UNTESTED join change, TESTED: downlink buffer overflow protection and…

… an example with downlink.

README.md

@@ -45,8 +45,9 @@ The majority of the work was done by Hendrik Hagendorn and Ideetron B.V. Thanks
 - [x] ADR_ACK_LIMIT
 - [x] NbTrans
 - [x] Channel Mask
+- [x] RxTimingSetup
 
-# MAC commands added but untested
+## MAC commands added but untested
 
 - [ ] Added battery Level to DevStatusAns. Battery status is working, I think margin is wrong.
 
@@ -73,18 +74,18 @@ Solutions with avr style.
 
 # TODO's (PR's welcome) - In order of importance.
 
-- [ ] CFlist
 - [ ] Join back-off
 - [ ] Confirmed Uplink
 - [ ] Confirmed Downlink
+- [ ] Extern variable for Duty Cycle if the application can provide time.
 - [ ] Make DevNonce random.
 - [ ] More regions. Currently only EU868 is working.
 - [ ] Add pin mappings infrastucture for other boards.
 - [ ] Add compile options for battery status (unable to measure, connected to external power)
-- [ ] Respect Dwell MAC command (only for US902?)
 - [ ] Random delay for TX.
 - [ ] Duty Cycle per channel.
-- [ ] extern variable for Duty Cycle if the application can provide time.
+- [ ] Respect Dwell MAC command (only for US902?)
+- [ ] CFlist only for US and AS?
 
 # Undoable on AVR and Deep Sleep
 

SlimLoRa.cpp

@@ -1334,8 +1334,9 @@ void SlimLoRa::ProcessFrameOptions(uint8_t *options, uint8_t f_options_length) {
 				// Apply ChMask
 				// TODO US: Apply ChMask according to ChMaskCntl. p. 33 Regional parameters
 				if ( new_rx2_dr == 0 ) { 
-					// BUG? Always zero?
 					ChMask = (uint16_t) options[i + 2] | options[i + 3] << 8;
+
+					// Store to EEPROM
 					SetChMask();
 
 					#if DEBUG_SLIM == 1
@@ -1507,6 +1508,8 @@ void SlimLoRa::ProcessFrameOptions(uint8_t *options, uint8_t f_options_length) {
 				new_rx2_dr = (options[i + 1] & 0xF);
 				// zero value = 1
 				if ( new_rx2_dr == 0 ) { new_rx2_dr = 1; }
+
+				// Save to EEPROM
 				SetRx1Delay(new_rx2_dr);
 				rx1_delay_micros_ = GetRx1Delay() * MICROS_PER_SECOND;
 
@@ -1547,6 +1550,10 @@ void SlimLoRa::ProcessFrameOptions(uint8_t *options, uint8_t f_options_length) {
  * @return 0 if successful, else error code.
  */
 int8_t SlimLoRa::ProcessDownlink(uint8_t window) {
+	// start fresh
+	downlinkSize = 0;
+	downPort = 0;
+
 	int8_t result;
 	uint8_t rx1_offset_dr;
 	uint8_t temp;
@@ -1663,18 +1670,6 @@ int8_t SlimLoRa::ProcessDownlink(uint8_t window) {
 	#endif
 
 	}
-	//
-	// This does not goes well with my procedure to read downlink application data.
-	// EEPROM corruption, hung and restart.
-       /*	else {
-	#if DEBUG_SLIM == 1
-		Serial.print(F("\nMAC else downPort: "));Serial.println(downPort);Serial.flush();
-	#endif
-		// Process MAC commands
-		f_options_length = packet[5] & 0xF;
-		ProcessFrameOptions(&packet[8], f_options_length);
-	}
-	*/
 
 	// application downlink
 	if ( downPort > 0 && downPort < 224 ) { // downPort 0 and 224 are special case
@@ -1697,7 +1692,6 @@ int8_t SlimLoRa::ProcessDownlink(uint8_t window) {
 
 		// stollen from MAC command
 		payload_length = packet_length - LORAWAN_MAC_AND_FRAME_HEADER - f_options_length - LORAWAN_MIC_SIZE;
-		//payload_length = packet_length - 8 - f_options_length - 4;
 		#if DEBUG_SLIM == 1
 			Serial.print(F("\nPacket RAW HEX"));printHex(packet, packet_length);
 			printDownlink();
@@ -1707,14 +1701,29 @@ int8_t SlimLoRa::ProcessDownlink(uint8_t window) {
 		EncryptPayload(&packet[LORAWAN_MAC_AND_FRAME_HEADER + f_options_length + LORAWAN_PORT_SIZE], payload_length, frame_counter, LORAWAN_DIRECTION_DOWN);
 
 		// Store downlink payload to downlinkData. Skip MAC header and Device Address.
-		// Data starts at 10th byte and ends 4 bytes - before MIC;
-		downlinkSize = 0;
-		for ( temp = LORAWAN_START_OF_FRM_PAYLOAD - 1; temp < packet_length - LORAWAN_MIC_SIZE; temp++) {
+		temp = LORAWAN_START_OF_FRM_PAYLOAD;				// Data starts at 10th byte and ends 4 bytes before MIC
+		for ( ; downlinkSize < payload_length - 1; downlinkSize++) {	// BUG? payload_length is always plus 1. WHY?
+
+			if ( downlinkSize > DOWNLINK_PAYLOAD_SIZE ) {		// Protection for buffer overflow.
+										// If downlinkSize > DOWNLINK_PAYLOAD_SIZE invalidate and abort income data.
+
+				#if DEBUG_SLIM == 1
+				Serial.print(F("\ndownlinkSize is larger than DOWNLINK_PAYLOAD_SIZE: "));Serial.print(DOWNLINK_PAYLOAD_SIZE);
+				Serial.print(F("\ndownlinkSize: "));Serial.print(downlinkSize);
+				#endif
+
+				downlinkSize = 0;
+
+				break;
+			}
 			downlinkData[downlinkSize] = packet[temp];
-			downlinkSize++;
+			temp++;
 		}
+
 		#if DEBUG_SLIM == 1
+		if ( downlinkSize > 0 ) {
 			Serial.print(F("\nDownlinkData"));printHex(downlinkData, downlinkSize);
+		}
 		#endif
 	}
 
@@ -2449,7 +2458,7 @@ uint16_t SlimLoRa::GetTxFrameCounter() {
 void SlimLoRa::SetTxFrameCounter(uint16_t count) {
 	eeprom_write_word(&eeprom_lw_tx_frame_counter, count);
 #if DEBUG_SLIM == 1
-	Serial.print(F("\nWRITE Tx#: "));Serial.print(count >> 8);Serial.print(count);
+	Serial.print(F("\nWRITE Tx#: "));Serial.print(count);
 #endif
 }
 
@@ -2491,20 +2500,10 @@ uint8_t SlimLoRa::GetRx2DataRate() {
 
 	if (value == 0xFF) {
 #if LORAWAN_OTAA_ENABLED
-		return SF12BW125;
-	#if NETWORK == 'NET_TTN' // TTN
+		// return SF12BW125;
 		return RX_SECOND_WINDOW;
-	#endif // TTN
-	#if NETWORK == 'NET_HELIUM' // Helium
-		return RX_SECOND_WINDOW;
-	#endif // HELIUM
 #else
-	#if NETWORK == 'NET_TTN' // TTN
-		return RX_SECOND_WINDOW;
-	#endif // TTN
-	#if NETWORK == 'NET_TTN' // TTN
 		return RX_SECOND_WINDOW;
-	#endif // Helium
 #endif // LORAWAN_OTAA_ENABLED
 	}
 	return value;
@@ -2580,7 +2579,7 @@ void SlimLoRa::SetTxFrameCounter(uint16_t count) {
 	//EEPROM.update(EEPROM_TX_COUNTER, count);
 	EEPROM.put(EEPROM_TX_COUNTER, count);
 #if DEBUG_SLIM == 1
-	Serial.print(F("\nWRITE Tx#: "));Serial.print(count >> 8);Serial.print(count);
+	Serial.print(F("\nWRITE Tx#: "));Serial.print(count);
 #endif
 }
 

SlimLoRa.h

@@ -17,7 +17,7 @@
 #define NBTRANS	1
 
 // TTN or Helium
-#define NETWORK 'NET_HELIUM'	// Two options: NET_HLM = helium, NET_TTN = TheThingsNetwork
+#define NETWORK 'NET_TTN'	// Two options: NET_HLM = helium, NET_TTN = TheThingsNetwork
 				// NET_TTN: RX2 SF9
 				// NET_HLM: RX2 SF12
 
@@ -28,12 +28,12 @@
 // I think helium needs re-join. EVAL with chripstack
 
 // I propose to you that you config your device on the console.helium.com to 5 seconds RX DELAY.
-// By Default HELIUM uses 1 sec of delay
-#define NET_HELIUM_RX_DELAY	5
-
 // Make sure this value is the same with TTN console.
 #define NET_TTN_RX_DELAY	5
 
+// By Default HELIUM uses 1 sec of delay, but join is always at 5 seconds
+#define NET_HELIUM_RX_DELAY	5
+
 // Select Arduino style EEPROM handling.
 #define ARDUINO_EEPROM	1	// Uses static storage, but it helps debugging.
 
@@ -49,6 +49,9 @@
 #define EEPROM_WRITE_TX_COUNT	200	// SlimLoRa default: 10
 #define EEPROM_WRITE_RX_COUNT	10	// SlimLoRa default: 3
 
+// downlink size payload. You can gain some flash / RAM memory here
+#define DOWNLINK_PAYLOAD_SIZE	12	// more than 51 bytes is impossible in SF12
+
 // LoRaWAN ADR
 // https://lora-developers.semtech.com/documentation/tech-papers-and-guides/implementing-adaptive-data-rate-adr/implementing-adaptive-data-rate/
 #define LORAWAN_ADR_ACK_LIMIT   164	// Request downlink after XX uplinks to verify we have connection.	Minimum sane value: 64
@@ -161,7 +164,8 @@
 #define LORAWAN_DIRECTION_UP                0
 #define LORAWAN_DIRECTION_DOWN              1
 
-#define LORAWAN_UPLINK_CHANNEL_COUNT        8 // Valid Values 8 or 16. Used for ChMask
+#define LORAWAN_UPLINK_CHANNEL_COUNT        8 // Valid Value only 8. 
+					      // In future downlink channel must move to another index - not 8 or in another variable.
 
 // LoRaWAN frame options
 #define LORAWAN_FOPT_LINK_CHECK_REQ         0x02
@@ -199,7 +203,7 @@
 #define LORAWAN_PORT_SIZE			1
 #define LORAWAN_MIC_SIZE			4
 #define LORAWAN_MAC_AND_FRAME_HEADER		8 // MAC Header is 1 byte. Frame header is 7..22 bytes
-#define LORAWAN_START_OF_FRM_PAYLOAD		10
+#define LORAWAN_START_OF_FRM_PAYLOAD		9
 
 // LoRaWAN Join packet sizes
 #define LORAWAN_JOIN_REQUEST_SIZE           18
@@ -308,7 +312,7 @@ class SlimLoRa {
     void setArrayEEPROM(uint16_t eepromAdr, uint8_t *arrayData, uint8_t size);
 #endif
 
-	uint8_t downlinkData[12]; // hardcoded to 12 bytes
+	uint8_t downlinkData[DOWNLINK_PAYLOAD_SIZE];
 	uint8_t downlinkSize;
 	uint8_t downPort;
 

examples/SlimLoRa-feather32u4-battery-complicated/01_config.ino

@@ -1,6 +1,6 @@
 #define HLM // TTN or HLM (helium) MSB values
 
-// JS DECODER for Helium or TTN
+// JS DECODER for TTN or Helium.
 /*
 
 function Decoder(bytes, port) {

examples/SlimLoRa-feather32u4-battery-complicated/02_functions.ino

@@ -4,7 +4,7 @@
 #endif
 
 void checkBatt(){
-    vbat = analogRead(VBATPIN) - 450; // convert to 8bit
+    vbat = analogRead(VBATPIN) - 450; // fit to 8bit. Will add 450 on decoder.
     /*
     vbat *= 2;    // we divided by 2, so multiply back
     vbat *= 3.3;  // Multiply by 3.3V, our reference voltage
@@ -74,27 +74,4 @@ void blinkLed(uint16_t times, uint16_t duration, uint8_t pause) { // x, ms, seco
         Serial.println();
 }
 
-void printMAC_EEPROM(){
-      Serial.println(F("MAC STATE from EEPROM"));
-      #if LORAWAN_OTAA_ENABLED // You define this on SlimLoRa.h file.
-                                          Serial.print(F("EEPROM join: "));Serial.println(lora.GetHasJoined());
-      #else
-                                          Serial.print(F("ABP DevAddr"));printHexB(DevAddr, 4);
-      #endif // LORAWAN_OTAA_ENABLED
-      lora.GetDevAddr(temp)              ;Serial.print(F("DevAdd"));printHexB(temp, 4);
-                                          Serial.print(F("Tx_#       : "));Serial.println(lora.GetTxFrameCounter()); // Serial.print(F("\tRAM: "));Serial.println(tx_frame_counter_);
-                                          Serial.print(F("Rx_#       : "));Serial.println(lora.GetRxFrameCounter()); // Serial.print(F("\tRAM: "));Serial.println(rx_frame_counter_);
-                                          Serial.print(F("Rx1 delay  : "));Serial.print(lora.GetRx1Delay());Serial.print(F(", System Setting: "));Serial.print(LORAWAN_JOIN_ACCEPT_DELAY1_MICROS / 1000000);Serial.print("s, RX2: ");Serial.print(LORAWAN_JOIN_ACCEPT_DELAY2_MICROS / 1000000);Serial.println("s, ");
-                                          Serial.print(F("Rx1 DR Offset: "));Serial.println(lora.GetRx1DataRateOffset());
-                                          Serial.print(F("DevNonce   : "));Serial.print(lora.GetDevNonce() >> 8);Serial.println(lora.GetDevNonce());
-                                          Serial.print(F("JoinNonce  : "));Serial.print(lora.GetJoinNonce() >> 24);Serial.print(lora.GetJoinNonce() >> 16);Serial.print(lora.GetJoinNonce() >> 8);Serial.println(lora.GetJoinNonce());
-      // Don't publish those values!
-      #if KEYS_EXPORT == 1
-      lora.GetAppSKey(temp)              ;Serial.print(F("AppSKey     NOWEB"))    ;printHexB(temp, 16);
-      lora.GetFNwkSIntKey(temp)          ;Serial.print(F("FNwkSIntKey NOWEB"));printHexB(temp, 16);
-      lora.GetSNwkSIntKey(temp)          ;Serial.print(F("SNwkSIntKey NOWEB"));printHexB(temp, 16);
-      lora.GetNwkSEncKey(temp)           ;Serial.print(F("NwkSEncKey  NOWEB")) ;printHexB(temp, 16);
-      #endif
-}
-
 #endif // DEBUG_INO