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The story of the Amazing Arduino was based on ATMEL, a rival company that was later bought by or merged with MICROCHIP.

Arduino RS232#

Nicholas Zambetti / CC BY-SA

This is now a museum piece! It is no longer available commercially or in production.

This was the Arduino when it first came out in 2005! Not much has changed hardware-wise, except for replacing the now-obsolete Rs232 serial interface with a more useful USB one. The speed of the processor has also increased.

The most important changes are:#

  • Price
  • Availability
  • The Chinese manufacturing industry underwent a revolution.
  • Numerous alternative suppliers
  • Arduino boards, which are designed for specialty uses, differ significantly in their hardware.

Old was somehow better

One of the good things about the older non surface mounted arduino boards that carried a DIL (dual in line) package, was that these boards were useful for blowing an atmega chip and then using this in another board.

Every day more and more chips are moving toward surface mount. This is just about acceptable, so long as we can still solder them, but the QFN chips are lead-less wonders and some of these are less than a mm wide!

I cannot even see these things properly never mind the idea of soldering them!


There is a comprehensive list of Arduino and Arduino compatible boards on This Wikipedia Page .

Arduino Uno R3#

This is perhaps still the most common arduino and the basis for the most compatibles.

loudmouth / CC BY-SA

The Arduino Uno R3 uses an ATMEGA328.

  1. It is worth noting that the most up-to-date versions of this including the low cost Chinese versions use only surface mount components.
  2. It was considered an advantage to be able to program the ATMEGA chip while it was on board, so that you could use the chip in another circuit.
  3. However, this was not really satisfactory as the socket is not ZIF and so there is a risk of damaging the chip pins and the socket with repeated use.

Arduino Nano#

Adventist / CC BY-SA

The Arduino Nano also uses an ATMEGA328.

This board is all surface mount and is designed to be used as a component on a breadboard or as a component on a PCB.

There are extremely low cost versions of this board on the market. The end user price is comparable with the through hole version of the ATMEGA328