Replacing wired switch by bluetooth switch

[Olivier Scalbert]

Hi,

I am working on a project where there are moving devices. Devices can only move if a wired button is pressed. In fact, for security reasons, there are two buttons connected in series to a PCL.

We would like to replace the wired connection by a bluetooth connection, that is why we are looking around about the nRF51822. We have several constraints:

• there are several sets of (switch, moving device). They are not at the same location, but it is mandatory that a remote switch is dedicated to one moving device and one only !
• safety: communication should be safe and encrypted to avoid hacks;
• low energy aspects for the switch side.

Any info or pointers to ideas, design patterns that can be used for this project would be greatly appreciated !!!

Thanks in advance !

Olivier

[Olivier Scalbert]

Hi,

I have a question related to this thread ...

Let say that our system is composed of two parts:

• the mobile module (with the switch)
• the fixed module (connected to a safety PLC)

For different reasons, our system team would like to have the switch power on/off itself the mobile module. If the switch is not pressed, the mobile module is power off. If the switch is pressed, the mobile module is on.

So, conceptualy the message to transfer from the mobile to the fixed module is no more a kind of boolean (on/off), but a constant message telling "Hi, I am on", "Hi I am on", ... until next switch off

Do you have new advices ?

Thanks,

Olivier

[Ole Morten]

I don't think this changes anything, and you should be able to achieve this by just keep sending notifications as long as the button is pressed.