ATmega324

Hello everyone,

Sorry if this has been covered before but after googling not much info came up. Am finding that i don’t have enough pins with the Arduino UNO but the Arduino MEGA is far to many so is it possible to use the ATmega324 in the same way i use the Arduino UNO with the Arduino IDE?

Thank you.

If you write your own Arduino core for it you can use it like an Arduino but generally it's best to stick with genuine Arduino hardware.

There are a number of tricks for extending the number of output and input pins. You can use three pins to control a shift register to add outputs or inputs in groups of 8. It would almost certainly be easier to do that then to re-write the Arduino core libraries to support a new processor.

'324 is just a '1284 with less memory.
With not too much fuss should be able to mimic maniacbug's '1284 files with the '164/'324'/'644 (and A, P etc) specifics.

  • add a '324 section to avrdude.conf if not there already with signature bytes, memory size changes
  • add a '324 section to boards.txt with avrdude.conf name call out, memory size change
  • reference the '1284 bootloader and whatever pinout_h file you want to use

Pavilion1984:
Hello everyone,

Sorry if this has been covered before but after googling not much info came up. Am finding that i don't have enough pins with the Arduino UNO but the Arduino MEGA is far to many so is it possible to use the ATmega324 in the same way i use the Arduino UNO with the Arduino IDE?

I typed "arduino ATmega324" into google and the first link was this: Arduino Forum

OTOH you don't really gain an awful lot for what you're giving up. You're not getting any extra RAM or flash memory and you'll gain more output pins (for example) by adding a 16-bit shift register to a '328 than moving to a '324.

Bump up to a '1284 tho and you’ll have access to the most SRAM of any arduino - 16KB.
'328 doesn’t give you 2 hardware UARTs. Or JTAG access. 32 IO without going to external hardware can be a benefit too - 16 bit shift register is only 1 direction, need a 2nd one to be bidirectional. Andwhat if you’re after a couple more analog inputs?
I can even sell you a board for $5 (mailed to US location) to build up into a duemilanove style board.
Populate as you see fit from your parts bin and with connectors to suit your project, with an onboard mikroe483 FTDI module ($11 at mouser.com) or plug in an offboard FDTI Basic type part for sketch downloading only.