Day 8: A Controller
On the eighth day you will find a potentiometer behind the door. We are going to use it as voltage divider. You can set a voltage between 0 V and 3.3 V, which is measured by the board and sent to NodeRED. On top of to the functions of yesterday’s stairway light, you can also send the measured values.
As usual you can obtain today’s flow from here. Don’t forget to disable yesterday’s flow and you may need to adjust the send-IP. The flow of today also has a new node for the dashboard, namely a gauge to visually display the measured value.
Once you have today’s program enable, you will see a gauge element (a pointer) on the dashboard page that refreshes every two seconds and shows new readings. If you now turn the wheel of the potentiometer, these values will change. This measured value could be used for different applications such as to control the brightness of the LED or to set the lighting time of the staircase lighting; again, a typical smart home application.