Magnetic Sensor connections
Possibilities for connecting sensor modules
Connecting the different modules is an essential part of the concept, because this “handeling” is responsible for the actual ‘programming’ of the modules. Therefore the modules must have connectors which are easy to connect to each other and sturdy enough to be plugged and unplugged multiple times.
5mm three-phase jack
A three-phase jack plug is a jack plug that is able to communicate three phases (in my situation these are the required 5V, Ground and Sensory data) all trough the same connector. This makes the three-phase jack an excellent connector for connecting a sensor.
Evaluation of the connector
Because of its small size, the connection of the sensor to the central box was weak. This resulted in noisy signals and in some situations in short-circuiting the connection. This is the main disadvantage of having three phases on the same pin; it allows for short-circuiting and both the 5V and ground signal disturb the sensory signal.
Tulip ‘audio’ plugs
Tulip audio plugs provide a sturdier and more powerful connection between the two than the previous three-phase connector does. The tulip plugs are therefore better suitable for our application.
Evaluation of the connector
This connector is often used in audio, which means it is a sturdy connector with a big connecting surface to provide maximal signal transmission. Sadly, it has only room for two phases per plug, so therefore I need to use two of these plugs for the connection.
Magnetic connecting surfaces
Enhancing the stability of a particular connector trough magnetism is a feature we see more and more these days. For example, Apple’s MacBook laptops (Source!) use magnetically enhanced power connectors to reduce the damage caused by tripping over the wire and to provide an easy
“snapping” mechanism for the user. Because of the benefit of “magnetically enhanced connectors” I will attempt to design my own variant and implement it in my sensor boxes.
Evaluation of the connector
The magnets ensure that the user will connect the boxes in the right way, and because of the way they will be integrated in the sensor box, it leaves no vulnerable connectors.
Conclusion
While at first, the three-phase jack plug seemed most suitable, I noticed that this plug was too small and fragile to provide a sturdy noise free connection between two big objects (sensor boxes).
The bigger and studier Tulip audio plugs however, where too big and sturdy to let the user regularly switch between the modules. Disconnecting these plugs costs quite some effort and after a whilewill damage the sensor boxes.
Finally, the magnets offered a fitting solution. Using multiple magnets created a stable connection between three pieces of copper-foil that form the connectors for the three signals.
I have made multiple sensor boxes and tested these to validate my connections.
Attached you will find puzzle.ai, which contains all press fit box blueprints which I used to laser the sensor boxes.
Next Steps
Finding out if these connectors are also suitable for output boxes (speakers, leds, servo motors). I have yet to design a suitable interface for these boxes, because output boxes all have to be driven in a different way.
