JED Micro
Designers and manufacturers of audio/visual and industrial controllers in Australia

JED AVR200 Single Board Computer using the ATmega32 CPU


The $A90 AVR200 kit (plus GST), ($A185 built and tested, plus GST) is a low cost ATmega32 based board for industrial, educational and hobby applications.

This board features in two feature articles in Silicon Chip magazine: Part 1 & Part 2

Protected I/O is provided from all ports to screw terminals and it also provides a RTC, SPI, RS232, buffered I2C bus (and an RS485 option).

The kit featured in June/July 2005 Silicon Chip (Australia) magazine P84/91. It is all through-hole construction and easy to build without SMT hassles.

Availability: AVR200 kits and fully assembled boards are now shipping from JED.

An accurate voltage reference option and an RS485 option is available, and the "standard" build has 8 analogue inputs to Port A, 11 protected digital inputs (Ports B and D), and 9 FET outputs (Ports C and D).

A serial RS232 port is standard to a D9 connector, as is a buffered I2C port and a battery-backed RTC.


  • A precision reference for the analog port can be added to standard build boards;

  • Eight extra FETs can be added to Port A, replacing the eight analog inputs;

  • Four extra FETs can be added to Port B, replacing the four digital inputs;

  • Six output bits on Port C can become protected inputs, replacing the six FET outputs;

  • Three output bits on Port D can become protected inputs replacing the three FET outputs; and

  • An optional RS485 interface can be added, with a multiplexer for TX/RX switching between RS232 and RS485.

When ordering, please indicate whether you need the MegaLoad utility pre-loaded into the CPU you are ordering. If you do NOT, you have to use an AVRISP or a STK500 (see below).

All boards are supplied with a CD with all circuits, layouts, assembly instructions, test program, test instructions, and sample code which exercises all parts of the board, written in BASCOM Basic and CodeVision C. Setup instructions for programming systems (IDE) for BASCOM and CodeVision are included. Also is MegaLoad and a sample setup and Makefile for WINAVR, a PC environment, which allows use of the Gnu free toolkit for Gnu C.

Links above are to Atmel's data libraries.

AVR200 Schematic (colour)
AVR200 Schematic (B&W)
AVR200 Parts layout and connections
AVR200 Board technical description
AVR200 Board assembly instructions
AVR200 Software development options

AVR201 AVR201 32Kbyte to 256Kbyte FRAM memory board (piggyback) for data logging applications.

AVR202 Prototype board schematic and layout (for user hardware add-ons)


Available now ... a set of I2C expansion boards for the AVR200. Up to 16 device addresses, allowing up to 128 I/O bits can be addressed and controlled by the AVR200 (See Floribots below):

AVR212 input FET output board AVR212 Eight power FETs driven from
I2C bus. LEDs show status of all outputs. Layout/schematic PDF  Detail photo

AVR213 AVR213
Eight logic, switch or voltage inputs. LEDs show status of all inputs.
Layout/schematic PDF Channels can have pull-down resistors for voltage inputs, or can have pull-up inputs for switch or opto-isolators to ground (users can change pu/pdn mode). Detail photo.

Test system example ... how to build a test system with LOTS of I/O

The system shown in the photo below shows how to start with a plank of wood and build a end-of-line test system for testing manufactured cable/interconnect systems. The system uses an AVR200 CPU (far right) as the "brain" and a bank of four AVR212 FET output boards (red LEDs below) and eight AVR213 input boards (green LEDs below).

The program in the AVR200 drives a LOW onto each of the 32 inputs of the system under test in various combinations, and then the 64 inputs lines are read in by the AVR213s to the AVR200.

A 32-line table sets up the expected responses, and if an error occurs due to a short, open or swapped line, the expected results differ from the table. If it all agrees a  green LED lights. If an error occurs, a red LED flashes. This gives immediate results on a production bench test. Any faults are reported over the serial port to a PC, listing pin numbers and faults found. (The 10-way grey ribbon  I2C cable can be seen in the photo looping through all twelve expansion boards.)

The driving software is available to interested inquirers as an example of how to program the I/O boards on a AVR200 I2C expansion bus from BASCOM.

This masterpiece was created and programmed by Adrian Hoad, a model train enthusiast and JED's PCB designer, who passed away recently after retirement. RIP Adrian. See Adrian's trains and Emett.

Adrians tester