Practicum Report 1st Microcontroller System

PRACTICUM REPORT: 1ST MICROCONTROLLER SYSTEM INPUT OUTPUT APPLICATION SUBMITTED BY : Michael Kurniawan 2018123456 ELECTRICAL ENGINEERING DEPARTMENT UNIVERSITY OF CINCINNATI 2022 I. PURPOSE OF THE EXPERIMENT In this experiment, students are expected to be able to run input and output on the ATMega 16 menu. II. THEORY BASIS A brief explanation of each PIN on the AVR ATMega16 microcontroller is as follows: PORT A : PORT A functions as an analog input to the internal ADC on the ATMega 16 microcontroller. It also functions as an i/o PORT of 8 bit direction. If the ADC is not used each PIN provides an internal pull up resistor that can be activated for each bit. PORT B : PORT B functions as an i/o PORT of 8 bit direction each bit provides an internal pull up resistor that can be activated for each bit. PORT B also functions various alternatives. PORT C : PORT C functions as an i/o PORT of 8 bits each PIN provides an internal pull up resistor that can be activated for each bit. PORT c is also used as a JTAG interface. PORT D : PORT D functions as an i/o PORT of 8 bits each PIN provides an internal pull up resistor that can be activated for each bit. PORT D also has a variety of alternative functions Reset : A low-level reset on this PIN for more than the minimum specified length of time will cause a reset even if the clock is not executed. XTAL1: input to the inverting oscillator amplifier and internal clock circuit input XTAL2 : output from the inverting oscillator amplifier AVCC : is a power supply voltage input for PORT a as ADC is usually connected to vcc even though the dc water is not used if ADC is used should be connected to vcc through a low pass filter. AREF : is the reference voltage for ADC PORT : As a digital input or output ATMega 16 has 4 PORTs named PORTA, PORTB, PORTC, PORTD. the four PORTs are bidirectional lines with internal pull up options. Each PORT has three bit registers namely DDxn, PORTxn, PINxn. The letter x represents the letter name of the PORT while the letter n represents the bit number. The DDxn bit is contained in the DDrx i/o address, the PORTxn bit is contained in the PORTx i/o address and the PINxn bit is contained in the PINx i/o. The DDxn bit in the DDrx (Data Direction Register) register determines the direction of the pin. If DDxn is set 1 then Px functions as an output PIN. If DDxn is set 0 then Px functions as an input PIN. If PORTxn is set 1 then when the PIN is configured as an input PIN, the pull up resistor will be activated. To turn off the pull up resistor PORTxn must be set 0 or the pin is configured as an output PIN. The PORT PIN is tri state after the reset condition. if PORTxn is set 1 when the pin is configured as an output PIN then the PIN will be logic 1. And if PORTxn is set 0 when the pin is configured as an output PIN, the PIN will be logic 0. When changing the PORT condition from a three-state condition (DDx n = 0, PORTxn = 0) to an output high condition (DDxn = 1, PORTxn = 1) then there must be an intermediate condition whether it is a pull up enable condition d DDxn = 0, PORTxn = 1) or an output low condition (DDxn = 1 PORTxn = 0). Normally a pull up enabled condition is perfectly acceptable, high impedance does not notice the difference between a strong high driver and a pull up. If this is not a problem then the PUD bit in the SFIOR register can be set to 1 to turn off all pull ups in all PORTs. Switching from an input state with pull ups to an output low state also poses the same problem. We must use a tri state (DDxn = 0, PORTxn = 0) or an output high (DDxn = 1, PORTxn = 0) as the transition condition. Table 1. PORT pin configuration DDxn PORTxn PUD I/O Pull-Up Comment (In SFIOR) 0 0 X Input No Tri-State (HI-Z) 0 1 0 Input Yes Pulled low 0 1 1 Input No Tri-State (HI-Z) 1 0 X Output No Output Low 1 1 x Output No Output High Bit 2- PUD: pull up disable If the Bit is set to 1 then the pull up on the PORT i/o will be turned off even though the DDxn and PORTxn registers are configured to turn on (pull up) (DDxn = 0, PORTxn = 1). I/O Access To access the PORT on the avr microcontroller, you must recognize the registers on the i/o PORT. There are bit registers on the i/o PORT, namely DDrx, PORTx, and PIN x. The DDrx register is used to determine whether the PORT will be used as input or output, while the PORTx register is used to send data out of the PORT when DDrx is set as output. And the PINx register is used to read PORT data when DDrx is set as input. III. EXPERIMENTAL METHOD A. Tools and Materials 1. ATMEGA16 minimum system 2. USB ASP 3. Jumper cable 4. Project board 5. LED 6. 1k resistor 7. Push button 8. Microchip studio 9. Khazama B. Experiment Steps 1. Prepare the tools and materials and then the circuit on the project board as shown in Figure 1. Figure 1. Circuit of turning on 1 LED 2. Make a program according to the experiments conducted IV. RESULTS AND DISCUSSION Coding programming: #define F_CPU 8000000L #include #include int main (void ) { DDRC = (1<, includes the atmega input or output library 3. #include , includes the atmega delay library for input output PORTs 4. int main (void), the command that starts each language program code 5. DDRC = (1< #include #define Tombol PB4 #define Tombol_on bit_is_clear (PINB,Tombol) int main (void ) { DDRC = (1<, input or output library from atmega16 3. #include , includes the atmega16 delay library for PORT i/o 4. #define PB4 Button, defines that the push button button to be used on PORTB4 5. #define Button_on bit_is_clear (PINB, Button), defines that when the push button button is on when it is logic value 0 6. int main (void), the command that starts every language program code 7. DDRC = (1<