How to create proximity wall sensors with Electrode Pads
Learn how to create proximity wall sensors at the back
Although the Interactive Wall Kit was designed to have touch sensors, it’s also possible to create a capacitive proximity sensor with it. The user approaches the design with their hand but doesn’t touch it. The best material to use this with copper tape and creating sensors that are 20cm wide. If you want to create a touch capacitive sensor instead, please follow this touch wall sensors tutorial.
Proximity sensing is more delicate than touch sensing and is, therefore, more prone to noise. Make sure to not build the wall in close vicinity of any metal object.
Step 1 Create sensor
From the front, decide where the user is going to interact with your interactive wall. Create a sensor directly behind the wall in that same location. You want the sensor to be around 20cm in diameter, which you can mark out with a ruler. Then, using the copper tape, create a hatched sensor.
Step 2 Attach the Electrode Pad
In the centre of the sensor, where the tape creates a cross, attach the Electrode Pad with the self tapping screws. Make sure to screw the screws all the way in and straight, so that the connection between the pad and the copper tape is super tight.
Step 3 Apply the graphics
Now, apply the graphics at the front of your wall. You can either paint them or use vinyl.
Step 4 Test the sensor
Then, plug one end of the shielded cable into the Electrode Pad, the other into the Electrode Shield. Turn the Touch Board on, or reset it. When you turn the board on, don’t have your hand close to the sensor, as that influences the reading. Now, test your sensor by hovering your hand over the graphic. You should be able to trigger the sensor!
If you want to visualise the sensor and any detection, we recommend using the Grapher. Alternatively, you can use the sensor as a proximity switch and play an MP3 file.
Step 5 Next steps
Next, you want to replicate these steps for the other proximity sensors you want to create. With this method, you can measure about 5cm away from the surface. If you require a little bit more sensing distance, you can also create a hatched sensor at the front and connect it with the Electrode Pad using the machine screw and washers.
You can create smaller sensors, however, 20cm wide sensors give you the optimal sensing range, smaller sensors don’t detect as far.
You can also use the Grapher tool, to adjust the sensitivity of the sensor.