Force LDO option set or unset (sandeepmistry#668)

* Force LDO option set or unset

Some remote clients needs LDO using on any Spreading Factor. CDEbyte E32 for example.

* LDO state setter function realized

* Update keywords, minor style tweaks

---------

Co-authored-by: Sandeep Mistry <[email protected]>

Author: zbx-sadman

keywords.txt

@@ -51,6 +51,8 @@ enableCrc	KEYWORD2
 disableCrc	KEYWORD2
 enableInvertIQ	KEYWORD2
 disableInvertIQ	KEYWORD2
+enableLowDataRateOptimize	KEYWORD2
+disableLowDataRateOptimize	KEYWORD2
 setGain	KEYWORD2
 
 random	KEYWORD2

src/LoRa.cpp

@@ -586,6 +586,13 @@ void LoRaClass::setLdoFlag()
   writeRegister(REG_MODEM_CONFIG_3, config3);
 }
 
+void LoRaClass::setLdoFlagForced(const boolean ldoOn)
+{
+  uint8_t config3 = readRegister(REG_MODEM_CONFIG_3);
+  bitWrite(config3, 3, ldoOn);
+  writeRegister(REG_MODEM_CONFIG_3, config3);
+}
+
 void LoRaClass::setCodingRate4(int denominator)
 {
   if (denominator < 5) {
@@ -632,6 +639,16 @@ void LoRaClass::disableInvertIQ()
   writeRegister(REG_INVERTIQ2, 0x1d);
 }
 
+void LoRaClass::enableLowDataRateOptimize()
+{
+   setLdoFlagForced(true);
+}
+
+void LoRaClass::disableLowDataRateOptimize()
+{
+   setLdoFlagForced(false);
+}
+
 void LoRaClass::setOCP(uint8_t mA)
 {
   uint8_t ocpTrim = 27;

src/LoRa.h

@@ -79,6 +79,8 @@ class LoRaClass : public Stream {
   void disableCrc();
   void enableInvertIQ();
   void disableInvertIQ();
+  void enableLowDataRateOptimize();
+  void disableLowDataRateOptimize();
 
   void setOCP(uint8_t mA); // Over Current Protection control
 
@@ -107,6 +109,7 @@ class LoRaClass : public Stream {
   long getSignalBandwidth();
 
   void setLdoFlag();
+  void setLdoFlagForced(const boolean);
 
   uint8_t readRegister(uint8_t address);
   void writeRegister(uint8_t address, uint8_t value);