Go Down

Topic: External 32 KHz timer2 in order to shutdown (Read 1 time) previous topic - next topic

GoForSmoke

Is there nowhere near an electric meter that you can plug a USB charger in?

I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

Nick Gammon


I will not need a like a calendar time ... but just to have the millis between last 2 pulses.


Why? Don't you just want to count the number of pulses over 5 minutes? If you want to know the number of watts, who cares when the pulse occurred, to the nearest millisecond?

dhenry

Quote
but just to have the millis between last 2 pulses.


Generally, if your duration between tasks is that short, you don't put your mcu into sleep: the restart of a crystal oscillator can be several ms on most mcus.

If that's what you truly want to do, look into msp430: their crystal oscillator is "instant on". Energy micro is a distant 2nd and other mcu oems are not even in the same universe with TI on that.

denisj


Is there nowhere near an electric meter that you can plug a USB charger in?

The problem is not the power, i just want to make it run from 2 X 1.5 Batts cause i'm sure it can run some mounts if i make it right ;-)


Why? Don't you just want to count the number of pulses over 5 minutes? If you want to know the number of watts, who cares when the pulse occurred, to the nearest millisecond?

Nick, i will need to send 2 types of data on the net ...
1. the actual power that the PV system generate, for this i'll need the time between last 2 pulses every 5 minutes
2. the total generated power, and here i'll count all pulses of that day.


If that's what you truly want to do, look into msp430: their crystal oscillator is "instant on". on that.

Dhenry ... I allready have difficult to understand this world cause I'm newbe, thansk a lot but i don't want to go versus new mcu's

I want to ask something also.
In the link of Nick page http://www.gammon.com.au/forum/?id=11497 i so the difference from
SLEEP_MODE_PWR_SAVE: 1.62 mA - this I can use if I'll use the external Timer2 using the 32KHz cristal
SLEEP_MODE_PWR_DOWN : 0.36 mA - for this mode I'll use the external RTC chip.
...so the diff is 1.26 mA
My question is... how much ampere an external RTC can use ? ...less than 1.26 I hope right ?

Thanks again all
Denis

dhenry

Quote
how much ampere an external RTC can use ?


Look into the device datasheet for that. Can be less than 1ua, depending on the rtc and mode you are  running it in.

Go Up