Re: raduino_v1.08 released

Pavel Milanes Costa
 


El 27/04/17 a las 17:17, Steve Wright escribió:
On 28/04/17 08:59, Jack Purdum via Groups.Io wrote:
Would a Supercap have enough juice for a write? I have no clue.

it only needs a few milliseconds..

On 28/04/17 08:59, Jack Purdum via Groups.Io wrote:
Would a Supercap have enough juice for a write? I have no clue.

it only needs a few milliseconds..


That's no so simple, BTDT, or is it?

1 - You need to put a big capacitor (> 470uF in my case) on the +5v to the arduino.
2 - You need to decouple the +5v of the LCD backlight LED from the +5v of the Arduino: this is the power hog.
3 - You need to make a power divider from VCC mains to an analog input from the arduino and sense it aggressively for a fast dropping delta, then trigger the eeprom save. (digital pin read can also work, but looking for a dropping delta is faster)

I have done that for a friend... with a 820uF on the +5V for the arduino and this trick I can also see the banner:

  "POWER OFF"
"EEPROM SAVE"

On the LCD a few instants after complete power off... of course no backlight...

73 Pavel CO7WT.

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