This article is a continuation of Arduino hardware part 1 that talks about Arduino Board, COMMUNICATION CABLE (Serial / USB), Arduino power supply, PC / LAPTOP +-USB Serial Adapter. In this section we will discuss more about Arduino Hardware : With what Arduino elements can interact?, Arduino Prototyping, etc.
The Arduino is based on the ATmega168 chip or Atmega8. We take as reference with USB board. The following is an explanation of the pin in the image above. Starting from the top center of the pin clockwise :
· Analog reference pin (orange)
· Digital Signal Ground (green light)
· Digital Pins 3-13 (green)
· Digital pins 1-2 / O serial port: TX / RX (dark green)
· Reset Button (dark blue)
· Input circuit serial programmer (turquoise)
· Analog Input Pins 0-5 (light blue)
· Power and Ground Pins (power: orange, earth, light orange)
· Input from an external power supply (9-12V DC) – X1 (pink)
· Switches between external power supply or power through the USB port – SV1 (purple)
· USB port (yellow)
Arduino Board Prototyping
This board is designed to incorporate additional basic Arduino hardware design. It incorporates an array of holes in which to assemble our additional hardware. You do not have serial or USB, making it necessary to have another board to program the chip. In their absence you can use a parallel programmer or an AVR ISP.
It is the last version in which you are working. Eliminates the need for cables to communicate with a PC or other Bluetooth device, such as a mobile phone. The design still need to debug it, so they are not yet available and the scheme or CAD files.
If you want to directly use the ATmega8 chip on PCB board or breadboard, without wanting to use Arduino parts which is not necessary, The Arduino schematic is available here for you.