From fd6fa2fe44a39a8d7b83bed1fe24ee7427c0a863 Mon Sep 17 00:00:00 2001
From: Starbeamrainbowlabs <sbrl@starbeamrainbowlabs.com>
Date: Sat, 22 Jul 2017 15:10:38 +0100
Subject: [PATCH] Add I2C device scanner

---
 I2cScanner/I2cScanner.ino | 81 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 I2cScanner/I2cScanner.ino

diff --git a/I2cScanner/I2cScanner.ino b/I2cScanner/I2cScanner.ino
new file mode 100644
index 0000000..34f9b83
--- /dev/null
+++ b/I2cScanner/I2cScanner.ino
@@ -0,0 +1,81 @@
+/* --------------------------------------
+ * i2c_scanner
+ * 
+ * Version 1
+ * 	This program (or code that looks like it)
+ * 	can be found in many places.
+ * 	For example on the Arduino.cc forum.
+ * 	The original author is not know.
+ * Version 2, Juni 2012, Using Arduino 1.0.1
+ *	Adapted to be as simple as possible by Arduino.cc user Krodal
+ * Version 3, Feb 26  2013
+ * 	V3 by louarnold
+ * Version 4, March 3, 2013, Using Arduino 1.0.3
+ * 	by Arduino.cc user Krodal.
+ * 	Changes by louarnold removed.
+ * 	Scanning addresses changed from 0...127 to 1...119,
+ * 	according to the i2c scanner by Nick Gammon
+ * 
+ * Version 5, March 28, 2013
+ * 	As version 4, but address scans now to 127.
+ * 	A sensor seems to use address 120.
+ * Version 6, November 27, 2015.
+ * 	Added waiting for the Leonardo serial communication.
+ * This sketch tests the standard 7-bit addresses
+ * Devices with higher bit address might not be seen properly.
+ */
+
+#include <Wire.h>
+
+
+void setup()
+{
+	Wire.begin();
+	
+	Serial.begin(9600);
+	while (!Serial);             // Leonardo: wait for serial monitor
+	Serial.println("\nI2C Scanner");
+}
+
+
+void loop()
+{
+	byte error, address;
+	int nDevices;
+	
+	Serial.println("Scanning...");
+	
+	nDevices = 0;
+	for(address = 1; address < 127; address++ )
+	{
+		// The i2c_scanner uses the return value of
+		// the Write.endTransmisstion to see if
+		// a device did acknowledge to the address.
+		Wire.beginTransmission(address);
+		error = Wire.endTransmission();
+		
+		if (error == 0)
+		{
+			Serial.print("I2C device found at address 0x");
+			if (address<16)
+				Serial.print("0");
+			Serial.print(address,HEX);
+			Serial.println("  !");
+			
+			nDevices++;
+		}
+		else if (error==4)
+		{
+			Serial.print("Unknown error at address 0x");
+			if (address<16)
+				Serial.print("0");
+			Serial.println(address,HEX);
+		}
+	}
+	if (nDevices == 0)
+	Serial.println("No I2C devices found\n");
+	else
+	Serial.println("done\n");
+	
+	delay(5000);           // wait 5 seconds for next scan
+}