Added function to test a single address

Author: bitbank2

README.txt

@@ -40,6 +40,8 @@ unsigned char ucMap[16];
 
 I2CScan(ucMap);
 
+To detect if a single address is active, use I2CTest(addr).
+
 For reading and writing data to the I2C device, use the following functions:
 
 I2CRead(uint8_t u8Address, uint8_t *pu8Data, int iLength);

library.properties

@@ -1,5 +1,5 @@
 name=BitBang_I2C
-version=1.0.0
+version=1.1.0
 author=Larry Bank <[email protected]>
 maintainer=Larry Bank <[email protected]>
 sentence=Bit-bang the I2C protocol on any 2 GPIO pins on any system.

src/BitBang_I2C.cpp

@@ -493,6 +493,21 @@ void I2CInit(int iSDA_Pin, int iSCL_Pin, int32_t iClock)
    else iDelay = 1000000 / iClock;
 } /* i2cInit() */
 //
+// Test a specific I2C address to see if a device responds
+// returns 0 for no response, 1 for a response
+//
+uint8_t I2CTest(uint8_t addr)
+{
+uint8_t response = 0;
+
+  if (i2cBegin(addr, 0)) // try to write to the given address
+  {
+    response = 1;
+  }
+  i2cEnd();
+  return response;
+} /* I2CTest() */
+//
 // Scans for I2C devices on the bus
 // returns a bitmap of devices which are present (128 bits = 16 bytes, LSB first)
 // A set bit indicates that a device responded at that address

src/BitBang_I2C.h

@@ -36,6 +36,12 @@ int I2CWrite(uint8_t iAddr, uint8_t *pData, int iLen);
 //
 // Scans for I2C devices on the bus
 // returns a bitmap of devices which are present (128 bits = 16 bytes, LSB first)
+//
+// Test if an address responds
+// returns 0 if no response, 1 if it responds
+//
+uint8_t I2CTest(uint8_t addr);
+
 // A set bit indicates that a device responded at that address
 //
 void I2CScan(uint8_t *pMap);