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Problem: GPIO debounce not working
#7
(06-29-2019, 09:12 AM)Jewa_TWN Wrote:
(06-25-2019, 08:19 AM)Jewa_TWN Wrote:
(06-24-2019, 01:20 PM)Tim Curtis Wrote: I don't disagree however I'm not the dev responsible for the GPIO class library used in moOde's GPIO Buttons module. You would need to contact the maintainer of RPi.GPIO https://pypi.org/project/RPi.GPIO/

The script used in moOde is located in the directory below
/var/www/command/gpio-buttons.py

-Tim
Tnx,

Send the request / feedback to the maintainer of the RPI.GPIO
Once I got feedback, I will post it here.

For the meantime to "solve" my issue, i will invert the signal:
I will use a N-FET to have the GPIO at 0V (solid!!) when the supply is ok.
(The FET will five me a few milli-ohm connection, iso a 2K pull up)


This should reduce the EMI influence. Its not good, but should work.
Most likely after the weekend.

Regards,
Jeroen

=================================
Update after the above:

NO reply from the GPIO maintainer yet :Cry a pity..  

Hardware changes:
Added a extra FET, to invert the signal:
The solid N-FET  + 330nF cap between Drain & 0V (0V when supply OK, 3V3 when about to shutdown) helps, but sensitivity is still there for touching the enclosure.
(Due to ESD discharge, as im walking on slippers indoor :-))

Next option is to solder a cap directly on the PI, not really preferred..

Keep you posted.
J

Slightly modified the PI...

Added a 1uF (0603 size) capacitor & 1K resistor between GND & the GPIO pin, directly on the board.
The 0603 nicely fits between the pins, & utilizes the GND pin/plane beside it. Cant get any shorter on the board Big Grin 
Next, a 680-Ohm (trough hole!!) resistor to connect to the "UPS mode" signal.
A SMD resistor will not hold with a wire.


Reason to use 1K & 680 Ohm network, is that in this way I can use 5V signals. (gives 3V on GPIO, when 5V is applied)
Second, it has a pretty low impedance.

Pictures attached, for those who want to try as well.

Will try this modification for a while, then post if it works.

Regards,
J

   
   
   
   
   
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Messages In This Thread
GPIO debounce not working - by Jewa_TWN - 06-23-2019, 07:16 AM
RE: GPIO debounce not working - by Tim Curtis - 06-23-2019, 12:55 PM
RE: GPIO debounce not working - by Jewa_TWN - 06-24-2019, 07:12 AM
RE: GPIO debounce not working - by Tim Curtis - 06-24-2019, 01:20 PM
RE: GPIO debounce not working - by Jewa_TWN - 06-25-2019, 08:19 AM
RE: GPIO debounce not working - by Jewa_TWN - 06-29-2019, 09:12 AM
RE: GPIO debounce not working - by Jewa_TWN - 07-20-2019, 09:39 AM

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