Arduino Stand Alone

The following outlines how to build a stand alone Arduino on a bread board. This tutorial is based on the original explanation at the Arduino site. I have not included a schematic here -- if you follow the one at the Arduino site note the listed errors -- they are corrected in the info below.

Note: I am using a resonator with built in caps -- not a crystal. The crystal breadboards more cleanly -- but the oscillator reduces part count (sort of).

Parts List

  • ATMEGA168 chip (blank)
  • 16M crystal
  • reset button
  • 10K resistor
  • jumper wires

Getting Started

Let's first look at the full system that we will be making so that you can plan your breadboard. Power is to the left, the micro controller with reset button are in the middle and a 7404 and DB-9 serial connector solution for communication is on the right. Matching wire color isn't necessary -- but keeping your board tidy makes working with this arrangement easier.

Arduino Standalone


On a MAC this serial strategy requires a serial to USB converter -- i.e. a KEYSPAN adaptor. If you want (or need the room), the 7404 and DB-9 can go on a separate board -- just jumper the power and GROUND between the boards and connect the serial RX and TX. You could use an FT232 serial to USB breakout board by Sparkfun and skip the 7404 / DB9 / KeySpan adaptor.

Connections

Orientation: Start with your bootloaded Atmega168 on the board. Like all chips, start with the notch / pin 1 (red arrow) indicator to your left. Physical pins are now labeled from 1 to 28 by counting in a counter-clockwise direction. Note the orientation of power busses -- red to the top! (This isn't technically critical -- but it makes following the photos easier).


Step 1: Power -- First connect power to the chip. The jumpers on the bottom power the chip, the jumpers on top are for analog (see chip data sheet for accurate details).


Step 2 -- Oscillator: Finish power connections by jumpering pin 20 to 5V. Then connect the 16M oscillator. The oscillator has 3 legs. The middle leg goes to ground (black wire) the outer legs go to pins 9 and 10 respectively. The oscillator is internally symmetrical so it does not matter which way it faces -- just get the outside legs to pins 9 and 10 on the micro controller.


Step 2b -- Oscillator: Another view.


Step 3 -- Reset :The RESET button is needed for programming the arduino (see the programming section for variations on this). It is also good to have one when things go wrong and you need a restart! Check the orientation of the button. The one I have fit conveniently in only one direction. When it is closed PIN 1 connects to ground via yellowwire-switch-blackwire. When not pressed, yellow and black are disconnected. Any switch the accomplishes this arrangement will do.

The 10K (brown-black-orange) resistor is needed even if you don't have a switch. It pulls the RESET high and makes sure the micro controller. stays on, even if someone's cell phone rings!

Completed Circuit

Step 4 -- Check your work. If your board looks like this you should be good to go!

Next: Serial Connections


[TOP]

(This Page Last Updated: January 14, 2008ate --> )