'thought these IR distance / presence sensors might work well with a QAI, in situations where very-localised presence-sensing is wanted :
http://www.oomlout.co.uk/infra-red-d...283364ff2260f9
Infra Red Distance Sensor ... will return an analog voltage proportional to the distance between the sensor and an object in front of it ... signal ranges from 0.4 volts at 80cm to 3 volts at 10cm ... simple three wire interface (power & analog output) ... includes: distance sensor (SHARP GP2Y0A21YK) ...
current consumption is around 30mA ...
Various versions (various ranges, etc) of the sensor are also available - eg: from RS :
GP2Y0D21YK - 10-80cm type
http://www.sharpsma.com/Page.aspx/am...rt/GP2Y0D21YK/
http://uk.rs-online.com/web/search/s...D21YK&x=32&y=8
GP2Y0D21YK0F - 24cm type
http://www.sharpsma.com/Page.aspx/am.../GP2Y0D21YK0F/
http://uk.rs-online.com/web/search/s...21YK0F&x=0&y=0
GP2D150AJ00F - 3-30cm type
http://docs-europe.origin.electrocom...6b80a711a6.pdf
http://uk.rs-online.com/web/search/s...0AJ00F&x=0&y=0
Other, more basic PCB-mounting versions, current consumption around 7mA, also available :
GP2Y0D810Z0F - 100mm type
http://document.sharpsma.com/files/gp2y0d810z_e.pdf
http://uk.rs-online.com/web/search/s...810Z0F&x=0&y=0
GP2Y0D805Z0F - 50mm type
http://document.sharpsma.com/files/gp2y0d805z_e.pdf
http://uk.rs-online.com/web/search/s...805Z0F&x=0&y=0
plus, PCB to go with them, here :
http://www.pololu.com/catalog/product/1133
There are other versions, too - all are listed here (p.10) :
http://www.sharpsma.com/opto_docs/Op...rd_Sensors.pdf
NB: Key aspects of the QAI :
four-way analogue input ... multiplexed, non-isolated ... 0V to +5V ... eight-bits monotonic ... update rate ~30Hz ...
channels can be interrogated at any time ...
one of the four channels can be selected for Reflex functions ... signal level equals or exceeds ... equals or falls below ... exceeds user defined Delta limit (auto-datuming) ...
module-wide Reflex functions: time interval trigger ... 1-127 seconds / 1– 127 minutes ... module initialise trigger ...
user-defined trigger enabling pattern ...
each event trigger can generate a pre-defined response and/or several user-programmable responses ...
status indicator LED ...
12-15VDC ... 20mA (max) ...
0V, 5V (current limited) references provided for analogue inputs ...
ISTM the Reflex functionality might be v.useful (if it can be used like this) as a device for alerting Cortex without tying-up Cortex ... not sure how the so-called user-defined trigger enabling pattern works - ie: is the pattern defined, for individual inputs, in terms of voltage vs time (if so, might be v.useful for identifying & distinguishing between a variety of user inputs - moving hand towards meaning one thing, away another, for example, or wave-across once, twice, three-times, etc) ... ???