I ran through the tutorial (a month ago) setting up an agent and I admit I haven’t tried yet (should probably do so before posting, I know) but I’ve been thinking about using a small add-on board I designed with a Bosch BME280 (pressure, temperature, humidity) sensor, an ST RTC (with alarm interrupt), and a super cap battery backup that keeps the RTC going even without power to make a weather data logger/ iPhone updater. I would like to accomplish two tasks. One is to somehow use the RTC alarm to turn on the IMP, the other is to periodically send the sensor data to a web browser or iPhone or multiple of these. The first one might not be necessary since the IMP can apparently be programmed to sleep and wake up with a user-specified duty cycle. The IMP I am using has an LDO voltage regulator with an enable that could be activated by the RTC alarm, turning on the IMP, which would start the sensors, gather the data, publish it then disable the LDO. I am just musing if this strategy would extend the battery life or even makes sense. It is probably sufficient just to have the IMP sleep and periodically wake to do the same data collection and publication, since the current draw of the non-IMP part of the device (i.e., the sensors and RTC) would not be more than ~100 microAmps or so. The second is probably a straightforward application of agency. Being new to all of this, I wonder if there is an example sufficiently close to the data spewing application for me to study and copy?
Not sure it makes sense to power the imp off fully between readings; without the power gate on wifi you’re looking at ~50uA when sleeping, with the power gate more like 4-6uA - and that includes RTC and 4k nv table backup. See the imp003 app notes for wiring up the power gate (imp001 and 002 have this gate internally already).
Most batteries have fairly significant self discharge, so it’s really diminishing returns when you’re already in the single digit microamp range to drive lower.
If you take a look at the Nora reference design you’ll see a 2xAA powered environmental sensor with very good battery life. You can also buy these for $50 from Amazon.com.