avr minimal circuit
The minimum system circuit of a microcontroller is a series of minimal so the microcontroller can work.
ATmegga AVR chip is equipped with an internal oscillator and thus no need external crystal for CPU clock source in order to save costs.
AVR microcontroller minimum system is very simple, just connect the VCC and AVCC to the DC +5V power supply voltage. Then GND and AGND with the ground. No need an additional crystal and reset pin is not connected to anything. With this circuit, AVR microcontroller has been able to work normally, but you can not reset the microcontroller manually. If you want to activate the reset pin with a button to trigger it, then connect the reset pin on your microcontroller with pull circuit made up of a 10k resistor and capacitor 10uF.
This circuit works for all AVR microcontroller family as ATMega8535, ATMega8, ATmega32, ATmega16 and others.
If you want to use larger crystals from 8MHz to your microcontroller circuit, then you can use an external crystal. You can see a more complete circuit on this page or this one.
ATMega8 Schematic Circuit (Minimum system) is a support circuit for the microcontroller.
Without this support circuit, the microcontroller will not be able to work.
Minimum system for microcontrollers consist of several components. The components are : crystal, capacitors, and the reset circuit (consisting of resistors and capacitors).
And the crystal must be combined by two capacitors. The capacity of this capacitor should be in accordance with the AVR ATMega8 datasheet.
RESET pin on AVR ATMega8 must be pull up with a 4K7 ohm resistor and stabilized with ‘100nF capacitors’.
You have to make the pin as a downloader port. pin of the downloader port must meet a standard sequence. The pin sequence is: MOSI, MISO, SCK, RESET, GROUND.
This AVR ATMega8 schematic is made with the EAGLE software.
This USBasp downloader can be used on the AVR microcontroller families such as ATMega8, ATmega16, ATMega8535, ATmega32, ATmega128 and much more. Based on Atmega8 (or can also be used ATMega88) and some additional components. USB connector as the interface with a computer and five pins as an interface with a microcontroller. The USBasp’s hardware is very easy to make. Once you finish making the hardware, you should fill the ATMega8’s memory with two firmware program that will be filled in eeprom microcontroller ATmega8. After that, USBasp downloader has been ready for use. To download the program, you must compile into .hex file using BASCOM AVR or CAVR. And you can transfer files with the .hex downloader software like avrdude, USBasp, khazama, PonyProg or other programs.
avr microcontroller BOARD schematics downloader
Arduino is a trademark that manufactures microcontroller development board. Arduino UNO is one type of development board produced by Arduino, and the new series is arduino uno R3.
Arduino UNO R3 is a computing platform that is very easy to use. Arduino UNO R3 is ATmega328P microcontroller based. According datasheet from ATmega328P, Arduino UNO R3 has a 14 pin digital input / output, and 6 of them can be used as PWM output pin. Arduino UNO R3 also has 6 analog inputs, has a 16MHz crystal, a USB port which can be used to download the program, a power jack, a reset button, and ICSP header.
how to optimized the arduino uno r3
Arduino features shown in the diagram above. Arduino UNO R3 provide + 5V, 3.3V and GND pin as a power source if needed by sensors or other devices. Users can also use the SDA and SCL pins on the pin number 27 and 28. Features ADC (Analog to Digital Converter) can be used on 23-28 pins. While the interrupt feature can be used on pin number 4 and 5 (pin number 4 is int0 and pin number 5 is int1). Serial communication (RX and TX) is provided on pin numbers 2 and 3.
arduino uno r3 layout diagram
Arduino Uno R3 design is very simple to facilitate the user in using it. On the left we will see an electric jack socket. Power jack is compatible to the power supply voltage 9-12V. In addition, we will see the USB port to communicate with a computer, either in downloading a program or data transfer via USB. As an indicator, arduino provides 4 LEDs. 1 for the power indicator, two LED indicators for serial communication (RX and TX), and 1 other LED connected at pin 13.
arduino uno r3 microcontroller pin mapping
The ATmega328 microcontroller datasheet shows the various features that can be used on the Arduino UNO R3.
arduino uno r3 board layout