basic led code

lib/sprocket-utils/utils_print.cpp

@@ -0,0 +1,25 @@
+#include "utils_print.h"
+
+int FORMAT_BUFFER_SIZE(const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    int result = vsnprintf(NULL, 0, format, args);
+    va_end(args);
+    return result + 1; // safe byte for \0
+}
+void PRINT_MSG(Print &out, const char* prefix, const char* format, ...) {
+    if(SPROCKET_PRINT){
+        out.print(String(prefix) + String(": "));
+        char formatString[128], *ptr;
+        strncpy_P( formatString, format, sizeof(formatString) ); // copy in from program mem
+        // null terminate - leave last char since we might need it in worst case for result's \0
+        formatString[ sizeof(formatString)-2 ]='\0'; 
+        ptr=&formatString[ strlen(formatString)+1 ]; // our result buffer...
+        va_list args;
+        va_start (args,format);
+        vsnprintf(ptr, sizeof(formatString)-1-strlen(formatString), formatString, args );
+        va_end (args);
+        formatString[ sizeof(formatString)-1 ]='\0'; 
+        out.print(ptr);
+    }
+}

lib/sprocket-utils/utils_print.h

@@ -0,0 +1,15 @@
+#ifndef __SPROCKET_UTILS__
+#define __SPROCKET_UTILS__
+
+#include <Arduino.h>
+
+#ifndef SPROCKET_PRINT
+#define SPROCKET_PRINT 1
+#endif
+
+// TODO move to sprocket
+
+int FORMAT_BUFFER_SIZE(const char* format, ...);
+void PRINT_MSG(Print &out, const char* prefix, const char* format, ...);
+
+#endif