Implemented LoRa promiscuous mode

Config.h

@@ -4,7 +4,7 @@
 	#define CONFIG_H
 
 	#define MAJ_VERS  0x01
-	#define MIN_VERS  0x04
+	#define MIN_VERS  0x05
 
 	#define MCU_328P  0x90
 	#define MCU_1284P 0x91
@@ -77,6 +77,8 @@
 	bool radio_locked = true;
 	bool radio_online = false;
 	bool hw_ready     = false;
+	bool promisc      = false;
+
 	uint8_t op_mode   = MODE_HOST;
 	uint8_t model     = 0x00;
 	uint8_t hwrev     = 0x00;

RNode_Firmware.ino

@@ -89,6 +89,12 @@ void update_radio_lock() {
 }
 
 void receiveCallback(int packet_size) {
+  if (!promisc) {
+    // The standard operating mode allows large
+    // packets with a payload up to 500 bytes,
+    // by combining two raw LoRa packets.
+    // We read the 1-byte header and extract
+    // packet sequence number and split flags
     uint8_t header   = LoRa.read(); packet_size--;
     uint8_t sequence = packetSequence(header);
     bool    ready    = false;
@@ -142,6 +148,31 @@ void receiveCallback(int packet_size) {
       Serial.write(CMD_STAT_RSSI);
       Serial.write((uint8_t)(last_rssi-rssi_offset));
 
+      // And then write the entire packet
+      Serial.write(FEND);
+      Serial.write(CMD_DATA);
+      for (int i = 0; i < read_len; i++) {
+        uint8_t byte = pbuf[i];
+        if (byte == FEND) { Serial.write(FESC); byte = TFEND; }
+        if (byte == FESC) { Serial.write(FESC); byte = TFESC; }
+        Serial.write(byte);
+      }
+      Serial.write(FEND);
+      read_len = 0;
+    }  
+  } else {
+    // In promiscuous mode, raw packets are
+    // output directly over to the host
+    read_len = 0;
+    last_rssi = LoRa.packetRssi();
+    getPacketData(packet_size);
+
+    // We first signal the RSSI of the
+    // recieved packet to the host.
+    Serial.write(FEND);
+    Serial.write(CMD_STAT_RSSI);
+    Serial.write((uint8_t)(last_rssi-rssi_offset));
+
     // And then write the entire packet
     Serial.write(FEND);
     Serial.write(CMD_DATA);
@@ -216,6 +247,7 @@ void processQueue() {
 
 void transmit(size_t size) {
   if (radio_online) {
+    if (!promisc) {
       led_tx_on();
       size_t  written = 0;
       uint8_t header  = random(256) & 0xF0;
@@ -248,7 +280,33 @@ void transmit(size_t size) {
       led_tx_off();
 
       LoRa.receive();
+    } else {
+      // In promiscuous mode, we only send out
+      // plain raw LoRa packets with a maximum
+      // payload of 255 bytes
+      led_tx_on();
+      size_t  written = 0;
       
+      // Cap packets at 255 bytes
+      if (size > SINGLE_MTU) {
+        size = SINGLE_MTU;
+      }
+
+      LoRa.beginPacket();
+      for (size_t i; i < size; i++) {
+        #if QUEUE_SIZE > 0
+          LoRa.write(tbuf[i]);
+        #else
+          LoRa.write(sbuf[i]);
+        #endif
+
+        written++;
+      }
+      LoRa.endPacket();
+      led_tx_off();
+
+      LoRa.receive();
+    }
   } else {
     kiss_indicate_error(ERROR_TXFAILED);
     led_indicate_error(5);
@@ -400,6 +458,13 @@ void serialCallback(uint8_t sbyte) {
       if (sbyte == DETECT_REQ) {
         kiss_indicate_detect();
       }
+    } else if (command == CMD_PROMISC) {
+      if (sbyte == 0x01) {
+        promisc_enable();
+      } else if (sbyte == 0x00) {
+        promisc_disable();
+      }
+      kiss_indicate_promisc();
     } else if (command == CMD_UNLOCK_ROM) {
       if (sbyte == ROM_UNLOCK_BYTE) {
         unlock_rom();

Utilities.cpp

@@ -199,6 +199,17 @@ void kiss_indicate_ready() {
 	Serial.write(FEND);
 }
 
+void kiss_indicate_promisc() {
+	Serial.write(FEND);
+	Serial.write(CMD_PROMISC);
+	if (promisc) {
+		Serial.write(0x01);
+	} else {
+		Serial.write(0x00);
+	}
+	Serial.write(FEND);
+}
+
 void kiss_indicate_detect() {
 	Serial.write(FEND);
 	Serial.write(CMD_DETECT);
@@ -278,6 +289,14 @@ uint8_t getRandom() {
 	}
 }
 
+void promisc_enable() {
+	promisc = true;
+}
+
+void promisc_disable() {
+	promisc = false;
+}
+
 bool eeprom_info_locked() {
 	uint8_t lock_byte = EEPROM.read(eeprom_addr(ADDR_INFO_LOCK));
 	if (lock_byte == INFO_LOCK_BYTE) {