From e38b321c336ea0ecb4b6f7030bbf3435dca310c6 Mon Sep 17 00:00:00 2001
From: Dave C-J <dave@conway-jones.co.uk>
Date: Tue, 8 Apr 2014 16:04:13 +0100
Subject: [PATCH] Tweak to Pi GPIO node to throw exceptions more in line with
 latest thinking

---
 nodes/core/hardware/36-rpi-gpio.js | 39 ++++++++++++++----------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/nodes/core/hardware/36-rpi-gpio.js b/nodes/core/hardware/36-rpi-gpio.js
index 4c6bae7aa..05195fc02 100644
--- a/nodes/core/hardware/36-rpi-gpio.js
+++ b/nodes/core/hardware/36-rpi-gpio.js
@@ -19,14 +19,12 @@ var util = require("util");
 var exec = require('child_process').exec;
 var fs =  require('fs');
 
-if (!fs.existsSync("/usr/local/bin/gpio")) {
-    exec("cat /proc/cpuinfo | grep BCM27",function(err,stdout,stderr) {
-        if (stdout.indexOf('BCM27') > -1) {
-            util.log('[36-rpi-gpio.js] Error: Cannot find Wiring-Pi "gpio" command. http://wiringpi.com/download-and-install/');
-        }
-        // else not on a Pi so don't worry anyone with needless messages.
-    });
-    return;
+if (!fs.existsSync("/dev/ttyAMA0")) { // unlikely if not on a Pi
+    throw "Info : Ignoring Raspberry Pi specific node.";
+}
+
+if (!fs.existsSync("/usr/local/bin/gpio")) { // gpio command not installed
+    throw "Info : Can't find Raspberry Pi wiringPi gpio command.";
 }
 
 // Map physical P1 pins to Gordon's Wiring-Pi Pins (as they should be V1/V2 tolerant)
@@ -103,6 +101,10 @@ function GPIOInNode(n) {
     else {
         this.error("Invalid GPIO pin: "+this.pin);
     }
+
+    this.on("close", function() {
+        clearInterval(this._interval);
+    });
 }
 
 function GPIOOutNode(n) {
@@ -133,6 +135,10 @@ function GPIOOutNode(n) {
     else {
         this.error("Invalid GPIO pin: "+this.pin);
     }
+
+    this.on("close", function() {
+        exec("gpio mode "+this.pin+" in");
+    });
 }
 
 exec("gpio mode 0 in",function(err,stdout,stderr) {
@@ -145,17 +151,8 @@ exec("gpio mode 0 in",function(err,stdout,stderr) {
     exec("gpio mode 4 in");
     exec("gpio mode 5 in");
     exec("gpio mode 6 in");
-    exec("gpio mode 7 in",function(err,stdout,stderr) {
-        RED.nodes.registerType("rpi-gpio in",GPIOInNode);
-        RED.nodes.registerType("rpi-gpio out",GPIOOutNode);
-
-        GPIOInNode.prototype.close = function() {
-            clearInterval(this._interval);
-        }
-
-        GPIOOutNode.prototype.close = function() {
-            exec("gpio mode "+this.pin+" in");
-        }
-
-    });
+    exec("gpio mode 7 in");
 });
+
+RED.nodes.registerType("rpi-gpio in",GPIOInNode);
+RED.nodes.registerType("rpi-gpio out",GPIOOutNode);