AVR, Arduino, Raspberry Pi

AVR, Arduino

Arduino picture
Arduino is a board concept using Atmel AVR microcontrollers (MC). As a HW platform it is a set of pin compatible functional blocks. With some basic equipment it is easy to test and construct an own board concept with AVR chips. Or to use Arduino blocks combined or enhanced with own circuits.

Arduino Duemilanove and Arduino UNO is an 8 bit MC board concept based on MC ATmega328. Predecessors of ATmega328 are pin compatible ATmega168 and ATmega8 from AVR family. ATmega328 offers 14 digital I/O pins and 6 analog input pins with built in 10-bit AD converter and an analog comparator. Digital to analog (DA) conversion is realised as digital output using PWM modulation. A lot of interrupt events and sophisticated timer/counter system are also disposable.

The ATMega328 pins are mapped to the functions of Duemilanove board. Arduino pins to ports and pins of ATMega328 is on a cut of the Arduino board circuit diagram from Arduino board datasheet. The board is powered from the USB interface to a PC or as a stand-alone unit using power supply jack or pin. It works with 32 KB flash program memory, 2 KB internal SRAM, 1 KB EEPROM and a lot of registers. Using 16 MHz clock the unit runs 16 MIPS, most of the instructions are executed in 1 MCU clock cycle.

Disposable is also SW with an IDE and a special variety of C compiler. For Assembler and C there is also a free Visual Studio.
A compiler for Basic - BASCOM with an excellent IDE and simulator is available for testing as a demo version with a restriction.

Raspberry Pi

Raspberry Pi picture
Raspberry Pi Model 2 B specifications and board interface connectors:
900 MHz, 1 GB SDRAM, micro-SD slot with 8 GB micro-SD card,
4 USB 2.0, HDMI video port, 3.5 mm audio output jack,
10/100 Mbit/s Ethernet (8P8C),
17 GPIO pins,
micro-USB or GPIO power 5V, 800 mA.

Using the HDMI onboard connector of RPi to connect it to a display:

Raspberry Pi picture

The display controller card is placed under the display. In place of a HDMI-HDMI cable it is possible to use two connected HDMI connectors - a stright one and a bent one as on the picture. For typing is an USB keyboard and mouse needed or a bluetooth keyboard-mouse combination with an USB bluetooth dongle. Using OS Raspbian and programming in Python is the standard way.

Another solution is to use display and keyboard with mouse of a notebook. We need a Wifi USB dongle in RPi and the Wifi facility of the notebook. For RPi we have to enable existing SSH connection, no additional SW is needed. On the notebook we need to install PuTTY, or simple to download PuTTY.exe file from an Internet source. This way enables to work in text mode, for graphic another SW is needed.

Or for Python programming it is possible to install a Python programming environment under Win on the notebook in combination with WinSCP for file transfer between the notebook and RPi.