AVR DMX-512 DONGLE FOR PC's

EASY to build readily desingned PCB or proto board
CHEAP, no expensive parts
SEND and RECEIVE DMX SIMULTANEOUSLY
255 output channels
127 input channels
Connects to computer parallel port
EASY implementation to control software
POSSIBLE to load default boot up scene to dongle

DISCLAIMER!!
I don't take any responsibilty if YOU destroy your PC or any data loss or anything!!!
This desing is NOT FREEWARE, it can used freely personal and educational use.
All copyrights are reserved by Kari Viitala

Introduction

AVR DMX-512 dongle is simple interface between DMX-512 equipments and personal computer. Dongle is connected to computer parallel port. Dongle can transmitt 256 channels and receive 128 channels dmx data simultaneously. Received dmx data can merged to incoming computer data (highest takes precense) and data can be read to computer. DMX data transmitter and receiver works even if computer locks up, also it is possible to load dongle internal memory default boot up scene. Default scene is transmitted after dongle has been powered up.

Hardware

AVR DMX-512 dongle uses Atmel AT90S8515 AVR microcontroller as a DMX engine. It has 8k code memory and 512 bytes SRAM and EEPROM. Controller is in circuit programable, it means that programming can be done when controller has been attached to the board. Suitable programmer is for example STK200 which is supplied with AVR development kit or it can be also bought from Kanda Systems also any other programmer can be used. Connections to DMX-512 buses is done using "industry standard" RS-485 transceiver circuit SN75176B. Connection to PC's parallel port is done 25pin D-connector. There are current limiting resistors between microcontroller and parallel port to protect overcurrents.

Software

Software to dongle is written using C. I used Imagecraft AVR C-compiler. Fully working time limited demo version of their compiler can be downloaded their web site. You don't need to compile code if you don't want, I have attached compiled code to the packet. Description about communication protocoll between PC and dongle can be found from downloaded package.

I have also made test program for the dongle. Using test program you can set channel values and view incoming dmx data. Test program is written in Visual Basic 5.

Last words....

If you make application software for my dongle or you need source code for the dongle, please let me know and don't hesitate to contact me if you have comments or suggestions about desing.

VIEW SCHEMATICS (jpg, 110kB)

VIEW AVRDMX DONGLE

DOWNLOAD AVR DONGLE INFORMATION
Includes: Schematics,PCB,BOM,compiled code and manual
(sourcecode can be obtained from me by email)
AVRDMX1.ZIP (updated: 6 june 2000)

DOWNLOAD AVR DONGLE TEST PROGRAM
DMXTEST.ZIP (2.3MB)