I2C hang recover function added

Dependencies:   UniGraphic mbed vt100

In this version, check_i2c_pins function was added in edge_mgr.cpp.

プログラムの起動時、I2Cモジュールを初期化する前に、I2Cに使用するピンの電位を確認し
もし一方でも Low に張り付いていた場合、SCL を GPIO 出力に設定して 
所定回数 (I2C_UNLOCK_TRIAL_CYCLE) 反転させることにより、疑似リセットクロックを生成します。

その後は、通常の起動手順に復帰し、以降はこれまでと同様の動作をします。

Revision:
0:d895cd1cd897
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/afLib/iafLib.h	Tue Apr 03 08:30:29 2018 +0000
@@ -0,0 +1,126 @@
+/**
+ * Copyright 2015 Afero, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * afLib public interface
+ *
+ * This file defines everything your application should need for commuinicating with the Afero ASR-1 radio module.
+ * Is there is anything missing from this file, please post a request on the developer forum and we will see what
+ * we can do.
+ */
+#ifndef AFLIB_IAFLIB_H
+#define AFLIB_IAFLIB_H
+
+#include "mbed.h"
+#include <string>
+using namespace std;
+#include "afErrors.h"
+#include "afSPI.h"
+
+#if defined (TARGET_TEENSY3_1)
+    #include "USBSerial.h"
+#endif
+
+#define afMINIMUM_TIME_BETWEEN_REQUESTS     1000
+
+#define MAX_ATTRIBUTE_SIZE                  255
+
+typedef void (*isr)();
+typedef void (*onAttributeSet)(const uint8_t requestId, const uint16_t attributeId, const uint16_t valueLen, const uint8_t *value);
+typedef void (*onAttributeSetComplete)(const uint8_t requestId, const uint16_t attributeId, const uint16_t valueLen, const uint8_t *value);
+
+class iafLib {
+public:
+    /**
+     * create
+     *
+     * Create an instance of the afLib object. The afLib is a singleton. Calling this method multiple
+     * times will return the same instance.
+     *
+     * @param   mcuInterrupt    The Arduino interrupt to be used (returned from digitalPinToInterrupt)
+     * @param   isrWrapper      This is the isr method that must be defined in your sketch
+     * @param   attrSet         Callback for notification of attribute set requests
+     * @param   attrSetComplete Callback for notification of attribute set request completions
+     * @return  iafLib *        Instance of iafLib
+     */
+    static iafLib * create(PinName mcuInterrupt, isr isrWrapper,
+        onAttributeSet attrSet, onAttributeSetComplete attrSetComplete, afSPI *theSPI);
+                           
+    //wsugi 20161128
+    static void destroy();
+
+    /**
+     * loop
+     *
+     * Called by the loop() method in your sketch to give afLib some CPU time
+     */
+    virtual void loop(void) = 0;
+
+    /**
+     * getAttribute
+     *
+     * Request the value of an attribute be returned from the ASR-1.
+     * Value will be returned in the attrSetComplete callback.
+     */
+    virtual int getAttribute(const uint16_t attrId) = 0;
+
+    /**
+     * setAttribute
+     *
+     * Request setting an attribute.
+     * For MCU attributes, the attribute value will be updated.
+     * For IO attributes, the attribute value will be updated, and then onAttrSetComplete will be called.
+     */
+    virtual int setAttributeBool(const uint16_t attrId, const bool value) = 0;
+
+    virtual int setAttribute8(const uint16_t attrId, const int8_t value) = 0;
+
+    virtual int setAttribute16(const uint16_t attrId, const int16_t value) = 0;
+
+    virtual int setAttribute32(const uint16_t attrId, const int32_t value) = 0;
+
+    virtual int setAttribute64(const uint16_t attrId, const int64_t value) = 0;
+
+    virtual int setAttribute(const uint16_t attrId, const string &value) = 0;
+
+    virtual int setAttribute(const uint16_t attrId, const uint16_t valueLen, const char *value) = 0;
+
+    virtual int setAttribute(const uint16_t attrId, const uint16_t valueLen, const uint8_t *value) = 0;
+
+    /**
+     * setAttributeComplete
+     *
+     * Call this in response to an onAttrSet. This lets the ASR-1 know that the set request has been handled.
+     */
+    virtual int setAttributeComplete(uint8_t requestId, const uint16_t attrId, const uint16_t valueLen, const uint8_t *value) = 0;
+
+    /**
+     * isIdle
+     *
+     * Call to find out of the ASR-1 is currently handling a request.
+     *
+     * @return true if an operation is in progress
+     */
+    virtual bool isIdle() = 0;
+
+    /**
+     * mcuISR
+     *
+     * Called by your sketch to pass the interrupt along to afLib.
+     */
+    virtual void mcuISR() = 0;
+};
+#endif //AFLIB_IAFLIB_H
\ No newline at end of file