Author Topic: Low Power consumption with stock Moteino  (Read 5885 times)

MoebiusL

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Re: Low Power consumption with stock Moteino
« Reply #15 on: October 01, 2016, 03:37:30 AM »
Thanks for the update ChemE. I had a look but I'm just worried that using such approach and the time consumed for the MCU to startup (crystal + waiting) + bootloader will bee too much. I think you can change the fuses from 65ms to 4ms delay start-up, but still 4ms wasted compared to only 60uS wake-up time from sleep. I think you can set the fuse to 0ms, but sounds too risky - maybe I'm just being too cautions.  ::)

Anyway, this is sounds a great approach for applications that require a fixed running time and only wake up after longer periods to compensate the start-up time. My application requires a bit more o flexibility regarding how long it will wake up and run, so having the power being shutdown by an external hardware would make very difficult to code, specially without things being preserved in RAM.

I'm think the +-6uA via a step-up regulator still pretty good, specially running from a single AA, but certainly will do some trials removing the regulators and using the 2xAA Lithium batteries with sleeping mode.

joelucid

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Re: Low Power consumption with stock Moteino
« Reply #16 on: October 01, 2016, 04:43:41 AM »
Quote
I have not measured that b/c I don't have an oscilloscope.  I've searched rather extensively online and cannot turn up this missing information either. 

I measured this once:

https://lowpowerlab.com/forum/low-power-techniques/a-new-sleep-mode-using-225-na/msg11200/#msg11200

Took about 20ms for full radio initialization. When you sleep the radio instead it can be very quick (see post). I think overall whitehare is correct that 250nA in sleep for radio and 328p are hard to beat for most cases. Just use the tpl to wake the 328p instead of as load switch.

TomWS

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Re: Low Power consumption with stock Moteino
« Reply #17 on: October 01, 2016, 08:25:32 AM »
Quote
I have not measured that b/c I don't have an oscilloscope.  I've searched rather extensively online and cannot turn up this missing information either. 

I measured this once:

https://lowpowerlab.com/forum/low-power-techniques/a-new-sleep-mode-using-225-na/msg11200/#msg11200

Took about 20ms for full radio initialization. When you sleep the radio instead it can be very quick (see post). I think overall whitehare is correct that 250nA in sleep for radio and 328p are hard to beat for most cases. Just use the tpl to wake the 328p instead of as load switch.
I agree.  The crossover point for 328P & RFM69 is around a 30 minute duty cycle and, in either case, the currents are so insanely low that you're more likely to have some other failure rather than battery discharge. 

Also, if you're using a TPL to wake up (rather than power up), the TPL5010 is a better choice as this can serve as a reset watchdog as well.

Where the TPL5110 shines is when you're processor is not as low power in sleep mode. ESP8266 to take a random example, although this will take longer than 20mS to start up and connect.

Tom