From 7e42f77c95d6b5c6f36b7c555ae4d66091c48d61 Mon Sep 17 00:00:00 2001
From: Federico Maggi <federico.maggi@gmail.com>
Date: Wed, 6 Nov 2019 02:34:40 +0100
Subject: [PATCH] Added length mode configuration methods and handling

---
 src/modules/CC1101.cpp | 57 +++++++++++++++++++++++++++++++++++-------
 src/modules/CC1101.h   | 19 ++++++++++++++
 2 files changed, 67 insertions(+), 9 deletions(-)

diff --git a/src/modules/CC1101.cpp b/src/modules/CC1101.cpp
index 42fe5d7f..905fcac9 100644
--- a/src/modules/CC1101.cpp
+++ b/src/modules/CC1101.cpp
@@ -3,6 +3,7 @@
 CC1101::CC1101(Module* module) : PhysicalLayer(CC1101_CRYSTAL_FREQ, CC1101_DIV_EXPONENT, CC1101_MAX_PACKET_LENGTH) {
   _mod = module;
   _packetLengthQueried = false;
+  _packetLengthConfig = CC1101_LENGTH_CONFIG_VARIABLE;
 }
 
 int16_t CC1101::begin(float freq, float br, float rxBw, float freqDev, int8_t power) {
@@ -20,15 +21,15 @@ int16_t CC1101::begin(float freq, float br, float rxBw, float freqDev, int8_t po
       flagFound = true;
     } else {
       #ifdef RADIOLIB_DEBUG
-        Serial.print(F("CC1101 not found! ("));
-        Serial.print(i + 1);
-        Serial.print(F(" of 10 tries) CC1101_REG_VERSION == "));
+        RADIOLIB_DEBUG_PRINT(F("CC1101 not found! ("));
+        RADIOLIB_DEBUG_PRINT(i + 1);
+        RADIOLIB_DEBUG_PRINT(F(" of 10 tries) CC1101_REG_VERSION == "));
 
         char buffHex[7];
         sprintf(buffHex, "0x%04X", version);
-        Serial.print(buffHex);
-        Serial.print(F(", expected 0x0014"));
-        Serial.println();
+        RADIOLIB_DEBUG_PRINT(buffHex);
+        RADIOLIB_DEBUG_PRINT(F(", expected 0x0014"));
+        RADIOLIB_DEBUG_PRINTLN();
       #endif
       delay(1000);
       i++;
@@ -192,8 +193,10 @@ int16_t CC1101::startTransmit(uint8_t* data, size_t len, uint8_t addr) {
     return(state);
   }
 
-  // write packet length
-  SPIwriteRegister(CC1101_REG_FIFO, len);
+  // optionally write packet length
+  if (_packetLengthConfig == CC1101_LENGTH_CONFIG_VARIABLE) {
+    SPIwriteRegister(CC1101_REG_FIFO, len);
+  }
 
   // check address filtering
   uint8_t filter = SPIgetRegValue(CC1101_REG_PKTCTRL1, 1, 0);
@@ -477,7 +480,11 @@ uint8_t CC1101::getLQI() {
 
 size_t CC1101::getPacketLength(bool update) {
   if(!_packetLengthQueried && update) {
-    _packetLength = _mod->SPIreadRegister(CC1101_REG_FIFO);
+
+    uint8_t format = SPIgetRegValue(CC1101_REG_PKTCTRL0, 1, 0);
+    if (format == CC1101_LENGTH_CONFIG_VARIABLE) {
+      _packetLength = _mod->SPIreadRegister(CC1101_REG_FIFO);
+    } 
     _packetLengthQueried = true;
   }
 
@@ -497,6 +504,38 @@ int16_t CC1101::config() {
   return(state);
 }
 
+int16_t CC1101::fixedPacketLengthMode(uint8_t len) {
+  if (len > CC1101_MAX_PACKET_LENGTH) {
+    return(ERR_PACKET_TOO_LONG);
+  }
+
+  uint16_t state = SPIsetRegValue(CC1101_REG_PKTCTRL0, CC1101_LENGTH_CONFIG_FIXED, 1, 0);
+  if (state != ERR_NONE) {
+    return(state);
+  }
+
+  state = SPIsetRegValue(CC1101_REG_PKTLEN, len);
+  if (state != ERR_NONE) {
+    return(state);
+  }
+}
+
+int16_t CC1101::variablePacketLengthMode(uint8_t maxLen) {
+  if (maxLen > CC1101_MAX_PACKET_LENGTH) {
+    return(ERR_PACKET_TOO_LONG);
+  }
+
+  uint16_t state = SPIsetRegValue(CC1101_REG_PKTCTRL0, CC1101_LENGTH_CONFIG_VARIABLE, 1, 0);
+  if (state != ERR_NONE) {
+    return(state);
+  }
+
+  state = SPIsetRegValue(CC1101_REG_PKTLEN, maxLen);
+  if (state != ERR_NONE) {
+    return(state);
+  }
+}
+
 int16_t CC1101::directMode() {
   // set mode to standby
   SPIsendCommand(CC1101_CMD_IDLE);
diff --git a/src/modules/CC1101.h b/src/modules/CC1101.h
index a2060819..c57a7e6d 100644
--- a/src/modules/CC1101.h
+++ b/src/modules/CC1101.h
@@ -739,6 +739,24 @@ class CC1101: public PhysicalLayer {
     */
     size_t getPacketLength(bool update = true);
 
+     /*!
+      \brief Set modem in fixed packet length mode.
+
+      \param len Packet length.
+
+      \returns \ref status_codes
+    */
+    int16_t fixedPacketLengthMode(uint8_t len = CC1101_MAX_PACKET_LENGTH);
+
+     /*!
+      \brief Set modem in variable packet length mode.
+
+      \param len Maximum packet length.
+
+      \returns \ref status_codes
+    */
+    int16_t variablePacketLengthMode(uint8_t maxLen = CC1101_MAX_PACKET_LENGTH);
+
   private:
     Module* _mod;
 
@@ -748,6 +766,7 @@ class CC1101: public PhysicalLayer {
 
     size_t _packetLength;
     bool _packetLengthQueried;
+    uint8_t _packetLengthConfig;
 
     int16_t config();
     int16_t directMode();