La Suno / Mbed 2 deprecated afero_poc15_180403

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。

Diff: edge_utils/edge_mgr.cpp

Revision:
1:1af1fd910340
Parent:
0:d895cd1cd897
--- a/edge_utils/edge_mgr.cpp	Tue Apr 03 08:30:29 2018 +0000
+++ b/edge_utils/edge_mgr.cpp	Fri Apr 06 04:17:34 2018 +0000
@@ -322,7 +322,7 @@
  */ 
 #define I2C_UNLOCK_TRIAL_CYCLE 50
 
-void check_i2c_pins(PinName sda_pin, PinName scl_pin)
+void check_i2c_pins(PinName sda_pin, PinName scl_pin, int number)
 {
     DigitalIn *sda_in = 0 ; 
     DigitalIn *scl_in = 0 ;
@@ -330,8 +330,9 @@
     int count = 0 ;
     sda_in = new DigitalIn(sda_pin, PullUp) ;
     scl_in = new DigitalIn(scl_pin, PullUp) ;
+    printf("I2C%d pin ", number) ;
     if ((*sda_in == 0) || (*scl_in == 0)) { /* bus hang! */
-        printf("I2C pin hang detected, trying to clear\n") ;
+        printf("hang detected, trying to clear ... ") ;
         delete scl_in ;
         scl_in = 0 ;
         scl_out = new DigitalOut(scl_pin) ;
@@ -341,8 +342,13 @@
             *scl_out = 1 ;
             wait(0.01) ;
         }
+        if (*sda_in != 0) {
+            printf("Cleared!\n") ;
+        } else {
+            printf("Failed to Clear, proceeding\n") ;
+        }
     } else {
-        printf("I2C pin condition OK\n") ;
+        printf("condition OK\n") ;
     }
     if (sda_in) { delete sda_in ; }
     if (scl_in) { delete scl_in ; }
@@ -352,10 +358,10 @@
 void init_sensors(void)
 {
     printf("=== Initializing Sensor(s) ===\n") ;    
-    check_i2c_pins(PIN_I2C0_SDA, PIN_I2C0_SCL) ;
+    check_i2c_pins(PIN_I2C0_SDA, PIN_I2C0_SCL, 0) ;
     edge_i2c0 = new I2C(PIN_I2C0_SDA, PIN_I2C0_SCL) ;
     
-    check_i2c_pins(PIN_I2C1_SDA, PIN_I2C1_SCL) ;
+    check_i2c_pins(PIN_I2C1_SDA, PIN_I2C1_SCL, 1) ;
     edge_i2c1 = new I2C(PIN_I2C1_SDA, PIN_I2C1_SCL) ;
                 
     if (display) {