Prevent I2C lockups

libraries/Wire/src/Wire.cpp

@@ -18,6 +18,7 @@
 
   Modified 2012 by Todd Krein ([email protected]) to implement repeated starts
   Modified 2017 by Chuck Todd ([email protected]) to correct Unconfigured Slave Mode reboot
+  Modified 2018 by Frank Paynter ([email protected]) to prevent while() loop deadlocks
 */
 
 extern "C" {
@@ -52,6 +53,16 @@ TwoWire::TwoWire()
 
 // Public Methods //////////////////////////////////////////////////////////////
 
+//08/09/18 gfp: added for lockup monitoring
+void TwoWire::clearRecoveryCount()
+{
+	twi_clearRecoveryCount();
+}
+uint16_t TwoWire::getRecoveryCount()
+{
+	return twi_getRecoveryCount();
+}
+
 void TwoWire::begin(void)
 {
   rxBufferIndex = 0;

libraries/Wire/src/Wire.h

@@ -1,22 +1,22 @@
 /*
-  TwoWire.h - TWI/I2C library for Arduino & Wiring
-  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
+TwoWire.h - TWI/I2C library for Arduino & Wiring
+Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
 
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
+This library is free software; you can redistribute it and/or
+modify it under the terms of the GNU Lesser General Public
+License as published by the Free Software Foundation; either
+version 2.1 of the License, or (at your option) any later version.
 
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+Lesser General Public License for more details.
 
-  You should have received a copy of the GNU Lesser General Public
-  License along with this library; if not, write to the Free Software
-  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+You should have received a copy of the GNU Lesser General Public
+License along with this library; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
-  Modified 2012 by Todd Krein ([email protected]) to implement repeated starts
+Modified 2012 by Todd Krein ([email protected]) to implement repeated starts
 */
 
 #ifndef TwoWire_h
@@ -32,51 +32,55 @@
 
 class TwoWire : public Stream
 {
-  private:
-    static uint8_t rxBuffer[];
-    static uint8_t rxBufferIndex;
-    static uint8_t rxBufferLength;
-
-    static uint8_t txAddress;
-    static uint8_t txBuffer[];
-    static uint8_t txBufferIndex;
-    static uint8_t txBufferLength;
-
-    static uint8_t transmitting;
-    static void (*user_onRequest)(void);
-    static void (*user_onReceive)(int);
-    static void onRequestService(void);
-    static void onReceiveService(uint8_t*, int);
-  public:
-    TwoWire();
-    void begin();
-    void begin(uint8_t);
-    void begin(int);
-    void end();
-    void setClock(uint32_t);
-    void beginTransmission(uint8_t);
-    void beginTransmission(int);
-    uint8_t endTransmission(void);
-    uint8_t endTransmission(uint8_t);
-    uint8_t requestFrom(uint8_t, uint8_t);
-    uint8_t requestFrom(uint8_t, uint8_t, uint8_t);
+private:
+	static uint8_t rxBuffer[];
+	static uint8_t rxBufferIndex;
+	static uint8_t rxBufferLength;
+
+	static uint8_t txAddress;
+	static uint8_t txBuffer[];
+	static uint8_t txBufferIndex;
+	static uint8_t txBufferLength;
+
+	static uint8_t transmitting;
+	static void(*user_onRequest)(void);
+	static void(*user_onReceive)(int);
+	static void onRequestService(void);
+	static void onReceiveService(uint8_t*, int);
+public:
+	TwoWire();
+	void begin();
+	void begin(uint8_t);
+	void begin(int);
+	void end();
+	void setClock(uint32_t);
+	void beginTransmission(uint8_t);
+	void beginTransmission(int);
+	uint8_t endTransmission(void);
+	uint8_t endTransmission(uint8_t);
+	uint8_t requestFrom(uint8_t, uint8_t);
+	uint8_t requestFrom(uint8_t, uint8_t, uint8_t);
 	uint8_t requestFrom(uint8_t, uint8_t, uint32_t, uint8_t, uint8_t);
-    uint8_t requestFrom(int, int);
-    uint8_t requestFrom(int, int, int);
-    virtual size_t write(uint8_t);
-    virtual size_t write(const uint8_t *, size_t);
-    virtual int available(void);
-    virtual int read(void);
-    virtual int peek(void);
-    virtual void flush(void);
-    void onReceive( void (*)(int) );
-    void onRequest( void (*)(void) );
-
-    inline size_t write(unsigned long n) { return write((uint8_t)n); }
-    inline size_t write(long n) { return write((uint8_t)n); }
-    inline size_t write(unsigned int n) { return write((uint8_t)n); }
-    inline size_t write(int n) { return write((uint8_t)n); }
-    using Print::write;
+	uint8_t requestFrom(int, int);
+	uint8_t requestFrom(int, int, int);
+	virtual size_t write(uint8_t);
+	virtual size_t write(const uint8_t *, size_t);
+	virtual int available(void);
+	virtual int read(void);
+	virtual int peek(void);
+	virtual void flush(void);
+	void onReceive(void(*)(int));
+	void onRequest(void(*)(void));
+
+	//08/09/18 gfp: added for lockup monitoring
+	void clearRecoveryCount();
+	uint16_t getRecoveryCount();
+
+	inline size_t write(unsigned long n) { return write((uint8_t)n); }
+	inline size_t write(long n) { return write((uint8_t)n); }
+	inline size_t write(unsigned int n) { return write((uint8_t)n); }
+	inline size_t write(int n) { return write((uint8_t)n); }
+	using Print::write;
 };
 
 extern TwoWire Wire;