Using Atmega32 With Arduino IDE




Introduction: Using Atmega32 With Arduino IDE

Over time I have used all kinds of Atmel microcontrollers in various projects.

One of the most suitable was ATmega32. I have a small collection of development boards for Atmega32/16, some bought as-is, some made on stripboard.

Although the original Arduino boards offers a pleasant experience and a rapid development of the projects, when it was necessary to "extract" these projects to give them final shape I hit the well-known problem: arduino board must be "locked" in the project.

It is not only the price. Although a microcontroller in thru-hole package is significantly bigger than SMD version, it is still much smaller than an Arduino board.

And still I want to use the Arduino IDE to benefit from the collection of (very well made) (ready-to-use) libraries.

So I gathered together information useful for this purpose.

Step 1: Things You Will Need:

  1. Atmega32 microcontroller. :)
  2. Programmer (any programmer recognized by Arduino IDE). I use the USBasp programmer.
  3. Minimal setup for power-up Atmega32 microcontroller (breadboard, stribpoard or a classical development board).

We do not need all, photos above are for exemplification only.

Step 2: Software Set-up

  1. Download zip file attached to this instructables.
  2. Locate file boards.txt in arduino folder ...arduino-1.5.2\hardware\arduino\avr\boards.txt
  3. Append information from zip archive boards.txt to original boards.txt
  4. Make a folder named mega32 in ...arduino-1.5.2\hardware\arduino\avr\variants
  5. Copy file pins_arduino.h from the zip into folder created at step 4.
  6. Start Arduino IDE and select board.
  7. Select programmer

Later edit:

I removed link to github projet where I originally found. As long as there source changed and not fit this instructable.

After a message from the author: Eric Conner, I put back link to github project where I originally found this library:

Note: Zip file attached to this article is an older version of above library. This will work as this instructable was written.

Over time, after some feedback I noticed that source from github has changed.

Also, in comments you will see references to some errors, and how to to correct it.

This article and answers from comments is relate to version attached here, not github (newer) version.

Step 3: Done.

It's done.

Now you can try some simple examples that are already in Arduino.

Be very careful about correlation between ARDUINO pin and microcontroller pin.

Here is blink example: Files->Examples->Basics->Blink

Pin13 Arduino == Pin19 (PD5) Atmega32

  Turns on an LED on for one second, then off for one second, repeatedly.
  This example code is in the public domain.
// Pin 13 has an LED connected on most Arduino boards.
// give it a name:
int led = 13;

// the setup routine runs once when you press reset:
void setup() {                
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);     

// the loop routine runs over and over again forever:
void loop() {
  digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);               // wait for a second
  digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);               // wait for a second

After some comments I found two errors in the file pins_arduino.h

So I’ll post here the errors and correct values.

erroneous definition of SCL and SDA

const static uint8_t SDA = 8; //wrong
const static uint8_t SCL = 9; //wrong

must be changed in:

const static uint8_t SDA = 17; //correct
const static uint8_t SCL = 16; //correct

Since I am not the author of the project on github, it is subject to change beyond my control.

So please use code attached to this instructable and make above modifications.


For Serial library to work properly must be made following changes to the file HardwareSerial.cpp
In ...\arduino-1.5.8\hardware\arduino\avr\cores\arduino\HardwareSerial.cpp

will replace:

#if defined(__AVR_ATmega8__)
	config |= 0x80; // select UCSRC register (shared with UBRRH) 


#if defined(__AVR_ATmega8__) || defined(__AVR_ATmega32__) || defined(__AVR_ATmega16__)
	config |= 0x80; // select UCSRC register (shared with UBRRH) 

See also:



  • Water Contest

    Water Contest
  • Fix It! Contest

    Fix It! Contest
  • Tiny Home Contest

    Tiny Home Contest

124 Discussions


2 years ago


I'm having a problem with pin interrupts using this set-up

I can get INT0 and INT0 to work correctly, enabling the internal pull-up resistors and then using:

attachInterrupt(digitalPinToInterrupt(10), footOne, CHANGE); // Foot One - Pin 10

attachInterrupt(digitalPinToInterrupt(11), footTwo, CHANGE); // Foot Two - Pin 11

but if i try the same for INT2:

attachInterrupt(digitalPinToInterrupt(2), footThree, CHANGE); // Foot Three - Pin 02,

I the interrupt never gets triggered, despite each pin being set up in the same way with the same debouncing circuit.

Any ideas how to get INT2 to work correctly?


7 replies

Hello TomO26,

INT2 only works with RISING and FALLING. CHANGE only works for INT0 and INT1 on ATmega32.

There is no quick solution to this ... I just did some tests...

It seems that the problem is in arduino core files WInterrupts.c and wiring_private.h, there should be added support for ATmega32/16, but I can't do that in so little time.

Anyway It's interesting "bug"... I never feel need to use INT2 until now... When I needed more external interrupts I moved to ATmega1284 and i use PCINT...

I think there are some modified cores ... but i don't now what are their limits.. try to study "Sanguino", "Bobuino", "Mighty-1284P", I know about them, but I never study in detail...

I try to not modify too much default core files... to be easy to remake when arduino cores are upgraded... so I look inside WInterrupts.c and wiring_private.h but I can't see a quick solution...

Hi Silvus, Thanks so much for getting back to me!

For the particular application I managed to find a work-around:

(used the same interrupt pin for 2 of the switches, and send the output of one of the switches to a different digital pin, so that during the interrupt, the digital pin can be read and the correct switch chosen)

But next time if i need lots of interrupts I'll switch to a different chip! (my choice of the 32 was fairly arbitrary in this case as I'm new to micro controllers, all I knew was i needed more pins that the 328p)

a quick and dirty solution to use INT2:

put this in setup()

MCUCR |= (1 << ISC2);
GICR |= (1 << INT2);

and make a function exactly like this:

// code for int2 ....

you can put this function before.. or after main function (I tested with function after main()... )

so you can write something like this:

// code for int2 ....

I tested right now and work ...

Thanks again for your help.

I've been coming across an other issue, digital pins 18 19 20 & 21 aren't working properly.
I can't even get them to blink an LED

if i use the basic arduino example blink: it works correctly for the digital pins such as 15 16 17 22 & 23, but if I chance the pin in the program and on the breadboard, nothing happens. any ideas?


const int LED = 18;

// the setup function runs once when you press reset or power the board

void setup() {

// initialize digital pin as an output.

pinMode(LED, OUTPUT);


// the loop function runs over and over again forever

void loop() {

digitalWrite(LED, HIGH); // turn the LED on (HIGH is the voltage level)

delay(1000); // wait for a second

digitalWrite(LED, LOW); // turn the LED off by making the voltage LOW

delay(1000); // wait for a second


those pins have dual function I/O and JTAG. you must disable JTAG...

or by setting fusebits or by program... see this for more info:

for begining you can put this in setup function:

MCUCSR = (1<<JTD);
MCUCSR = (1<<JTD);

twice is not a mistake ...

Have fun!

Thanks! That's worked perfectly! hopefully I won't need to ask any questions as I've got all my inputs and outputs working!



ADC is not working on hardware but its works on proteus (software simulation).

i use USB-asp for uploading hex

Hello together,

i've encountered a problem. I've tried to read the ADC via "analogRead(A0)" for example. And the compiler responded with the error "'A4' was not declared in this scope".

also the function #define doesn't accept the argument A0 up to A7; does anybody else have expierenced this problem?

I also tried to read the value by using its digital Pin Number, but there is for example ADC5 = D26, but i need to insert "analogRead(27)" to get the corresponding value for ADC5;

thanks if you could help me with my problem here

1 reply
analogRead(0); //-> physical pin 40 (ADC0)
analogRead(1); //-> physical pin 39 (ADC1)
analogRead(7); //-> physical pin 33 (ADC7)

Pins A0-A7 are not defined. These definitions make sense for standard Arduino boards, where these pins are labeled on the PCB.

For this approach, I think is more intuitive as shown above.



LiquidCrystal lcd (5, 4, 3, 2, 1, 0);

const int ldrPin = A0;

void setup() {

lcd.begin(16, 2);

pinMode(ldrPin, INPUT);


void loop() {

int ldrStatus = analogRead(ldrPin);

if (ldrStatus <=300) {

lcd.setCursor (0, 0);

lcd.print ("XX");


else {

lcd.setCursor (0, 1);

lcd.print ("YY");



Hello Silvius,

I uploaded a simple blink sketch using arduino as ISP to blink an LED at PD7 with a delay of 250 ms. But the delay seems too long, about 4000 ms, which is 16x the amount I needed. Is there any problem with timing? How to solve it?

1 reply

Put some fusebits according with your osc... here are my fuse bits... read from working atmega32 with 16MHz quartz and USBASP. Working in Arduino IDE and AVR Studio:
low fuse :DE
high fuse: D9

hi Silvius

how to boot loader atmega32a with Arduino mega2560 board ?

hi Silvius!!

i m getting error of missing 'upload.tool'
configuration parameter, when uploading the code to Atmega 32 using
usbasp as programmer...plz help me in resolving the problem.

error while burning bootloader: missing 'bootloader.tool' configuration parameter

i am getting these error while i am trying to put bootloader in atmega32 and i am using usbasp as programmer, plz help me whr i am doing mistake

1 reply

There are no bootloader in this setup. Just use USBASP to upload your code.

Hello Silvius, Great Job man, i follow your step and first Toggle all pins of my atmega32 and it work,then after i use i2c protocol for data read write it also work but when i try to use SPI protocol MOSI and slave select pin are toggle and SCK pin of SPI not toggle it continue high no change in that pin ,can you please provide some information on SPI or give example code so it's help me. Thank you.