We have an interesting opportunity to evaluate Ootsidebox's 3DPad. 3DPad is an Arduino shield to implement a touchless gesture controller.
Ootsidebox blog has comprehensive material to start and play 3DPad. For your convenience, useful links are collected below with some comments.
3DPad Getting started guide
- In order to make 3Dpad work correctly, you need a 12V DC power supply (mandatory). 3DPad won't work correctly without it. After you upload Arduino firmware and launch a serial monitor you will see something like this which shows that 3DPad is working.
3DPad's demo software - Processing
- After you setup 3DPad, you may want to visually see how it works. 3DPad comes with a visualization software built by Processing environment. Although Processing 2.1.1 is mentioned in the link, Processing 2.2.1 also works well with 3DPad.
- In our test, the Processing code outputs following error message. However, it does not affect the operation of the software. Just ignore it and go forward to connect to 3DPad.
Now hover your finger above the pad and the visualization software will visually show your 3D gestures.
3DPad's demo software - VB6
- This visualization software is written in VB6. Since it only supports French at this time, we skipped testing it.
And here are more links for your deeper understanding of 3DPad.
Looking deeper in 3DPad's Hardware
Thanks Jean Noel to share this gorgeous device!
Amir Bolzman shared an interesting project using the Snowboard. He transformed the Snowboard into a musical instrument by combining Max/MSP.
Snowboard can measure force map across an FSR matrix array sensor. This unique feature of Snowboard is very useful if you are interested in implementing a pressure distribution measurement system (a.k.a pressure mapping system).
By default, visualization software of Snowboard shows you 3D force map.
However, you might need to get a 2D force map image. In this case, press '2' key, then the software changes its visualization mode from 3D to 2D force image.
If you feel that the 2D force map image is too weak, then use up/down arrow keys to control the image strength. Upper arrow key will strengthen the signal and the visibility of the 2D force map will be more improved.
Adding a single zone FSR (Force Sensitive Resistor) sensor is pretty simple thanks to the Snowboard's onboard force touch controller. This force touch controller is able to handle up to 160 single zone FSR sensors simultaneously with total scanning time less than 20 ms (120 us for each single sensor). This onboard controller always scan 160 sensing points when requested. However, in some case, you just want to use one or two FSRs and very fast response from them.
The easiest way to achieve this is to combine the Arduino and reference resistors in the Snowboard.
Let's first start with an example. Wire your FSR and the Snowboard as shown below.
It is convenient to use a small breadboard to implement the wiring above.
Then, upload the following code to the Snowboard.
Run Serial Monitor from Arduino IDE. Squeeze the FSR sensor. You can see that FSR reading is changed according the applied pressure. Speed of reading a single zone FSR sensor is at most 120 us which is quite fast enough for most applications (such as musical instrument).
Now we are in a position to know how it works. On the Snowboard, there are An pins which is part of Snowboard's connectors for force matrix sensors.
These pins are connected to 10 kOhm reference resistor as shown below.
According to the wiring above, an equivalent circuit is constructed as follows. D8 drives the whole circuit by applying 5V. Due to the serial connection of FSR and the 10 kOhm reference resistor, the applied +5V is divided across the two resistors, i.e. FSR and R1. The voltage acroos R1 is measured by A0 (analog input) pin of Snowboard whose value is
A0 (V) = 5 * R1 / (R_FSR + R1)
where R_FSR is the resistane of FSR sensor. It should be noted that this value is decresed according to the applied pressusre. When this voltage is measured by A0 (analog pin), this value is digitized between 0 and 1024. 0 and 1024 correspond to 0V and +5V, respectively.
Since there are six analog pins on the Snowboard, you can attach 6 FSR sensors with this approach. If you need to attach more FSR sensors, then use this method.
Here we are experimenting with a flexible piezoresistive material to be used with the Snowboard. This work is based on the needs of a local university lab.
We had a question from our customers if the Snowboard can be used with a single zone FSR (force sensing resistor) sensor. An answer was given in our last blog post and today we will go further with this issue.
Shortly speaking, the Snowboard can work with upto 160 single zone FSR sensors. All you need to do is to connect two ends of a sensor to appropriate pins of the Snowboard - One end to D pin and the other to A pin. D pins and A pins are configured as shown in the picture below:
In this post, we will add 3 single zone FSR sensors to the Snowboard.
Add them, upload a firmware and run a visualization application according to this instruction. Press each sensor and you can see the visual response of each sensor.
When you touch all of these sensors, the Snowboard can measure their responses simultaneously.