Merge pull request #354 from Beaky2000/float-print-bug

floats >= 100 cause the CLI to hang

src/main/common/typeconversion.c

@@ -144,6 +144,11 @@ char *itoa(int i, char *a, int base)
 
 #endif
 
+/* Note: the floatString must be at least 13 bytes long to cover all cases.
+ * This includes up to 10 digits (32 bit ints can hold numbers up to 10
+ * digits long) + the decimal point + negative sign or space + null
+ * terminator.
+ */
 char *ftoa(float x, char *floatString)
 {
     int32_t value;

src/main/common/typeconversion.h

@@ -21,7 +21,17 @@ void li2a(long num, char *bf);
 void ui2a(unsigned int num, unsigned int base, int uc, char *bf);
 void i2a(int num, char *bf);
 char a2i(char ch, const char **src, int base, int *nump);
+
+/* Simple conversion of a float to a string. Will display completely
+ * inaccurate results for floats larger than about 2.15E6 (2^31 / 1000)
+ * (same thing for negative values < -2.15E6).
+ * Will always display 3 decimals, so anything smaller than 1E-3 will
+ * not be displayed.
+ * The floatString will be filled in with the result and will be
+ * returned. It must be at least 13 bytes in length to cover all cases!
+ */
 char *ftoa(float x, char *floatString);
+
 float fastA2F(const char *p);
 
 #ifndef HAVE_ITOA_FUNCTION

src/main/io/serial_cli.c

@@ -2446,7 +2446,7 @@ static void cliWrite(uint8_t ch)
 static void cliPrintVar(const clivalue_t *var, uint32_t full)
 {
     int32_t value = 0;
-    char buf[8];
+    char buf[13];
 
     void *ptr = var->ptr;
     if ((var->type & VALUE_SECTION_MASK) == PROFILE_VALUE) {