Allow external triggering of i2c sensor measurements - e.g. Interrupt support

[tyeth]

Describe the solution you'd like It would be nice to be able to trigger an I2C sensor reading based on an external thing (e.g. interrupt pin or feed/blockly triggered)

Describe alternatives you've considered Currently the interrupt pin can be used, but not to trigger an i2c sensor, only to submit values to feeds (which could be other outputs etc).

Additional context Good morning :wave: Just a thought I had while unpacking some new sensors from digikey that might noodle their way into seed form while you do blockly. I just got a Person sensor from Useful Sensors, has an interrupt pin for ppl detected, and gives a grid ref over i2c for a couple of faces). If I needed to pass up to 4 face coordinates back, what would be the best datatype / setup. I am thinking raw type gives 8 ints, so that would be face1x face1y etc. Not sure it's so useful at a 30sec polling (occupancy still interesting data), but combined with the interrupt trigger it would be next level. Currently we'd have to treat them as separate data, a digital input pin for interrupt could trigger things, and the last face data would be available from feed value (would be stale tho). Long term it would be nice to trigger i2c reads based on some external factor (interrupt pin / blockly)

[tyeth]

Just to say raised in meeting, as well as triggering i2c readings, suggested camera image taken by WS device,triggered by remote button/feed/blockly. Similarly Limor suggested GPS / geofencing could trigger the start of readings on a WS device.