time = event.time - now;
ppm = (int) ((Long) event.payload).longValue();
x1 = (int) (time/1000);
y1 = ppm;
chart.setColor("AA8888");
if (x0 < 0) chart.chartLine(ChartPlotter.DIMENSION_BOTTOM, ChartPlotter.DIMENSION_ANOT0, x0, y0, x1, y1);
chart.setColor("AA2222");
chart.chartDot(ChartPlotter.DIMENSION_BOTTOM, ChartPlotter.DIMENSION_ANOT0, x1, y1, 2, ppm + " PPM", 0);
x0 = x1; y0 = y1;
}
}