Programming the ATtiny85 From Raspberry Pi

Introduction: Programming the ATtiny85 From Raspberry Pi

These instructions tell you how to setup and program the ATtiny85 microcontroller from a Raspberry Pi via the SPI interface. Lots of people use the Ardiuno to do this (then you can use the Arduino IDE and simplified C commands), or you can use a USB based programmer. I do not have an Ardiuno and don't want to buy a dedicated programmer. I do have a Pi, so I was pleased to learn I could use it as a way to get into microcontroller programming.

You will need:
Raspiberry Pi
ATtiny85 chip
5 x 1K resistors (or similar)
LED of your choice
A connection to the GPIO of the Pi, and a breadboard and wire.

Based on

Step 1: Setup the Raspberry Pi

At the terminal of the Pi:

Download and build avrdude

sudo apt-get install bison automake autoconf flex git gcc
sudo apt-get install gcc-avr binutils-avr avr-libc
git clone
cd avrdude/avrdude
./bootstrap && ./configure && sudo make install

Setup SPI on the GPIO

sudo raspi-config
and Enable SPI device in the Advanced Options (see picture)
You can check this at the command line with lsmod, no need to reboot. (Maybe need to sudo modprobe spidev)

Download and build WiringPi for the gpio commands

cd ~
git clone git://
cd wiringPi

Step 2: Electrical Connections

Connect up the ATtiny85 to the Raspberry Pi GPIO (wire colours from the picture are given for reference):

GPIO pin ATtiny pin Comment
15            1                GPIO22 to Reset (through 1K, Blue wire)
17            8                3.3 V (Green wire)
19            5                MOSI (through 1K, Yellow wire)
21            6                MISO (through 1K, Orange wire)
23            7                SCLK (through 1K, Red wire)
25            4               GND (Brown wire)

(I could not find a way to do a nice table in instructables)

Step 3: Test Avrdude Connection

Test avrdude connection to the ATtiny85, we are set up with GPIO pin 22 on the ATtiny reset. We must pull this pin low to program the chip. This can be done in other ways, e.g. a switch, but I an using another pin of the GPIO to do this.

sudo gpio -g mode 22 out
sudo gpio -g write 22 0
sudo avrdude -p t85 -P /dev/spidev0.0 -c linuxspi -b 10000
sudo gpio -g write 22 1

This must give success type messages!

Step 4: Program the ATtiny85

Program the ATtiny85:

cd ~
mkdir ATtiny85
cd ATtiny85
mkdir blinky
cd blinky

create the blinky.c file and add the following code
nano blinky.c
#define F_CPU 1000000L
#include <avr/io.h>
#include <util/delay.h>

int main(void)
DDRB = 0xFF; // PORTB is output, all pins
PORTB = 0x00; // Make pins low to start

for (;;) {
PORTB ^= 0xFF; // invert all the pins
_delay_ms(100); // wait some time
return 0;

add this code to a Makefile file
nano Makefile
CFLAGS=-g -Os -Wall -mcall-prologues -mmcu=$(MCU)
all :
$(CC) $(CFLAGS) $(TARGET).c -o $(TARGET)
$(OBJ2HEX) -R .eeprom -O ihex $(TARGET) $(TARGET).hex
rm -f $(TARGET)

install : all
sudo gpio -g mode 22 out
sudo gpio -g write 22 0
sudo $(AVRDUDE) -p $(AVRDUDEMCU) -P /dev/spidev0.0 -c linuxspi -b 10000 -U flash:w:$(TARGET).hex
sudo gpio -g write 22 1
noreset : all
sudo $(AVRDUDE) -p $(AVRDUDEMCU) -P /dev/spidev0.0 -c linuxspi -b 10000 -U flash:w:$(TARGET).hex

fuse :
sudo gpio -g mode 22 out
sudo gpio -g write 22 0
sudo $(AVRDUDE) -p $(AVRDUDEMCU) -P /dev/spidev0.0 -c linuxspi -b 10000 -U lfuse:w:0x62:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m
sudo gpio -g write 22 1

clean :
rm -f *.hex *.obj *.o
(Sorry, the instructables text editor has destroyed all the tabs and spacing in the code above, the Makefile will not work without tabs in the correct place)

To compile type:
To compile and upload code to the ATtiny:
make install
To optionally send fuses:
make fuse

This program oscillates ALL 5 pins as outputs so the LED should flash.
We are programming the ATtiny directly using avr-libc.
To change the setup of the ATtiny get fuses from :

9 People Made This Project!


  • Creative Misuse Contest

    Creative Misuse Contest
  • Fix It! Contest

    Fix It! Contest
  • Tiny Home Contest

    Tiny Home Contest

31 Discussions

I am lost when it comes to coding... Where should the TABS go? Can someone please post a picture of the correct code?

1 reply

Thankyou so much! I had purchased 10x ATtiny84a's and had no idea, until I stumbled upon this. Much Appreciated:)


2 years ago

Hi, this helped me to get going, but you should update/change one thing.

After reading this post:
I noticed that the 'linuxspi' programmer by default uses the GPIO pin 25 for reset, so your reset wrapper script is not needed. Else, great work ;)


Thank you.

This is a fantastic tutorial, and it really helped me get started. I'd like to point out a couple things I learned along the way, however. I don't know about at the time you were doing this project, but the "linuxgpio" configuration for avrdude exists in /etc/avrdude.conf on the RPi (after you install avrdude, of course); you simply uncomment the lines and set the pins to what they should be. Second, because the AVR and the RPi both run at 3.3v, I didn't find any need to use resistors for anything other than the LED itself, and that was only to protect the LED. And finally, if you hook the LED's positive pole to one of the SPI pins, the LED will happily blink for you as the RPi uploads data, which is cool and gives some nice feedback!

1 reply

Oh, and I used this with an ATmega88; I'm sure you can use it with any ATmega that supports 3.3v operation, which, for all I know, is all of them.

Works with atmega8. When I poweroff the Raspberry Pi the Reset pin GPIO 22 gets to zero, stopping the program on the microcontroller. I added a pullup resistor of 10 k to 3.3 v to GPIO22 and now it works after Pi poweroff too :) . Thank you. I made it but I don't yet have a camera / photo capable phone so no images...


3 years ago

Is it possible to program Atmega8-8PU using this?

Thank you! Thank you! Thank you! My L.E.D.s are flashing, and my stepper motor is spinning. I could not have gotten this far this fast without your VERY helpful Instructable!

i dont know nothing about makefile, could you help me, which is the path where the file should be, i have to paste or create a new file ?

hi im having this error"28:*** target pattern contains no '%' .Stop

Can anyone help me with this....

On the strength of getting blinky to work following this instructable (thanks for that), I thought I'd use what I'd learnt to install Atmel's TWI Bootloader on a ATTiny85 (Atmels Application Note: AVR112).

Unfortunately I fell at the first hurdle running the 'make' with error

'fatal error: ioavr.h: No such file or directory'

Has anyone done this successfully? If so, some pointers on getting passed this would be much appreciated.

1 reply

Problem solved by replacing lines:

#include <ioavr.h>
#include <inavr.h>


#include <avr/io.h>

Running the 'make' again gives error message:

Common_Define.h:164:1: error: unknown type name ‘__no_init’

Line 164 in Common_Define.h is:

__no_init uint8_t pageBuffer[PAGE_SIZE];

Can anyone throw some light on why code from Atmel doesn't seem to work?


That code uses the Arduino code libraries ("digitalWrite" etc.). You can program these devices that way but I do not cover it here.

I am using the avr-libc library. By the way this gives you the possibility to have three pwm outputs from the ATtiny85. I have mood light code I have used in the past, it's here:

I hope you can work out from the comments what the circuit should be like.



Thanks for the help i understand why it doesn't work now.
I gonna try to directly upload the hex generate by arduino and if it doesn't work i gonna use your code to make mine.

Thanks again

Hello and Thank you for your Tutorial.

But i have a few problems.

When i run make install it flashes ok, but i receive failure:

"avrdude verification error content mismatch"

and "avrdude safe mode lfuse changed"

What i doing wrong ?

I am trying to programm attiny45

Hello and thank you for tutorial.

But i have a problem. I would like to program Attiny45 and when i run make install ist says :

avrdude verification error content mismatch

avrdude safe mode louse changed, was 62 and now is 0

and when i set y to change fuse back then it freeze ...

Could you please help me