Startup time

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Startup time

By Alex R
- Thu Nov 17, 2016 1:26 am #58237 Hello, after powering on node mcu board requires about 0.2s before init.lua starting,
lowest power consumption without RF is about 20mA, so if i need startup module every 20 seconds from deep sleep it takes 0.2/20*20 = 0.2mA average current for init only, it seems too much!
Are there any solution for faster start up, may be silent boot without serial debug printing?

My script requires about 0.001s every 20s, esp8266 requires 200 times more!
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Re: Startup time

By RichardS
- Thu Nov 17, 2016 12:58 pm #58263 20mA can be drawn from a 100mAh battery for 5hours, your 0.2s would allow 90,000 power ups... or at every 20 minutes, thats 30,000 minutes....

100mAh / 0.2mA is also 30,000 minutes

So yes your calcs are good, but overall this consumption will pale in comparison to once the WIFI is on and you connect and shutdown.... cause its going to be more 60mA average for the next 3-4 seconds...

There are many many people talking about this exact thing on this site, you should search for it....

RichardS
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Re: Startup time

By Alex R
- Fri Nov 18, 2016 3:36 am #58287 Hi!
30 000 minutes is only 21 days!
Without additional 0.2s startup device will stay alive much more (Radio module disabled)
my application checks the external sensor with disabled radio module (enabling only in an emergency)
For example (wake up every 20s for 1 year):
10uA deep sleep current * 1 year = 88 mAh battery capacity
1576800 startups * 0.001s (for checking sensor) * 20mA = 9 mAh battery capacity
1576800 startups * 0.2s (for printing debug info) * 20mA = 1752 mAh battery capacity

so i need 2000 mAh battery for 1 year insted of 100 mAh, it seems i need additional microcontroller :(
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Re: Startup time

By RichardS
- Fri Nov 18, 2016 8:26 am #58304 No surprise here, it was never meant to be battery operated.... typically WIFI devices do not fit this category as the WIFI system was never optimized like Bluetooth was from day one development.....

RichardS
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