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Topic: Pinout of 328 chip (Read 1 time) previous topic - next topic

jonisonvespaa

May 01, 2012, 05:55 pm Last Edit: May 01, 2012, 06:10 pm by jonisonvespa Reason: 1
hi
im learning to lay out a pcb and want to put the atmega328 chip into it, i really just want to be double sure on the pin out of the chip, as ive got it layed out on my board

pin8 +5
pin 9 crystal + cap
pin 10 crystal +cap
pin 20 +5
pin 22 Gnd

pin 21 is this pin i wasnt too sure about is it +5?, i see from some guides connect +5 to it - AREF, what does this pin do?

ok i see its the analog ref pin for max input range 5v.
thank you

Krodal

Did you make a schematic? If you upload it, it will be a lot easier for us to see if it's okay.

MarkT

Nope, that pinout is definitely wrong, pin 8 is GND, pin 7 is +5V
[ I won't respond to messages, use the forum please ]

Jack Christensen

I always make sure I've had a look at the datasheet before I commit anything to a PC board.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

MarkT

Or use the Sparkfun library if using Eagle?
[ I won't respond to messages, use the forum please ]

When I use a bare ATmega328 on a breadboard I use this drawing to see the pins:
http://www.hobbytronics.co.uk/arduino-atmega328-pinout
Very handy because it has the Atmel and Arduino pin numbers on it.
www.bajdi.com

CrossRoads

Or copy an arduino schematic as a starting point, delete the parts you don't need.

http://arduino.cc/en/uploads/Main/Arduino_Uno_Rev3-schematic.pdf
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

jonisonvespaa

thanks very much for the help

Nick Gammon

Or this:



That has the pins, the minimal configuration, and the Arduino pin numbers in brackets.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

Tumbleweed

I really like Adafruit's stickers for breadboarded 328s, http://www.adafruit.com/products/554
When I am working on a prototyping board I will cut one in half lengthwise and reverse the sides to mirror the pins and stick them  on the bottom of the board.
Saves reversing everything in my head.
TomJ
Einstein once said you don't really understand anything until you can explain it to your Grandmother

CrossRoads

I think a few corrections are needed:

CTS on the FTDI connector needs to be grounded as well for the FTDI breakout board/cable.
(CP2102 modules don't need the CTS pin.)
Pin6 is DTR.

What's the 10K on the Tx line? That will kill any transmit drive capability.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

krazatchu

I've posted my eagle library here, which has a physical layout corresponding to the chip.
It might be useful: http://n0m1.com/2012/04/30/how-to-bread-board-arduino/
Michael
----------------------
http://www.krazatchu.ca

Nick Gammon


Pin6 is DTR.


I don't know how those ideas got into my head, but I found this once:

http://www.sparkfun.com/datasheets/DevTools/FTDI%20Cable%205V.pdf

That has pin 6 labelled as RTS.
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

MarkT



What's the 10K on the Tx line? That will kill any transmit drive capability.



Why would it do that?  Its to protect the pins and allow Arduino pin 0 to be used as an output.
[ I won't respond to messages, use the forum please ]

jonisonvespaa

#14
May 02, 2012, 04:29 pm Last Edit: May 02, 2012, 04:31 pm by jonisonvespa Reason: 1
here is my chip layed out whith what i think should be there could someone please verify it please.
thanks

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