Hi folks,
I'm looking for suggestions on achieving the lowest power, but accurate, timer to last around 6 months.
It will be at the bottom of the ocean and I have minimal real estate to fit the timer inside an acoustic device so a RTC is out of the question. This device will initially operate for an hour as confirmation on deployment and then sleep (off, powered by the PIC/mosfet) for a period of 180 days. After this the device will be powered up and remain so until its battery supply is exhausted (approx. 2 weeks).
I've looked at DT's Elapsed Timer but sleep command results in havoc with the interrupts it seems, so I'm thinking an SMD 12LF1840 running from a coin cell counting wake-ups from 10 second sleep events could be an avenue. Some quick and dirty code sees about 10uA average consumption using a 4Mhz crystal but speed isn't an issue, but power, size and accuracy is.
Does anyone have any suggestions other than above to offer?
Thanks and regards to all,
Bill
I'm looking for suggestions on achieving the lowest power, but accurate, timer to last around 6 months.
It will be at the bottom of the ocean and I have minimal real estate to fit the timer inside an acoustic device so a RTC is out of the question. This device will initially operate for an hour as confirmation on deployment and then sleep (off, powered by the PIC/mosfet) for a period of 180 days. After this the device will be powered up and remain so until its battery supply is exhausted (approx. 2 weeks).
I've looked at DT's Elapsed Timer but sleep command results in havoc with the interrupts it seems, so I'm thinking an SMD 12LF1840 running from a coin cell counting wake-ups from 10 second sleep events could be an avenue. Some quick and dirty code sees about 10uA average consumption using a 4Mhz crystal but speed isn't an issue, but power, size and accuracy is.
Does anyone have any suggestions other than above to offer?
Thanks and regards to all,
Bill