Dear Sir/Madam,
I have a Robot Arm with ADC input pin for external control but I don't have any specification information on hands. I only know the Robot Arm can be communication with the Arduino board without a problem.
I want to have a simple circuit to provide a 3.3V input to the ADC input pin. There are two circuits. May I know which one is a good practice if I don't want to waste any resource?
Circuit A: Directly connect a switch between a power source and the ADC input pin.
Circuit B: Adding a pull-up resistor to build the circuit and connect to the ADC input pin.
I only know the Arduino board can only provide 3.3V output to the Robot arm as an input voltage.
I heard some experienced engineer that many microcontrollers have internal pull-up resistor, hence an external resistor may be a waste of resources.
Other engineer says that directly connect to 3.3V is too dangerous as we don't know how much current will be flown into the microcontroller and too much current will damage the Robot Arm.
May I know which engineer's suggestion is correct? Could you help to select with explanation?
Best regards,
Kelvin.
I have a Robot Arm with ADC input pin for external control but I don't have any specification information on hands. I only know the Robot Arm can be communication with the Arduino board without a problem.
I want to have a simple circuit to provide a 3.3V input to the ADC input pin. There are two circuits. May I know which one is a good practice if I don't want to waste any resource?
Circuit A: Directly connect a switch between a power source and the ADC input pin.
Circuit B: Adding a pull-up resistor to build the circuit and connect to the ADC input pin.
I only know the Arduino board can only provide 3.3V output to the Robot arm as an input voltage.
I heard some experienced engineer that many microcontrollers have internal pull-up resistor, hence an external resistor may be a waste of resources.
Other engineer says that directly connect to 3.3V is too dangerous as we don't know how much current will be flown into the microcontroller and too much current will damage the Robot Arm.
May I know which engineer's suggestion is correct? Could you help to select with explanation?
Best regards,
Kelvin.