000;
+  uint32_t fdev = (newFreqDev * (base << 19)) / 32000;
   int16_t state = _mod->SPIsetRegValue(RF69_REG_FDEV_MSB, (fdev & 0xFF00) >> 8, 5, 0);
   state |= _mod->SPIsetRegValue(RF69_REG_FDEV_LSB, fdev & 0x00FF, 7, 0);