Last Updated: Jan 11, 2013

This is a short note on programming the Atmel ATtiny85 with the Sparkfun Pocket AVR Programmer. There are 2 parts to this note – please read the one relevant to you.

1. Programming ATtiny85 on windows using Atmel Studio 6 and WinAVR.
2. Programming ATtiny85 on Mac OS X using Crosspack.

1. Programming ATtiny85 on windows using Atmel Studio 6 and WinAVR.

First, jump through the necessary hoops to install the driver for the programmer (USBTiny). You can read instructions here:

http://newbiehack.com/MicrocontrollerProgramTransferPart2Drivers.aspx

Then, you need to download Atmel Studio 6:

http://www.atmel.in/tools/atmelstudio.aspx

Next, install WinAVR:

http://sourceforge.net/projects/winavr/files/

Now, watch this video by newbiehack.com on Atmel Studio 6 setup:

http://www.youtube.com/watch?v=iTTZUpzAjKc

The video backtracks a lot due to some path errors, and even at the end, it is not clear what was entered in the text boxes. So here is the relevant dialog:

The problem is that Atmel Studio 6 ignores the “Initial Directory” box, and the hex file path specification is tricky. So here it is – notice the “:i” at the end:

-c usbtiny -p attiny85 -U flash:w:”$(ProjectDir)\Release\$(ItemFileName).hex”:i

That’s it. Once you have these set up, you have a fantastic tool for AVR development. Code, debug, and upload to your chip right from Atmel Studio 6. I am switching to windows for AVR development, since there is no such professional tool on the Mac.

2. Programming ATtiny85 on Mac OS X using Crosspack.

First you need to install CrossPack for AVR development:

http://www.obdev.at/products/crosspack/index.html

You don’t need Xcode, and the above comes with everything you need, including avrdude.

After installation, you will find a “CrossPack-AVR-Manual” link in the Application folder, which you should go through.

Here is how you can create simple LED blinking application.

In a Terminal window:

$ avr-project hello
Using template: /usr/local/CrossPack-AVR-20121207/etc/templates/TemplateProject
$ cd hello
$ ls
firmware    hello.xcodeproj
$ cd firmware/
$ ls
Makefile    main.c

Now, you need to modify the Makefile as follows: (diff below)

20c20,21
< DEVICE     = atmega8
---
> #DEVICE     = atmega8
> DEVICE      = attiny85
22c23
< PROGRAMMER = #-c stk500v2 -P avrdoper
---
> PROGRAMMER = -c usbtiny #-c stk500v2 -P avrdoper
24c25,27
< FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
---
> #FUSES      = -U hfuse:w:0xd9:m -U lfuse:w:0x24:m
> # for ATTiny85
> FUSES       = -U lfuse:w:0x62:m -U hfuse:w:0xdf:m -U efuse:w:0xff:m 

I got the information for fuse from the website below:

http://www.engbedded.com/fusecalc/

Here is a simple program from denhart.dk which I modified a bit:

http://denhart.dk/2011/08/programming-attiny85-with-avrdude/

 C | 
 copy code |
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#include <avr/io.h>
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#include <util/delay.h>
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int main (void)
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{
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  //Set PORTB.3 to be output
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    DDRB = 0b00001000;
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  while (1) {
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    //Set PORTB.3 high
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    PORTB = 0b00001000;
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    _delay_ms(500);
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    //Set PORTB.3 low again
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    PORTB = 0b00000000;
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    _delay_ms(100);
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  }
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  return 1;
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}

Now for the connections.

Here is the pinout for ATtiny 85 from the Atmel datasheet:

And here is the connection diagram for the 3×2 header of the Sparkfun pocket programmer.

Now, hook up the circuit, put an LED between pin 2 (PB3) and pin 4 (GND), plug in the programmer to the USB port and type :

$make install

If all goes well, you will see the LED blinking.

In India, you can buy the Sparkfun Pocket AVR Programmer from Rhydolaz, Kochi (albeit at an inflated price).