Fubar Labs

The Internet

More than 3 billion people are now using the Internet, according to the United Nations agency that oversees international communications. The number of Internet users has increased from 738 million in 2000 to 3.2 billion in 2015, according to a new report from the International Telecommunication Union.May 26, 2015

As of June 2017, 51% of the world's population is on internet.

Ethernet & TCP/IP Networking

The following is a powerpoint presentation I created quite a while ago, I still think its relevant. It is a little bit old, but still very useful.

Webpage design

Since our student members have a mix of Windows and Apple Laptops, software design will focas on displaying embedded microcontroller data within a webpage. The premier place to go on the Internet to learn webpage design is W3Schools.

Arduino Networking with Ethernet - And Webpage design

This class will be focased on using the plug-in Ethernet Shield. We explore programming and communication using Arduino built-in Libraries for embedded websites on Arduino. We will use a Bootstrap website design, in a embedded Arduino webserver, to display analog measured parameters on a viewable web page.

Assigning a good IP address to Arduino

You will need to assign a good IP address inside your Arduino Webserver or Webclient program. What constitutes a good IP address? The IP address MUST be on the same subnet as the Ethernet port is assigned on your PC or laptop. There are 4 classes of IP address, A, B, C and D. Each class has a different range of IP address subnets. Forget about Class A. You either have class B or Class C or Class D. Each has a smaller number of host computers allowed, respectively. YOU NEED TO ASSIGN AN IP ADDRESS WITHIN THE SUBNET OF YOUR COMPUTER'S ETHERNET PORT

The take away is that you want to asssign the IP address of your Arduino, as one larger that the Ethernet port on your PC or laptop. Example, my PC Ethernet port is assigned IP address to 169.254.75.103. So I will program the Arduino to IP address 169.254.75.104. Do this with the "IPAddress ip(169, 254, 75, 104)" declaration in your program. The Local IP should be close in mathamatical value to the Host IP port address.

Open a DOS command window on your PC, and type in >ipconfig

On Apple or Linux, look for a Linux command shell, and type in >ifconfig

Look at the IPV4 addresses assigned to Ethernet interfaces. We are trying to track down a valid IP subnet so we can assign a good IP address to Arduino Ethernet program.

Issues with local Webserver access from the wider Internet (at home).

Most consumer Internet connections involve a dedicated media specific router for broadband access. This device may (probably) include a firewall to prevent unauthorized internet (outside home) users from gaining access to resources behind your firewall/router. This normally involves Network Address Translation, to hide your computer from outside access.

There is also a small issue with fixed versus dynamic IP address assignment of your home subnet, by the broadband carrier. These issues may hamper the use of dedicated embedded webservers when connected at home behind a firewall.

Program examples

There are some program examples underneath "Ethernet" tab in the Examples within Arduino IDE

Ethernet Shield using Wiznet W5100 TCP/IP protocol chip.

The W5100 chip is a complete TCP/IP processor, with 16K Bytes of packet buffer storage. This chip provides an 10/100 Megabit Ethernet interface to the world, and a SPI interface to the embedded microcontroller. This chip offloads all the network processing of TCP protocol and provides raw data packets to the Arduino target CPU over an SPI interface at slower speed.
Wiznet W5100 product web page
Wiznet W5100 datasheet