A AVR Development Board

The internet is full of projects with Arduino. For a while the information about the ATMEGA328 microcontroller is missing in all the Arduino data. This Insctructable want to recuperate the beginning of how to develop projects using the AVR microcontrollers without Arduino, specifically the ATMEGA328.

It is a simple development board for the mentioned microcontroler. I named it: Claudino.

In the project, the materials, are:

1x ATMEGA328

1x LM7805

1x DC power jack

1x Push-button

1x LED

2x 0.1uF Capacitor

1x 10uF Capacitor

1x 330 ohm Resistor

1x 10k ohm Resistor

1x 1N4001 diode

Some pin head and header

Step 1: Design the Circuit

For this instructable, I used the software Eagle of Autodesk. This coftware is a powerful schematic and board designer with a lot of components to be helpful in this process. I used the information about the minimal system contained in the AMEGA328 datasheet. In the board, I used pinhead to representate the header for the GPIO and the same pinhead to connect the ISP programmer and an auxiliar port for the external crystal.

For the alimentation of the board I used a DC barrel jack and a LM7805 regulator to have the 5v necessary in the microcontroller. The board included a reset push-button and a status LED.

Almost all the design is colocated in the bottom face of the board, using only a jumper in the top face.

Step 2:

First of all, it is my first time using the acid process to make PCB's, another time I used the CNC mill at my school, but not all the times are available for the quantity of students. Now I used the acid method because I don't have another PCB mill available.

The first step is print the bottom face of the board in a piece of paper (using a high quality of tonner), after that, the copper board is colocated with the copper face in with the printed circuit and is fixed using tape, and then is time to ironing with the iron (of course) with the objective of heat the copper face. Wait ten minutes and quit the piece of paper of the board, you will see the tonner in the copper. Quit all the paper remaining and wash with cold water.

Now is the dangerous step. You must use a pair of latex gloves, safety galsses, and you must do it in a drafty place. In a plastic or glass container mix two parts of ferric chloride and a part of water. Put the board inside the mix and wait to have only the copper tracks. Wash the board with a lot of cold water and be careful to save the used acid.

When the board is clean, now you can remove the excedent board and make the drill's. Be careful with the copper tracks.

Step 3: Solder and Bla Bla Bla

With a multimeter, probe continuity between the different points of the copper tracks. The final step is to solder all the components on the board. It es maybe the most important step in the process. because the board is now done. You can now use a marker to place labels on the board, and you can name the board as you want.

Soon, I will show you how it works with a lot of small and large AVR projects. The programming will be realized with you favorite software and hardware, like avrdude with USBasp or whatever.