I'm trying to add a wireless option to an existing product.
The requirement is to carry switch status information across a single room so range isn't a huge consideration. The switching frequency is very low i.e. whenever someone presses a button which will only happen a few times per minute at most so bandwidth isn't a major concern either.
What is of more concern is using a recognised standard as this product will need to be certified for use in a medical environment (I've done this before, I know how much fun that is ) and the ability to pair easily, ideally something like holding down a button on each end of the pair for x seconds to pair automatically. There could potentially be multiple pairs within range of each other so open pairing wouldn't be an option.
There will be an ATMega of some sort connected to either end of the pair.
I'm only getting started on the project. I'm looking at Bluetooth at the minute, probably the RN42 module from Microchip but just though I'd poll opinion to see if anyone would recommend looking at other protocols, Zigbee/Xbee, etc.?
Correct on both counts, the application is non-critical and non-diagnostic and I've control over the Arduinos.
My device takes a video feed from assorted medical devices and, when the consultant presses a trigger button, captures either a video or still image from the video feed.
These are for training and/or reporting purposes, not used for diagnostics hence the non-critical element
With regard to pairing, I would have a transmitter connected to the video producing device and a receiver connected to the video capture device. The actual video feed is being handled separately so it's only the trigger information I need to transmit.
The pairing would be to configure that transmitter device X is associated with receiver X so that when a trigger is pressed, the correct video capture device picks up the signal.
The ease of pairing requirement (it's more a nice to have than a hard requirement) is down to making replacing faulty devices as easy as possible.
If you have control of the transmitter and receiver you can easily arrange that an ID code is sent as part of every message. That would enable the receiver to satisfy itself that the message is legitimate. The ID code could be built in when you are programming the two devices.
Indeed the NRF24 transceivers have that sort of system in-built with their "pipe" system.
) and the ability to pair easily, ideally something like holding down a button on each end of the pair for x seconds to pair automatically. There could potentially be multiple pairs within range of each other so open pairing wouldn't be an option.