Excel Video 120 finishes our speedometer by adding the needle. To put the needle on the speedometer, you need to add another data series to the chart. Fortunately, we set up all of the information we needed in Excel Video 117, so we just need to add that data to the chart. The key is to change the chart type after adding the data. The outer dial is a doughnut chart. The needle needs to be a pie chart. Make sure you get your chart oriented properly so that the needle is pointing to the correct location on the dial by rotating the pie chart to match the doughnut chart we set up in the last video.
You’ll also need to hide all of the series (change the fill to no fill) except for the needle, which I make black. The black needle is the only series to show on the inner pie chart. With both the doughnut and the pie charts working together, you can now change one number and make the entire speedometer work.
This is fairly complicated stuff (and Excel Video 121 goes even further!) but even if you don’t use speedometers in your dashboards, there are several charting concepts in these videos that will prove helpful as you get more familiar with charts. We’ll use the idea of hiding (no fill) series again soon in another application.
