Proximity: add resolution of MB1003 device

Forkses · Feb 20, 2018 · b2ebba8 · b2ebba8
1 parent 998b353
commit b2ebba8
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Showing 2 changed files with 13 additions and 7 deletions.
diff --git a/lib/proximity.js b/lib/proximity.js
@@ -150,7 +150,12 @@ var Controllers = {
     toCm: {
       value: function(raw) {
         // http://www.maxbotix.com/articles/032.htm
-        return raw / 2;
+        //
+        // Datasheet available at https://www.maxbotix.com/documents/HRLV-MaxSonar-EZ_Datasheet.pdf
+        //
+        // From intro in page 1
+        // 'This sensor line features 1-mm resolution, .....'
+        return toFixed(raw / 2, 1);
       }
     }
   },

diff --git a/test/proximity.js b/test/proximity.js
@@ -656,15 +656,16 @@ exports["Proximity: MB1003"] = {
   MB1003: function(test) {
     var callback = this.analogRead.args[0][1];
 
-    test.expect(4);
+    test.expect(5);
 
     // 500 is an actual reading at ~250cm
-    callback(500);
+    callback(507);
 
-    test.equals(Math.round(this.proximity.centimeters), 250);
-    test.equals(Math.round(this.proximity.cm), 250);
-    test.equals(Math.round(this.proximity.inches), 98);
-    test.equals(Math.round(this.proximity.in), 98);
+    test.equals(Math.round(this.proximity.centimeters), 254);
+    test.equals(Math.round(this.proximity.cm), 254);
+    test.equals(Math.round(this.proximity.inches), 99);
+    test.equals(Math.round(this.proximity.in), 99);
+    test.equals(digits.fractional(this.proximity.centimeters), 1);
 
     test.done();
   },