device reset after failed DHCP request to recognize dead ethernet module

reset.cpp

@@ -0,0 +1,61 @@
+/*
+ * reset.cpp
+ *
+ *  Created on: 14.05.2015
+ *      Author: wn
+ */
+
+#include <Streaming.h>
+
+const uint8_t POWER_LED = 4;
+
+
+void resetDevice() {
+  while (true) {
+    digitalWrite(POWER_LED, LOW);
+    delay(100);
+    digitalWrite(POWER_LED, HIGH);
+    delay(100);
+  }
+}
+
+
+
+void watchdogReset() {
+  static uint32_t last = 0;
+  static uint16_t maxTmroutl = 0;
+
+  // watchdog refresh
+  cli();
+  WDOG_REFRESH = 0xa602;
+  WDOG_REFRESH = 0xb480;
+  sei();
+
+  uint32_t now = millis();
+  if (last + 1000 < now) {
+    last = now;
+    uint16_t h = WDOG_TMROUTH;
+    uint16_t l = WDOG_TMROUTL;
+    maxTmroutl = (maxTmroutl > l) ? maxTmroutl : l;
+    uint16_t c = WDOG_RSTCNT;
+
+    Serial << "WDog, h: " << _HEX(h) << ", l: " << _HEX(l) << ", c: " << _HEX(c) << ", m: " << _HEX(maxTmroutl) << endl;
+  }
+}
+
+
+extern "C" {
+  void startup_early_hook( ) __attribute__ ((weak));
+  void startup_early_hook() {
+    // enable watchdog
+    WDOG_UNLOCK = WDOG_UNLOCK_SEQ1;
+    WDOG_UNLOCK = WDOG_UNLOCK_SEQ2;
+
+    // one minute
+    WDOG_TOVALL = 0xea60;
+    WDOG_TOVALH = 0;
+    WDOG_PRESC =  0;
+
+    WDOG_STCTRLH = WDOG_STCTRLH_WDOGEN | WDOG_STCTRLH_ALLOWUPDATE | WDOG_STCTRLH_STOPEN | WDOG_STCTRLH_WAITEN;
+  }
+} // extern "C"