added readme.md, updated examples

libraries/PrintSize/examples/PrintSize1/PrintSize1.ino

@@ -6,6 +6,7 @@
 //
 // HISTORY:
 // 0.1.0   2017-12-09 initial version
+// 0.1.1   2020-02-19 refactored, simpler printSpaces()
 //
 
 #include "PrintSize.h"
@@ -20,8 +21,12 @@ void setup()
   Serial.println("Determine length of 10 random numbers and right ");
   Serial.println("align the numbers in a table with their sum.");
   Serial.println();
+}
 
+void loop()
+{
   uint32_t sum = 0;
+
   for (int i = 0; i < 10; i++)
   {
     uint32_t rn = random(100000000);
@@ -30,24 +35,16 @@ void setup()
     sum += rn;
     Serial.println(rn);
   }
+
   Serial.print("================ +\n");
   int length = ps.println(sum);
   printSpaces(15 - length);
   Serial.println(sum);
+  Serial.println();
 }
 
-void loop()
+void printSpaces(uint8_t n)
 {
-
-}
-
-void printSpaces(int n)
-{
-  if (n <= 0) return;
-  while (n)
-  {
-    Serial.print(' ');
-    n--;
-  }
+  while (n--) Serial.print(' ');
 }
 

libraries/PrintSize/examples/PrintSize_printf/PrintSize_printf.ino

@@ -0,0 +1,54 @@
+//
+//    FILE: PrintSize_printf.ino
+//  AUTHOR: Rob Tillaart
+// VERSION: 0.1.0
+// PURPOSE: demo printSize printf
+//
+//    NOTE:
+// - UNO does not support printf, - ESP32 does
+//
+// HISTORY:
+// 0.1.0   2020-02-16 initial version
+//
+
+#include "PrintSize.h"
+
+PrintSize ps;
+
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(__FILE__);
+
+  Serial.println("Determine length of 10 random numbers and right ");
+  Serial.println("align the numbers in a table with their sum.");
+  Serial.println();
+}
+
+
+void loop()
+{
+  uint32_t sum = 0;
+
+  for (int i = 0; i < 10; i++)
+  {
+    uint32_t rn = random(100000000);
+    int length = ps.printf("%u\n", rn);
+    printSpaces(15 - length);
+    sum += rn;
+    Serial.printf("%u\n", rn);
+  }
+
+  Serial.print("================ +\n");
+  int length = ps.printf("%u\n", sum);
+  printSpaces(15 - length);
+  Serial.printf("%u\n\n", sum);
+  delay(1000);
+}
+
+
+void printSpaces(uint8_t n)
+{
+  while (n--) Serial.print(' ');
+}

libraries/PrintSize/readme.md

@@ -0,0 +1,18 @@
+
+# PrintSize
+
+PrintSize is a minimal library to determine the length of a variable when printed.
+This includes printing of floats
+
+## Examples
+Example show the alignment of 10 random numbers, 
+both print(), println() and if supported printf().
+
+
+### notes
+Can be used to calculate the needed space.
+ - to properly do a right alignment e.g. for numbers. 
+ - do left alignement and overwrite previous output with spaces.
+ - centering of numbers
+ - see if output will fit into a line.
+