I have a question regarding my MOD-WIFI-ESP8266-DEV board and its schematic. Should not be board specific, but more of general understanding of pull-up & pull-down mechanics...
Is this guy on the Olimex forum right by telling that you can simply pull such an "pulled-up" pin to GND?
Question regarding Pull-up & Pull-down Resistors
Re: Question regarding Pull-up & Pull-down Resistors
That will probably work.
It all boils down to how much current the pin can sink. But my guess is that with 2K ohms, it should be able to override that. I assume that you're talking about the SCL line?
V= IR, or I = V/R. You want the voltage to below the half way mark, so if the voltage across the resistor is more than 1.65v then the signal will look like a logic low. So any current > 1.65/2000 = 0.825 mA should look like a logic low.
It all boils down to how much current the pin can sink. But my guess is that with 2K ohms, it should be able to override that. I assume that you're talking about the SCL line?
V= IR, or I = V/R. You want the voltage to below the half way mark, so if the voltage across the resistor is more than 1.65v then the signal will look like a logic low. So any current > 1.65/2000 = 0.825 mA should look like a logic low.
Re: Question regarding Pull-up & Pull-down Resistors
Makes sense. Thanks a lot!