     }
     
     private func writeMatrixNow(matrix: String?) {
-        assert(!isWaitingForLedMatrixWriteResponse, "Cannot write matrix now, response from previous write request not yet received")
-        guard let ledMatrixCharacteristic = ledMatrixCharacteristic else { return }
+        assert(!isWaitingForMatrixWriteResponse, "Cannot write matrix now, response from previous write request not yet received")
+        guard let ledMatrixCharacteristic = matrixCharacteristic else { return }
         
         // Convert matrix string representation into byte representation
         let matrixBytes = NuimoLEDMatrix.matrixBytesForString(matrix ?? "")

            case kBatteryCharacteristicUUID:
                peripheral.readValueForCharacteristic(characteristic)
            case kLEDMatrixCharacteristicUUID:
                ledMatrixCharacteristic = characteristic
                delegate?.nuimoControllerDidDiscoverMatrixService?(self)
            default:
                break

    }
    
    internal func didConnect() {
        isWaitingForMatrixWriteResponse = false
        writeMatrixOnWriteResponseReceived = false
        // Discover bluetooth services
        peripheral.discoverServices(nuimoServiceUUIDs)
