diff --git a/src/abstractreader.cpp b/src/abstractreader.cpp
new file mode 100644
--- /dev/null
+++ b/src/abstractreader.cpp
@@ -0,0 +1,46 @@
+/*
+  Copyright © 2016 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "abstractreader.h"
+
+AbstractReader::AbstractReader(QIODevice* device, ChannelManager* channelMan, QObject *parent) :
+    QObject(parent)
+{
+    _device = device;
+    _channelMan = channelMan;
+
+    // initialize sps counter
+    sampleCount = 0;
+    samplesPerSecond = 0;
+    QObject::connect(&spsTimer, &QTimer::timeout,
+                     this, &AbstractReader::spsTimerTimeout);
+    // TODO: start sps timer when reader is enabled
+    spsTimer.start(SPS_UPDATE_TIMEOUT * 1000);
+}
+
+void AbstractReader::spsTimerTimeout()
+{
+    unsigned currentSps = samplesPerSecond;
+    samplesPerSecond = (sampleCount/numOfChannels())/SPS_UPDATE_TIMEOUT;
+    if (currentSps != samplesPerSecond)
+    {
+        emit samplesPerSecondChanged(samplesPerSecond);
+    }
+    sampleCount = 0;
+}