8/20/2019 Atmel ATmega328 Test Circuit Diagram

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Atmel ATmega328 Test Circuit Diagram

The ATmega88 through ATmega328 microcontrollers are said by Atmel to be the upgrades from

the very popular ATmega8. They are pin compatible, but not functionally compatible. TheATmega328 has 32kB of flash, where the ATmega8 has 8kB. ther differences are in the timers,

additional !"A# and $$%"#, the addition of pin change interrupts, and a divide by 8

 prescaler for the system clock.

The schematic below shows the Atmel ATmega328 circuit as it was built on the test board. The power supply is common and is shared between all of the microcontrollers on the board. The

ATmega328 is in a minimal circuit. &t is using its internal 8 #'( ") oscillator *divided by 8+.

ith the ATmega328 & needed to both burn a bootloader and download Arduino sketches. The bootloader is programmed using the &!% programming connector, and the Arduino sketches are

uploaded via the -pin header. Be aware that programming the Arduino bootloader into the

ATmega88, ATmega/-8, or ATmega328 micrcontroller will change the clock fuses, re0uiring theaddition of an e1ternal crystal. The crystal shown on the schematic is only required  when the

ATmega328 is going to be used as an Arduino, although it may be desired in any real world

application. & typically run them at /- #'(, but they will run as high as 2 #'(.

There are schematics and an $1press%)B design file for a full 28pin A" development board that supports the ATmega8, ATmega48, ATmega88, ATmega/-8, and ATmega328 *the

ATmega328 pinout is the same as these others+.

Projects featuring the ATmega328

•!&") &" remote receiver 

• 28pin A" development board

Atmel ATmega328 Datasheet

'ere you can find the current Atmel ATmega328 datasheet 

Atmel ATmega328 Pinout

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Atmel ATmega328 %inout

Schematic Diagram

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Parts

• &)/ Atmel ATmega328 #)5

• )/ ./ u6 ceramic capacitor 

• )2,)3 22 p6 ceramic capacitor 

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• 7/ /- #'( crystal

• "/ /k 9 /:4 resistor 

• "2 33 9 /:4 resistor 

• ;$</ mm red ;$<

• !/ #omentary pushbutton switch

• !/ / pin shielded header or dual row header 

• =/ - pin #ole1 >>/ or single row header 

•  ?ot shown

o %erfboard

o 28pin socket

o %ower supply

Notes

• This board works with the ATmega8, ATmega48, ATmega88, ATmega/-8, and

ATmega328

• The ATmega8 is not code compatible with the others.

The schematic below is for a more comprehensive 28pin A" board that can be found

elsewhere on the site. &t has switches, ;$<s, pots, an &!% connector and a serial TT; uploadconnector. The upload connector is compatible with the 6T<& TT;232" cable as well. &t has

 been tested with ATmega88, ATmega/-8, and ATmega328 microcontrollers, but should work

with ATmega8 and ATmega48 as well, although the ATmega48 does not support bootloading.

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28pin ATmega #icrocontroller !chematic

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5ploading an Arduino sketch into an A"Boards <ev28A with an ATmega328

NOTE: The ATmega48, ATmega88, ATmega/-8, and ATmega328 specs can all be found in theATmega328 datasheet. The ATmega8, being a different part, has it@s own datasheet.