RS232 protocol

The RS232 protocol has been around for many years now. There are various versions and we have to be aware that non-standard applications are used often. The main aspects are the sockets and plugs and the packet sending rules.

Analog inputs

Most sensors are detected via a changing voltage that's fed into the analog inputs using voltage division.

 There are some good introductions to analog voltage on the Arduino including this one.

And here's the Arduino tutorial about the analog pins.

The Arduino and the Mega 328 pinouts

LDR

Some good code and information here.
Light dependent resistor circuit. See http://www.ladyada.net/learn/sensors/cds.html

The LED

Good diagram of LED pinout

Some more LED information

The maker movement

Massimo Banzi, inventor of Arduino, talks about maker revolution in TED talk.

The kits are designed for inventing
https://nicegear.co.nz/electronics-gear/sparkfun-inventors-kit-v32/

Adafruit are leaders in the Maker Movement
https://www.adafruit.com/category/17

Link to Wikipedia article on open source hardware

The maker culture explained


Dunedin's makerspace

Hackaday uses existing stuff to repurpose into something new.

Atmel, big US microprocessor company, embraces Maker Movement