Add hwFreeMem() function

libraries/MySensors/core/MyHwATMega328.cpp

@@ -152,7 +152,7 @@ uint16_t hwCPUVoltage() {
 	return (1125300UL) / ADC;
 }
 
-uint8_t hwCPUFrequency() {
+uint16_t hwCPUFrequency() {
 	noInterrupts();
 	// setup timer1
 	TIFR1 = 0xFF;   
@@ -180,6 +180,12 @@ uint8_t hwCPUFrequency() {
 	return TCNT1 * 2048UL / 100000UL;
 }
 
+uint16_t hwFreeMem() {
+	extern int __heap_start, *__brkval; 
+	int v; 
+	return (int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval); 
+}
+
 
 
 #ifdef MY_DEBUG

libraries/MySensors/core/MyHwESP8266.cpp

@@ -126,6 +126,10 @@ uint16_t hwCPUFrequency() {
 	return ESP.getCpuFreqMHz()*10;
 }
 
+uint16_t hwFreeMem() {
+	return ESP.getFreeHeap();
+}
+
 #ifdef MY_DEBUG
 void hwDebugPrint(const char *fmt, ... ) {
 	char fmtBuffer[300];

libraries/MySensors/core/MyHwSAMD.cpp

@@ -138,6 +138,21 @@ int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mo
   return -2;
 }
 
+uint16_t hwCPUVoltage() {
+	// TODO: Not supported!
+	return 0;
+}
+ 
+uint16_t hwCPUFrequency() {
+	// TODO: Not supported!
+	return 0;
+}
+ 
+uint16_t hwFreeMem() {
+	// TODO: Not supported!
+	return 0;
+}
+
 #ifdef MY_DEBUG
 void hwDebugPrint(const char *fmt, ... ) {
   if (MY_SERIALDEVICE) {