Various bugfixes

LibAPRS/AFSK.cpp

@@ -1,5 +1,6 @@
 #include <string.h>
 #include "AFSK.h"
+#include "Arduino.h"
 
 extern unsigned long custom_preamble;
 extern unsigned long custom_tail;
@@ -465,7 +466,7 @@ ISR(ADC_vect) {
     }
 
     poll_timer++;
-    if (poll_timer > 4) {
+    if (poll_timer > 3) {
         poll_timer = 0;
         APRS_poll();
     }

LibAPRS/LibAPRS.cpp

@@ -58,7 +58,6 @@ void APRS_poll(void) {
 }
 
 void APRS_setCallsign(char *call, int ssid) {
-    Serial.println("Setting to: ");
     memset(CALL, 0, 7);
     int i = 0;
     while (i < 6 && call[i] != 0) {
@@ -171,23 +170,22 @@ void APRS_setDirectivity(int s) {
 }
 
 void APRS_printSettings() {
-    Serial.println("LibAPRS Settings:");
-    Serial.print("Callsign:     "); Serial.print(CALL); Serial.print("-"); Serial.println(CALL_SSID);
-    Serial.print("Destination:  "); Serial.print(DST); Serial.print("-"); Serial.println(DST_SSID);
-    Serial.print("Path1:        "); Serial.print(PATH1); Serial.print("-"); Serial.println(PATH1_SSID);
-    Serial.print("Path2:        "); Serial.print(PATH2); Serial.print("-"); Serial.println(PATH2_SSID);
-    Serial.print("Message dst:  "); if (message_recip[0] == 0) { Serial.println("N/A"); } else { Serial.print(message_recip); Serial.print("-"); Serial.println(message_recip_ssid); }
-    Serial.print("TX Preamble:  "); Serial.println(custom_preamble);
-    Serial.print("TX Tail:      "); Serial.println(custom_tail);
-    Serial.print("Symbol table: "); if (symbolTable = '/') { Serial.println("Normal"); } else { Serial.println("Alternate"); }
-    Serial.print("Symbol:       "); Serial.println(symbol);
-    Serial.print("Power:        "); if (power < 10) { Serial.println(power); } else { Serial.println("N/A"); }
-    Serial.print("Height:       "); if (height < 10) { Serial.println(height); } else { Serial.println("N/A"); }
-    Serial.print("Gain:         "); if (gain < 10) { Serial.println(gain); } else { Serial.println("N/A"); }
-    Serial.print("Directivity:  "); if (directivity < 10) { Serial.println(directivity); } else { Serial.println("N/A"); }
-    Serial.print("Latitude:     "); if (latitude[0] != 0) { Serial.println(latitude); } else { Serial.println("N/A"); }
-    Serial.print("Longtitude:   "); if (longtitude[0] != 0) { Serial.println(longtitude); } else { Serial.println("N/A"); }
-
+    Serial.println(F("LibAPRS Settings:"));
+    Serial.print(F("Callsign:     ")); Serial.print(CALL); Serial.print(F("-")); Serial.println(CALL_SSID);
+    Serial.print(F("Destination:  ")); Serial.print(DST); Serial.print(F("-")); Serial.println(DST_SSID);
+    Serial.print(F("Path1:        ")); Serial.print(PATH1); Serial.print(F("-")); Serial.println(PATH1_SSID);
+    Serial.print(F("Path2:        ")); Serial.print(PATH2); Serial.print(F("-")); Serial.println(PATH2_SSID);
+    Serial.print(F("Message dst:  ")); if (message_recip[0] == 0) { Serial.println(F("N/A")); } else { Serial.print(message_recip); Serial.print(F("-")); Serial.println(message_recip_ssid); }
+    Serial.print(F("TX Preamble:  ")); Serial.println(custom_preamble);
+    Serial.print(F("TX Tail:      ")); Serial.println(custom_tail);
+    Serial.print(F("Symbol table: ")); if (symbolTable = '/') { Serial.println(F("Normal")); } else { Serial.println(F("Alternate")); }
+    Serial.print(F("Symbol:       ")); Serial.println(symbol);
+    Serial.print(F("Power:        ")); if (power < 10) { Serial.println(power); } else { Serial.println(F("N/A")); }
+    Serial.print(F("Height:       ")); if (height < 10) { Serial.println(height); } else { Serial.println(F("N/A")); }
+    Serial.print(F("Gain:         ")); if (gain < 10) { Serial.println(gain); } else { Serial.println(F("N/A")); }
+    Serial.print(F("Directivity:  ")); if (directivity < 10) { Serial.println(directivity); } else { Serial.println(F("N/A")); }
+    Serial.print(F("Latitude:     ")); if (latitude[0] != 0) { Serial.println(latitude); } else { Serial.println(F("N/A")); }
+    Serial.print(F("Longtitude:   ")); if (longtitude[0] != 0) { Serial.println(longtitude); } else { Serial.println(F("N/A")); }
 }
 
 void APRS_sendPkt(void *_buffer, size_t length) {
@@ -214,6 +212,7 @@ void APRS_sendPkt(void *_buffer, size_t length) {
     ax25_sendVia(&AX25, path, countof(path), buffer, length);
 }
 
+// Dynamic RAM usage of this function is 30 bytes
 void APRS_sendLoc(void *_buffer, size_t length) {
     size_t payloadLength = 20+length;
     bool usePHG = false;
@@ -250,6 +249,7 @@ void APRS_sendLoc(void *_buffer, size_t length) {
     free(packet);
 }
 
+// Dynamic RAM usage of this function is 18 bytes
 void APRS_sendMsg(void *_buffer, size_t length) {
     if (length > 67) length = 67;
     size_t payloadLength = 11+length+4;
@@ -299,11 +299,44 @@ void APRS_sendMsg(void *_buffer, size_t length) {
     packet[14+length] = n+48;
     
     APRS_sendPkt(packet, payloadLength);
-
     free(packet);
 }
 
 void APRS_msgRetry() {
     message_seq--;
     APRS_sendMsg(lastMessage, lastMessageLen);
+}
+
+// For getting free memory, from:
+// http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1213583720/15
+
+extern unsigned int __heap_start;
+extern void *__brkval;
+
+struct __freelist {
+  size_t sz;
+  struct __freelist *nx;
+};
+
+extern struct __freelist *__flp;
+
+int freeListSize() {
+  struct __freelist* current;
+  int total = 0;
+  for (current = __flp; current; current = current->nx) {
+    total += 2; /* Add two bytes for the memory block's header  */
+    total += (int) current->sz;
+  }
+  return total;
+}
+
+int freeMemory() {
+  int free_memory;
+  if ((int)__brkval == 0) {
+    free_memory = ((int)&free_memory) - ((int)&__heap_start);
+  } else {
+    free_memory = ((int)&free_memory) - ((int)__brkval);
+    free_memory += freeListSize();
+  }
+  return free_memory;
 }

LibAPRS/LibAPRS.h

@@ -34,4 +34,6 @@ void APRS_sendLoc(void *_buffer, size_t length);
 void APRS_sendMsg(void *_buffer, size_t length);
 void APRS_msgRetry();
 
-void APRS_printSettings();
+void APRS_printSettings();
+
+int freeMemory();

LibAPRS/examples/Basic_usage/Basic_usage.ino

@@ -18,15 +18,46 @@
 // You always need to include this function. It will
 // get called by the library every time a packet is
 // received, so you can process incoming packets.
+// 
+// IMPORTANT! This function is called from within an
+// interrupt. That means that you should only do things
+// here that are FAST. Don't print out info directly
+// from this function, instead set a flag and print it
+// from your main loop, like this:
+
+boolean gotPacket = false;
+AX25Msg incomingPacket;
+uint8_t *packetData;
 void aprs_msg_callback(struct AX25Msg *msg) {
-  Serial.print("Received APRS packet. Data: ");
-  for (int i = 0; i < msg->len; i++) { Serial.write(msg->info[i]); }
-  Serial.println("");
+  // If we already have a packet waiting to be
+  // processed, we must drop the new one.
+  if (!gotPacket) {
+    // Set flag to indicate we got a packet
+    gotPacket = true;
+
+    // The memory referenced as *msg is volatile
+    // and we need to copy all the data to a
+    // local variable for later processing.
+    memcpy(&incomingPacket, msg, sizeof(AX25Msg));
+
+    // We need to allocate a new buffer for the
+    // data payload of the packet. First we check
+    // if there is enough free RAM.
+    if (freeMemory() > msg->len) {
+      packetData = (uint8_t*)malloc(msg->len);
+      memcpy(packetData, msg->info, msg->len);
+      incomingPacket.info = packetData;
+    } else {
+      // We did not have enough free RAM to receive
+      // this packet, so we drop it.
+      gotPacket = false;
+    }
+  }
 }
 
 void setup() {
   // Set up serial port
-  Serial.begin(9600);
+  Serial.begin(115200);
   
   // Initialise APRS library - This starts the modem
   APRS_init();
@@ -36,25 +67,26 @@ void setup() {
   
   // You don't need to set the destination identifier, but
   // if you want to, this is how you do it:
-  APRS_setDestination("APZMDM", 0);
+  // APRS_setDestination("APZMDM", 0);
   
   // Path parameters are set to sensible values by
   // default, but this is how you can configure them:
-  APRS_setPath1("WIDE1", 1);
-  APRS_setPath2("WIDE2", 2);
+  // APRS_setPath1("WIDE1", 1);
+  // APRS_setPath2("WIDE2", 2);
   
   // You can define preamble and tail like this:
-  APRS_setPreamble(350);
-  APRS_setTail(50);
+  // APRS_setPreamble(350);
+  // APRS_setTail(50);
   
   // You can use the normal or alternate symbol table:
-  APRS_useAlternateSymbolTable(false);
+  // APRS_useAlternateSymbolTable(false);
   
   // And set what symbol you want to use:
-  APRS_setSymbol('n');
+  // APRS_setSymbol('n');
   
   // We can print out all the settings
   APRS_printSettings();
+  Serial.print(F("Free RAM:     ")); Serial.println(freeMemory());
 }
 
 void locationUpdateExample() {
@@ -79,7 +111,7 @@ void locationUpdateExample() {
   char *comment = "LibAPRS location update";
     
   // And send the update
-  APRS_sendLoc(comment, sizeof(comment));
+  APRS_sendLoc(comment, strlen(comment));
   
 }
 
@@ -88,19 +120,44 @@ void messageExample() {
   APRS_setMessageDestination("AA3BBB", 0);
   
   // And define a string to send
-  char *message = "Hi there! This is a message";
-  APRS_sendMsg(message, sizeof(message));
+  char *message = "Hi there! This is a message.";
+  APRS_sendMsg(message, strlen(message));
   
 }
 
+// Here's a function to process incoming packets
+// Remember to call this function often, so you
+// won't miss any packets due to one already
+// waiting to be processed
+void processPacket() {
+  if (gotPacket) {
+    gotPacket = false;
+    Serial.print(F("Received APRS packet. Data: "));
+    for (int i = 0; i < incomingPacket.len; i++) {
+      Serial.write(incomingPacket.info[i]);
+    }
+    Serial.println("");
+
+    // Remeber to free memory for our buffer!
+    free(packetData);
+
+    // You can print out the amount of free
+    // RAM to check you don't have any memory
+    // leaks
+    // Serial.print(F("Free RAM: ")); Serial.println(freeMemory());
+  }
+}
+
+boolean whichExample = false;
 void loop() {
   delay(2000);
-  locationUpdateExample();
-  
-  delay(2000);
-  messageExample();
 
-  // Just for fun we print out the settings
-  APRS_printSettings();
+  processPacket();
+  if (whichExample) {
+    locationUpdateExample();
+  } else {
+    messageExample();
+  }
+  whichExample ^= true;
 
 }

README.md

@@ -17,4 +17,8 @@ See the example included in the library for info on how to use it!
 - Ability to send raw packets
 - Support for settings APRS symbols
 - Support for power/height/gain info in location updates
-- Can run with open squelch
+- Can run with open squelch
+
+## Installation
+
+Place the "LibAPRS" folder (the one in the same folder as this readme file) inside your Arduino "libraries" folder. That's all!