Add dim command

hardware/sensehat/README.md

@@ -118,3 +118,9 @@ The following message properties can be used to customise the appearance:
   - `msg.color` - the colour of the text, default: `white`
   - `msg.background` - the colour of the background, default: `off`
   - `msg.speed` - the scroll speed. A value in the range 1 (slower) to 5 (faster), default: `3`
+
+#### Set the screen brightness
+
+Format: `D<level>`
+
+`level` must be 0 (low) or 1 (high).

hardware/sensehat/package.json

@@ -1,6 +1,6 @@
 {
     "name"          : "node-red-node-pi-sense-hat",
-    "version"       : "0.0.5",
+    "version"       : "0.0.6",
     "description"   : "A Node-RED node to interact with a Raspberry Pi Sense HAT",
     "repository" : {
         "type":"git",

hardware/sensehat/sensehat.html

@@ -130,6 +130,10 @@ To scroll a single character, append a blank space after it - <code>"A "</code>.
     <li><code>msg.background</code> - the colour of the background, default: <code>off</code></li>
     <li><code>msg.speed</code> - the scroll speed. A value in the range 1 (slower) to 5 (faster), default: <code>3</code></li>
 </ul>
+
+<p><b>Set the screen brightness</b></p>
+<p>Format: <code>D&lt;level&gt;</code></p>
+<p><code>level</code> must be 0 (low) or 1 (high).</p>
 </script>
 <script type="text/javascript">
     RED.nodes.registerType('rpi-sensehat in',{

hardware/sensehat/sensehat.js

@@ -232,8 +232,8 @@ module.exports = function(RED) {
             HAT.close(this,done);
         });
         var handleTextMessage = function(line,msg) {
-            var textCol = colours.getRGB(msg.color||msg.colour);
+            var textCol = colours.getRGB(msg.color||msg.colour)||"255,255,255";
-            var backCol = colours.getRGB(msg.background);
+            var backCol = colours.getRGB(msg.background)||"0,0,0";
             var speed = null;
             if (!isNaN(msg.speed)) {
                 speed = msg.speed;
@@ -245,6 +245,7 @@ module.exports = function(RED) {
                     command += ","+backCol;
                 }
             }
+
             if (speed) {
                 var s = parseInt(speed);
                 if (s >= 1 && s <= 5) {
@@ -325,6 +326,8 @@ module.exports = function(RED) {
                             command = line.toUpperCase();
                         } else if (/^F(H|V)$/i.test(line)) {
                             command = line.toUpperCase();
+                        } else if (/^D(0|1)$/i.test(line)) {
+                            command = line.toUpperCase();
                         } else {
                             command = handleTextMessage(line,msg);
                         }

hardware/sensehat/sensehat.py

@@ -21,6 +21,7 @@
 #  F[H|V] - flip horizontal|vertical
 #  X[0|1] - high frequency reporting (accel/gyro/orientation/compass) off|on
 #  Y[0|1] - low frequency reporting (temperature/humidity/pressure) off|on
+#  D[0|1] - Set light level low|high
 #
 # Outputs:
 #  Xaccel.x,y,z,gyro.x,y,z,orientation.roll,pitch,yaw,compass
@@ -126,6 +127,11 @@ def process_command(data):
       lf_enabled = False
     else:
       lf_enabled = True
+  elif data[0] == "D":
+    if data[1] == '0':
+      SH.low_light = True
+    else:
+      SH.low_light = False
   else:
     if threading.activeCount() == 2:
       scroll.interrupt()