         }
     }
 
+    public override var pull: GPIOPull {
+        set(pull) {
+            if !exported {enableIO(id)}
+            setGpioPull(pull)
+        }
+        get{
+            fatalError("Parameter cannot be read.")
+        }
+    }
+
     public override func isMemoryMapped() -> Bool {
         return true
     }

        let ptr = gpioBasePointer.advanced(by: id/10)       // GPFSELn 0..5
        let d = (ptr.pointee & (7<<((UInt(id)%10)*3)))
        return (d == 0) ? .IN : .OUT
    }

    private func gpioGet() -> Int {

        get {
            if !exported {enableIO(id)}
            return getIntValue("gpio"+String(id)+"/active_low")==0
        }
    }

    public var pull: GPIOPull {
        set(dir) {
            fatalError("Unsupported parameter.")
        }
        get{
            fatalError("Parameter cannot be read.")
        }
    }

