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Posted: Fri Feb 13, 2015 5:05 pm
Posted: Fri Feb 13, 2015 5:07 pmPosted: Fri Feb 13, 2015 8:47 pmlethe wrote:Markus Gritsch wrote:BTW, my intention of using pull-down is to be able to connect a switch to GPIO0 or GPIO2 of an ESP-01 board.
I don't get your need for a pulldown here. Just connect a resistor from VCC to the GPIO and a button from the GPIO to GND.
Posted: Sat Feb 14, 2015 3:00 amlethe wrote:I don't get your need for a pulldown here. Just connect a resistor from VCC to the GPIO and a button from the GPIO to GND.In your scenario, the external resistor isn't even needed: The same could be achieved with the internal pull-up. The problem with this configuration is, that if the switch is closed and a power cycle happens, the ESP is starting up in flash-mode, and not executing the user code anymore. Not very reliable.
lethe wrote:What's the issue with having it read 1 in open state?As said, the problem is pulling the GPIO to 0 in closed state during power up.