comms and util files

scada-common/util.lua

@@ -0,0 +1,29 @@
+-- timestamped print
+function print_ts(message)
+    term.write(os.date("[%H:%M:%S] ") .. message)
+end
+
+-- ComputerCraft OS Timer based Watchdog
+-- triggers a timer event if not fed within 'timeout' seconds
+function new_watchdog(timeout)
+    local self = { 
+        _timeout = timeout, 
+        _wd_timer = os.startTimer(_timeout)
+    }
+
+    local get_timer = function ()
+        return self._wd_timer
+    end
+    
+    local feed = function ()
+        if self._wd_timer ~= nil then
+            os.cancelTimer(self._wd_timer)
+        end
+        self._wd_timer = os.startTimer(self._timeout)
+    end
+
+    return {
+        get_timer = get_timer,
+        feed = feed
+    }
+end