ATtiny24/44/84 Mini Board

v1.3

This is an all-in-one module for Atmel ATtiny24/44/84 8-bit microcontrollers and all necessary components to run them. Having a microcontroller module is nice because it reduces the amount of redundant design in projects using microcontrollers. You only need to provide 5V power and connect to the I/O lines to make a prototype microcontroller circuit. This design easily connects to a breadboard or a subcircuit with header pins and can also be wired directly for a permanent installation. Subcircuit design is greatly simplified by a modular approach because there are no traces blocking the way to the microcontroller pins. All traces on the microcontroller module are essentially on a different level making connections much easier.

The idea for this circuit came from tinkerlog where they made an identical circuit but for different microcontrollers. I decided to use the ATtiny24 because it was low cost (approx. $1, similar to the smaller ATtiny13) and had a fair number of I/O and analog inputs. This microcontroller will work for most simple projects where an Arduino or something similar would be overkill. It would be nice if it had more pins for some projects but it's a good platform to start with.

This board includes a crystal, filtering capacitors, a reset switch, ISP programming header, and a power LED.

Finished board with ATtiny24 microcontroller and necessary components (crystal not shown, using internal oscillator)

Headers were installed and the board was plugged into a breadboard for easy prototyping.

ATtiny24 mini board plugged into a breadboard. A series of 8 resistors and LEDs were connected for a simple I/O test

I attempted to make the board as small as possible and keep top traces to a minimum. The two top traces can be replaced with small jumper wires and will end up hidden beneath the microcontroller. It's a good idea to use an IC socket in case you end up burning out an I/O pin or destroying the microcontroller in some other fashion.


Eagle Design Files

Cadsoft Eagle pcb schematic [ .PNG | .SCH ]

Cadsoft Eagle pcb layout [ .PNG | .BRD ]

References

  1. Tinkerlog page showing mini boards for different Atmel microcontrollers
  2. Atmel ATtiny24/44/84 datasheet