From e3075c02e27851e7c15aac5c567b81ef4db1d9c0 Mon Sep 17 00:00:00 2001
From: "rjbatista@gmail.com"
 <rjbatista@gmail.com@f0354187-03e1-8ba3-851e-26a5c8714c44>
Date: Wed, 19 Oct 2011 23:43:58 +0000
Subject: [PATCH] added support for removing leading zeros in displaying
 numbers

---
 CHANGES.txt | 15 +++++++++++++++
 TM1638.cpp  | 23 ++++++++++++++++++-----
 TM1638.h    | 11 ++++++-----
 3 files changed, 39 insertions(+), 10 deletions(-)
 create mode 100644 CHANGES.txt

diff --git a/CHANGES.txt b/CHANGES.txt
new file mode 100644
index 0000000..8a23e95
--- /dev/null
+++ b/CHANGES.txt
@@ -0,0 +1,15 @@
+Version 1.3.0
+
+- added support for removing leading zeros in displaying numbers.
+
+Version 1.2.0
+
+- added support for writing text.
+
+Version 1.1.0
+
+- restructuring and added 2 proper examples, available in the arduino ide.
+
+Version 1.0.0
+
+- initial Release.
diff --git a/TM1638.cpp b/TM1638.cpp
index cc17237..6f16280 100644
--- a/TM1638.cpp
+++ b/TM1638.cpp
@@ -51,15 +51,19 @@ void TM1638::setupDisplay(boolean active, byte intensity)
 }
 
 
-void TM1638::setDisplayToHexNumber(unsigned long number, byte dots)
+void TM1638::setDisplayToHexNumber(unsigned long number, byte dots, boolean leadingZeros)
 {
   for (int i = 0; i < 8; i++) {
-    setDisplayDigit(number & 0xF, 7 - i, (dots & (1 << i)) != 0);
-    number >>= 4;
+	if (!leadingZeros && number == 0) {
+		clearDisplayDigit(7 - i, (dots & (1 << i)) != 0);
+	} else {
+		setDisplayDigit(number & 0xF, 7 - i, (dots & (1 << i)) != 0);
+		number >>= 4;
+    }
   }
 }
 
-void TM1638::setDisplayToDecNumber(unsigned long number, byte dots)
+void TM1638::setDisplayToDecNumber(unsigned long number, byte dots, boolean leadingZeros)
 {
   if (number > 99999999L) {
     setDisplay(ERROR);
@@ -69,7 +73,11 @@ void TM1638::setDisplayToDecNumber(unsigned long number, byte dots)
         setDisplayDigit(number % 10, 7 - i, (dots & (1 << i)) != 0);
         number /= 10;
       } else {
-        setDisplayDigit(0, 7 - i, (dots & (1 << i)) != 0);
+	    if (leadingZeros) {
+			setDisplayDigit(0, 7 - i, (dots & (1 << i)) != 0);
+		} else {
+			clearDisplayDigit(7 - i, (dots & (1 << i)) != 0);
+		}
       }
     }
   }
@@ -87,6 +95,11 @@ void TM1638::setDisplayDigit(byte digit, byte pos, boolean dot)
   sendData(pos << 1, NUMBER_DATA[digit & 0xF] | (dot ? 0b10000000 : 0));
 }
 
+void TM1638::clearDisplayDigit(byte pos, boolean dot)
+{
+  sendData(pos << 1, (dot ? 0b10000000 : 0));
+}
+
 void TM1638::setDisplay(const byte values[])
 {
   for (int i = 0; i < 8; i++) {
diff --git a/TM1638.h b/TM1638.h
index a187cc4..9c1e596 100644
--- a/TM1638.h
+++ b/TM1638.h
@@ -36,14 +36,16 @@ class TM1638
     /** Set the display (segments and LEDs) active or off and intensity (range from 0-7). */
     void setupDisplay(boolean active, byte intensity);
 
-    /** Set the display to a unsigned hexadecimal number */
-    void setDisplayToHexNumber(unsigned long number, byte dots);
-    /** Set the display to a unsigned decimal number */
-    void setDisplayToDecNumber(unsigned long number, byte dots);
+    /** Set the display to a unsigned hexadecimal number (with or without leading zeros) */
+    void setDisplayToHexNumber(unsigned long number, byte dots, boolean leadingZeros = true);
+    /** Set the display to a unsigned decimal number (with or without leading zeros) */
+    void setDisplayToDecNumber(unsigned long number, byte dots, boolean leadingZeros = true);
     /** Set the display to a unsigned binary number */
     void setDisplayToBinNumber(byte number, byte dots);
     /** Set a single display at pos (starting at 0) to a digit (left to right) */ 
     void setDisplayDigit(byte digit, byte pos, boolean dot);
+    /** Clear  a single display at pos (starting at 0, left to right) */ 
+    void clearDisplayDigit(byte pos, boolean dot);
     /** Set the display to the 8 values (left to right) */
     void setDisplay(const byte values[]);
     /** Clear the display */
@@ -72,4 +74,3 @@ class TM1638
 };
 
 #endif
-