Fixes #1 adding support for 16MHz. Found bug with missing output3ByteUDouble

Author: ieb

SmallNMEA2000.cpp

@@ -7,11 +7,11 @@
 
 
 
-bool SNMEA2000::open() {
+bool SNMEA2000::open(byte clockSet) {
     if ( canIsOpen ) {
         return true;
     }
-    uint8_t res =  CAN.begin(CAN_250KBPS, MCP_8MHz);
+    uint8_t res =  CAN.begin(CAN_250KBPS, clockSet);
     if (res == CAN_OK ) {
         canIsOpen = true;
         delay(200);
@@ -329,6 +329,21 @@ void SNMEA2000::output3ByteDouble(double value, double precision) {
         outputByte((i>>16)&0xff);
     }
 }
+void SNMEA2000::output3ByteUDouble(double value, double precision) {
+    if (value == SNMEA2000::n2kDoubleNA ) {
+        // undef is 2147483647 = FFFFFF
+        outputByte(0xff);
+        outputByte(0xff);
+        outputByte(0xff);
+    } else {
+        double vd=value/precision;
+        vd = round(vd);
+        int32_t i = (vd>=0 && vd<16777214L)?(int32_t)vd:16777214L;
+        outputByte(i&0xff);
+        outputByte((i>>8)&0xff);
+        outputByte((i>>16)&0xff);
+    }
+}
 
 void SNMEA2000::output4ByteDouble(double value, double precision) {
     if (value == SNMEA2000::n2kDoubleNA ) {
@@ -340,7 +355,7 @@ void SNMEA2000::output4ByteDouble(double value, double precision) {
     } else {
         double vd=value/precision;
         vd = round(vd);
-        int32_t i = (vd>=-2147483648L && vd<0x7ffffffe)?(int32_t)vd:0x7ffffffe;
+        int32_t i = (vd>=-2147483648L && vd<2147483647L)?(int32_t)vd:2147483647L;
         outputByte(i&0xff);
         outputByte((i>>8)&0xff);
         outputByte((i>>16)&0xff);

SmallNMEA2000.h

@@ -262,7 +262,7 @@ class SNMEA2000 {
         {
         };
 
-        bool open();
+        bool open(byte clockSet = MCP_8MHz);
         void processMessages();
         void dumpStatus() {
             console->print(F("NMEA2000 Status open="));
@@ -305,6 +305,7 @@ class SNMEA2000 {
         void output2ByteDouble(double v, double p);
         void output2ByteUDouble(double v, double p);
         void output3ByteDouble(double v, double p);
+        void output3ByteUDouble(double v, double p);
         void output4ByteDouble(double v, double p);
         void output4ByteUDouble(double v, double p);
 
@@ -319,8 +320,6 @@ class SNMEA2000 {
         static constexpr double n2kDoubleNA=-1000000000.0;
         static const uint8_t n2kInt8NA=127;
 
-    protected:
-        Print * console;
 
     private:
         void handleISOAddressClaim(MessageHeader *messageHeader, byte * buffer, int len);
@@ -382,6 +381,9 @@ class SNMEA2000 {
         uint16_t packetErrors = 0;
         uint16_t frameErrors = 0;
 
+    protected:
+        Print * console;
+
 
 
 };