Eric Fossum / Mbed 2 deprecated SprinklerTimer

I needed a device to time my sprinklers, because I had been forgetting to turn them off. So I made a very simple program to turn them off after 45 minutes. Future versions will have an array of outputs, so you can run sections with one button push. Hardware: Either board should work, I used the LPC1768. You will also need a solenoid to control the water, I am testing a 12V rainbird valve with a relay and 12V power supply.

Dependencies:   PinDetect mbed

Sprinkler Timer

I needed a device to time my sprinklers, because I had been forgetting to turn them off. So I made a very simple program to turn them off after some number of minutes.

Hardware

• Tested on the LPC1768
  • Either board should work
• You will also need some way of controlling the flow of water (like a solenoid valve and a relay). My test equipment:
  • 12V Rainbird valve (Rain Bird 3/4-Inch Sprinkler System Automatic In-Line Valve)
  • relay (SainSmart 2 channel relay)
  • 12V power supply (Replacement LCD Monitor Ac Adapter 12v 5a)
• Some Button for start/stop
• Some way of powering the board (maybe someone can help me power it from the 12v supply)

Connections

Button:

• One side to pin 5
• the other to Vout

Relay:

• Vcc to Vout
• Gnd to ground
• IN1 to pin 6

Directions/Use

• The button will start the sprinkler when it is off and vice versa.
• Once started if not interrupted, the sprinkler shall run for 25 minutes.

Future

Future versions will have an array of outputs, so you can run sections with one button push.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Mon Jan 21 16:01:52 2013 +0000
@@ -0,0 +1,50 @@
+#include "mbed.h"
+#include "PinDetect.h"
+
+DigitalOut myLed(LED1);
+DigitalOut solenoid(p6);
+
+PinDetect button(p5);
+
+Timer timer;
+
+bool enable = 0;
+int timeInMinutes = 45;
+
+void StartStop() {
+    // Enabled = !Enabled
+    if(solenoid.read()) {
+        // Turn off
+        timer.stop();
+        solenoid = 0;
+    } else {
+        // Turn on
+        timer.reset();
+        timer.start();
+        solenoid = 1;
+    }
+}
+
+int main() {
+    // Set button interrupt w/PullDown and 20ms sample
+    button.mode(PullDown);
+    button.attach_asserted_held(&StartStop);
+    button.setSampleFrequency();
+    
+    // Infinite loop
+    while(1) {
+        // Stop if time > 45 Mins
+        if(timer.read() > timeInMinutes * 60) {
+            solenoid = 0;
+            timer.stop();
+        }
+        
+        // Slow pulse status LED when enabled
+        if(solenoid.read())
+            myLed = !myLed.read();
+        else
+            myLed = 0;
+        
+        wait(0.5);
+    }
+}