diff --git a/candatagrid.cpp b/candatagrid.cpp
index 7685597..090c203 100644
--- a/candatagrid.cpp
+++ b/candatagrid.cpp
@@ -3,6 +3,7 @@
 
 #include <QPainter>
 #include <QDebug>
+#include <QMouseEvent>
 
 CANDataGrid::CANDataGrid(QWidget *parent) :
     QWidget(parent),
@@ -19,6 +20,25 @@ CANDataGrid::~CANDataGrid()
     delete ui;
 }
 
+void CANDataGrid::mousePressEvent(QMouseEvent *event)
+{
+    QPoint clickedPoint = event->pos();
+    if (event->button() == Qt::LeftButton)
+    {
+        //qDebug() << "Mouse Loc " << clickedPoint;
+        clickedPoint -= upperLeft;
+        if (clickedPoint.x() < 0 || clickedPoint.y() < 0)
+        {
+            //qDebug() << "Clicked outside the grid you wanker";
+            return;
+        }
+        int x = clickedPoint.x() / gridSize.x();
+        int y = clickedPoint.y() / gridSize.y();
+        //qDebug() << "Grid square clicked " << x << " " << y;
+        emit gridClicked(x,y);
+    }
+}
+
 void CANDataGrid::paintEvent(QPaintEvent *event)
 {
     int x, y;
@@ -111,7 +131,11 @@ void CANDataGrid::paintEvent(QPaintEvent *event)
             //painter.fillRect(viewport.left() + (x+2) * xSector, viewport.top() + (y+2) * ySector, xSector, ySector, redBrush);
             painter.drawRect(viewport.left() + (x+2) * xSector, viewport.top() + (y+2) * ySector, xSector, ySector);
         }
-    }             
+    }
+    upperLeft.setX(viewport.left() + 2 * xSector);
+    upperLeft.setY(viewport.top() + 2 * ySector);
+    gridSize.setX(xSector);
+    gridSize.setY(ySector);
 }
 
 void CANDataGrid::setReference(unsigned char *newRef, bool bUpdate = true)
diff --git a/candatagrid.h b/candatagrid.h
index 1881951..4177ab5 100644
--- a/candatagrid.h
+++ b/candatagrid.h
@@ -18,10 +18,17 @@ public:
     void setReference(unsigned char *, bool);
     void updateData(unsigned char *, bool);
 
+protected:
+    void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
+
+signals:
+    void gridClicked(int x,int y);
+
 private:
     Ui::CANDataGrid *ui;
     unsigned char refData[8];
     unsigned char data[8];
+    QPoint upperLeft, gridSize;
 };
 
 #endif // CANDATAGRID_H
diff --git a/dbcsignaleditor.cpp b/dbcsignaleditor.cpp
index d6e1b59..0f547be 100644
--- a/dbcsignaleditor.cpp
+++ b/dbcsignaleditor.cpp
@@ -29,6 +29,7 @@ DBCSignalEditor::DBCSignalEditor(DBCHandler *handler, QWidget *parent) :
     }
 
     connect(ui->signalsList, SIGNAL(currentRowChanged(int)), this, SLOT(clickSignalList(int)));
+    connect(ui->bitfield, SIGNAL(gridClicked(int,int)), this, SLOT(bitfieldClicked(int,int)));
 }
 
 DBCSignalEditor::~DBCSignalEditor()
@@ -89,6 +90,10 @@ void DBCSignalEditor::fillSignalForm(DBC_SIGNAL *sig)
     }
 
     endBit = startBit + sig->signalSize - 1;
+    if (endBit > 63)
+    {
+        endBit = 63;
+    }
 
     bitpattern[startBit / 8] |= 1 << (startBit % 8);
     ui->bitfield->setReference(bitpattern, false);
@@ -155,3 +160,12 @@ void DBCSignalEditor::clickSignalList(int row)
     fillValueTable(thisSig);
 
 }
+
+void DBCSignalEditor::bitfieldClicked(int x, int y)
+{
+    int bit = (x) + (y * 8);
+    DBC_SIGNAL *thisSig = dbcHandler->findSignalByIdx(dbcMessage, ui->signalsList->currentRow());
+    if (thisSig == NULL) return;
+    thisSig->startBit = bit;
+    fillSignalForm(thisSig);
+}
diff --git a/dbcsignaleditor.h b/dbcsignaleditor.h
index d19e127..62daa43 100644
--- a/dbcsignaleditor.h
+++ b/dbcsignaleditor.h
@@ -20,6 +20,7 @@ public:
 
 private slots:
     void clickSignalList(int);
+    void bitfieldClicked(int x, int y);
 
 private:
     Ui::DBCSignalEditor *ui;