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/edge_sensor/edge_accel.cpp	Tue Apr 03 08:30:29 2018 +0000
@@ -0,0 +1,163 @@
+#include "mbed.h"
+#include "afLib.h"
+#include "edge_reset_mgr.h"
+#include "edge_sensor.h"
+#include "edge_accel.h"
+#include "MMA8451Q.h"
+
+edge_accel::edge_accel(MMA8451Q *accel) : edge_sensor() 
+{
+    _accel = accel ;
+    _sample_count = 0 ;
+    _accumulation = 0 ;
+    _prev_x = 0 ;
+    _prev_y = 0 ;
+    _prev_z = 0 ;
+    
+    _interval = 30 ;
+}
+
+edge_accel::~edge_accel(void)
+{
+    delete _accel ;
+}
+
+void    edge_accel::reset(void) 
+{
+    clear_value() ;
+    edge_sensor::reset() ;
+}
+
+#if 0
+void    edge_accel::prepare(void) 
+{
+//    printf("accel prepare\n") ;
+}
+#endif
+
+int    edge_accel::sample(void) 
+{
+    int result ;
+    float theValue = 0.0 ;
+    if (_sample_count > 1) { /* if sample is 1 or less, no data */
+        _num_sampled = _sample_count - 1 ;
+        theValue = (float)_accumulation / (float)(_num_sampled) ;
+        result = 0 ; /* success */
+    } else {
+        result = 1 ; /* fail! */
+    }
+    _value = theValue / 4096.0 ;
+    _sampled_time = edge_time ;
+    _sample_count = 0 ;
+    _accumulation = 0 ;
+    return( result ) ;
+}
+
+int    edge_accel::deliver(void) 
+{
+    int result ;
+    char timestr[16] ;
+    
+    print_time(_sampled_time) ;
+//    _value = get_value() ;
+    printf(" accel: %.3f [%d samples]\n", _value, _num_sampled) ;
+    time2seq(_sampled_time, timestr) ;
+    sprintf(_str_buf,
+        "{\"DEVICE\":\"ACCEL\",\"PN\":\"MMA8451Q\",\"VAL_X\":\"%.3f\",\"VAL_Y\":\"0\",\"VAL_Z\":\"0\",\"UNIT\":\"g\",\"T\":\"%s\",\"E\":\"%d\"}",
+        _value, timestr, _error_count) ;
+    result = afero->setAttribute(1, _str_buf) ;
+
+    return( result == afSUCCESS ) ;
+}
+
+int accel_v2y(float value, edge_chart_type *p)
+{
+    int y ;
+    if (value < p->min) {
+        value = p->min ;
+    } else if (value > p->max) {
+        value = p->max ;
+    }
+    y = p->top + p->height/2 - 1
+        - (int)((p->height - 2) * value /(p->max - p->min)) ;
+    return( y ) ;
+}
+
+void edge_accel::show(void)
+{
+    int x, y ;
+    edge_chart_type *p = &edge_chart[0] ; /* edge_chart for accel */
+    reset_watch_dog() ;
+    if (display) {
+        switch(display_mode) {
+        case DISPLAY_MODE_SUMMARY:
+            display->BusEnable(true) ;
+            display->set_font((unsigned char*) Arial12x12);
+            display->set_font_zoom(2, 2) ;
+            display->foreground(White) ;
+            display->locate(EDGE_SUMMARY_X, EDGE_SUMMARY_TIME_Y) ;
+            displayTime(_sampled_time) ;
+//          display->locate(10, 5) ;
+//          display->printf(timestr) ;
+            display->locate(EDGE_SUMMARY_X, EDGE_SUMMARY_ACCEL_Y) ;
+            display->printf("Accel: %.3f [%4d]", _value, _num_sampled) ;
+            display->BusEnable(false) ;
+            reset_watch_dog() ;
+            break ;
+        case DISPLAY_MODE_CHART:
+            x = p->left + p->index + 1;
+            y = accel_v2y(_value, p) ;
+            display->BusEnable(true) ;
+            if (p->index == 0) {
+                draw_chart_frame(p) ;
+            }
+            display->pixel(x, y, White) ;
+            display->BusEnable(false) ;
+            p->index = (p->index + 1) % (p->width - 2) ;
+            break ;
+        default:
+            break ;
+        }
+    }
+    clear_value() ;
+    reset_watch_dog() ;
+}
+
+int edge_accel::accum(void)
+{
+    int result ;
+    int16_t value[3] ;
+
+    if (_enable) {
+       result = _accel->getAllRawData(value) ;
+       
+        if (result == 0) { /* success */
+            if (_sample_count != 0) { /* first data does not have prev_data */
+                    _accumulation +=
+                    abs(_prev_x - value[0])
+                    + abs(_prev_y - value[1])
+                    + abs(_prev_z - value[2]) ; 
+            }
+            
+            _sample_count++ ;
+    
+            _prev_x = value[0] ;
+            _prev_y = value[1] ;
+            _prev_z = value[2] ;
+        }
+    }
+        
+    return( result ) ;
+}
+
+void edge_accel::clear_value(void)
+{
+    _sample_count = 0 ;
+    _accumulation = 0 ;
+    _prev_x = 0 ;
+    _prev_y = 0 ;
+    _prev_z = 0 ;
+}
+
+
+        
\ No newline at end of file