As mentioned above, the official Arduino docs recommend a 10kΩ pull-down or pull-up resistor for digital input pins. On the ATmega microcontrollers (those on ... ... <看更多>

Feb 19, 2017 - Working Without a Pull-up/ Pull-down Resistor With Arduino: We can avoid using an external pull-up or pull-down resistors, simply by using ... ... <看更多>

A pullup or pulldown resistor is used to set an input to a pre-defined state. The button or switch is then used to override that pre-defined ... ... <看更多>

Internal pullups in ATmega are 10k, so if you connected a pin to GND through 1k resistor, you got a voltage divider, which would output 0.3V. My ... ... <看更多>

Re: your issue - I'm surprised that the Arduino's internal pullup resistors (which I believe are 20k Ω) didn't work for you, because I also used ... ... <看更多>