Chartjs-Chartjs Array.join

According to http://www.chartjs.org/docs/
data field is an Array so your syntax should be:

var datenbarchart = obj;

…

var barChartData = {
    labels : [ obj1[0], obj1[1], obj1[2], obj1[3], obj1[4], obj1[5], obj1[6]],
    datasets : [
        {
            fillColor: "rgba(151,187,205,0.5)",
        strokeColor: "rgba(151,187,205,0.8)",
        highlightFill: "rgba(151,187,205,0.75)",
        highlightStroke: "rgba(151,187,205,1)",
            data : datenbarchart
        }
    ]

}