Add valve example

Used for gardena valves with 9V power supply.

examples/osd/arduino-valve/resource_valve.c

@@ -0,0 +1,69 @@
+/**
+ * \file
+ *      Resource for Arduino PWM
+ * \author
+ *      Ralf Schlatterbeck <rsc@runtux.com>
+ *
+ * \brief get/put pwm and period for LED pin
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "contiki.h"
+#include "jsonparse.h"
+#include "er-coap.h"
+#include "generic_resource.h"
+#include "Arduino.h"
+#include "valve.h"
+
+uint8_t valve;
+
+int valve_from_string (const char *name, const char *uri, const char *s)
+{
+    uint32_t tmp = strtoul (s, NULL, 10);
+    if (tmp) {
+      tmp = 1;
+    }
+    if (tmp != valve) {
+        digitalWrite (ENABLE_PIN, HIGH);
+        if (tmp) {
+            digitalWrite (BRIDGE1_PIN, HIGH);
+            digitalWrite (BRIDGE2_PIN, LOW);
+            clock_delay_msec (250);
+            //clock_delay_msec (2500);
+            digitalWrite (BRIDGE1_PIN, LOW);
+            digitalWrite (ENABLE_PIN,  LOW);
+        } else {
+            digitalWrite (BRIDGE1_PIN, LOW);
+            digitalWrite (BRIDGE2_PIN, HIGH);
+            clock_delay_msec (62);
+            //clock_delay_msec (2500);
+            digitalWrite (BRIDGE2_PIN, LOW);
+            digitalWrite (ENABLE_PIN,  LOW);
+        }
+    }
+    valve = tmp;
+    return 0;
+}
+
+size_t
+valve_to_string (const char *name, const char *uri, char *buf, size_t bufsize)
+{
+  return snprintf (buf, bufsize, "%d", valve);
+}
+
+GENERIC_RESOURCE \
+    ( valve
+    , VALVE
+    , valve-status
+    , 0
+    , valve_from_string
+    , valve_to_string
+    );
+
+/*
+ * VI settings, see coding style
+ * ex:ts=8:et:sw=4
+ */