thebends.org/~allen/avr

AVR

This page is a summary of what I have found while programming AVR devices, with a particular focus on OS X based development, since finding OS X specific resources can sometimes be difficult. It helps to have a decent unix and C background to fill in some of the gaps in documentation.

Hardware

See photos of my AVR Hardware in my picasaweb album.

ATSTK500

The ATSTK500 is a great starter kit. If you are running windows, it is pretty easy to get started using AVR Studio. Under OS X, avr-gcc, avr-libc, and avrdude are helpful. For avrdude, I had to use the "stk500v2" programmer type since my STK500 has firmware version 2.

Overall this is a great board because it comes with LEDs and Switches built in which are very helpful for writing simple programs or debugging.

Easy Ethernet AVR

The Easy Ethernet AVR is a board that combines a Realtek RTL8019AS ethernet controller and an ATmega32. Also comes with onboard serial port and AVR ISP programming port. I don't have a standalone ISP programmer, but it can be connected to the 10 pin ISP slot on the STK500.

It looks like they currently have some good deals at nerdvilla on their Easy Ethernet/AVR kits, since wired isn't the range anymore. It looks like their stock of assembled parts is running low.

Keyspan USB High Speed Serial Adapter

The above boards come with serial programming interfaces, so in order to program them from a mac I use a USA-19HS usb to serial adapter.

Software

The essential software needed is avr-gcc, avr-libc, and avrdude. You may also find it useful to have uisp if you need to set any fuses. uisp currently doesn't support the STK500 version 2 firmware, so when I need to change fuses, I unfortunately need to boot to windows and run AVR Studio.

The avr-libc documentation has good step-by-step instructions for installing everything you need to do avr development on your mac. See Installing the GNU Tool Chain. Another (easier?) option is to use fink, but you must configure fink to use the unstable package tree.

Community

  • OSX-AVR
  • AVR Freaks
  • Programming an AVR microcontroller using OS X
  • SparkFun Projects

    Code

    Feel free to do whatever you want with this code, but please email me at allen [at] thebends [dot] org if you find it useful, or have any suggestions.

    Hello World

    This very basic example simply counts from 0 to 255, outputting the value on port C of the AVR. When using an STK 500, you can hook up the PORTC pins to the LED pins and have a nice little show.

    Serial Port Logging Library

    I found this logging library useful when developing and debugging other AVR applications. It support dumping single values as hex or entire buffers as hex bytes, or NULL terminated strings.

    Realtek RTL8019AS Driver

    The Easy Ethernet/AVR comes with a pretty good example driver written by Fred Eady (of EDTP Electornics). I've written a stripped down library based on his examples that will invoke your callback when a packet is received.

    Packet Sniffing

    packet_dump is a small program that combines the two libraries above, and logs incoming packets over serial.

    Here is some example output of packet_dump. NOTE: The mac addresses have been changed to proect the innocent. 

    [*] packet_dump initialized; waiting for packet
[*] packet received
[ ff ff ff ff ff ff 01 0c a5 ce 86 d6 08 00 45 00 00 54 17 f4 00 00 40 01 
: 4b 52 0a 00 01 65 0a 00 01 ff 08 00 79 a2 2a fa 00 00 46 87 14 30 00 04 
: 0d a5 08 09 0a 0b 0c 0d 0e 0f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 
: 1e 1f 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f 30 31 32 33 34 35 
: 36 37 85 b0 ff e8 ]
[*] end of packet
[*] packet received
[ ff ff ff ff ff ff 00 13 c3 cd a7 9a 08 06 00 01 08 00 06 04 00 01 00 19 
: e3 dc ab 9d 0a 00 01 04 00 00 00 00 00 00 0a 00 01 65 00 00 00 00 00 00 
: 00 00 00 00 00 00 00 00 00 00 00 00 92 0f 67 6b ]
[*] end of packet
[*] packet received
[ ff ff ff ff ff ff 01 0c a5 ce 86 d6 08 06 00 01 08 00 06 04 00 01 00 0d 
: 93 82 18 1d 0a 00 01 02 00 00 00 00 00 00 0a 00 01 65 00 00 00 00 00 00 
: 00 00 00 00 00 00 00 00 00 00 00 00 96 92 6c 8f ]
[*] end of packet