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Which register is used to define a pin as input or output in AVR microcontroller?
This register is used to configure the PORT pins as Input or Output. Writing 1’s to DDRx will make the corresponding PORTx pins as output. Similarly writing 0’s to DDRx will make the corresponding PORTx pins as Input….GPIO Registers.
| Register | Description |
|---|---|
| PINx | Used to Read the data from the port pins |
What is the difference between PIN and port in AVR?
PORT is used for enabling/ disabling the internal pull-up resistor in case of input pin and it is also used for setting the pin as HIGH/ LOW in case of output pin.
Why do we connect a capacitor between the VREF and the GND pin?
Explanation: A capacitor is connected between the Vref and the Gnd pin in order to stabilize the Vref value and also to increase the precision of the ADc converter. Explanation: The output of a DAC0808 is in the form of a current.
What are the digital input and output pins on AVR?
AVR® 8-bit microcontrollers control applications through their digital Input and Output (I/O) pins. These pins can monitor any voltage present as a high impedance input and supply or sink current as a high or low voltage digital output. These pins are usually organized in groups of eight and referred to as a port.
How to access input / output ports in Atmel AVR?
2.1 Blink LED on PB0 at a rate of 1Hz. 2.2 Blink LEDs on PB with different patterns according to given input. NOTE : I will frequently refer to ‘configuring pin’ or simply ‘pin’. Remember, a port has multiple pins. Thus in order to change setting for one port, you have to change setting for all port pins of that port.
What happens when PORTx is disable on AVR?
When the PORTx register disables the pull-up resistor the input will be tri-stated, leaving the pin left floating. When left in this state, even a small static charge present on surrounding objects can change the logic state of the pin. If you try to read the corresponding bit in the pin register, its state cannot be predicted.
Why are floating inputs not allowed on AVR?
Floating inputs should be avoided to reduce current consumption in all other modes where the digital inputs are enabled (Reset, Active Mode and Idle Mode). The simplest method to ensure a defined level of an unused pin is to enable the internal pull-up.