PIP Micro Web Browser v0.7 Suitable for 32KB Arduino/ATmega use.

(c) Chris Anderson 2014.

Creative Commons license: Creative Commons Attribution 4.0 International License http://creativecommons.org/licenses/by/4.0/

PIP is a functional but incomplete web browser for Arduino and runs well on an Uno. It can download and render plain HTML (no images, CSS or Javascript) and follow embedded links. It's joystick controlled and uses a 320x240 LCD screen for output.

The Ethernet and SD card libraries use about 20KB of code, so the LCD driver, HTML parser and renderer squeeze in under 12KB.

Requires:

• Arduino Uno or similiar ATmega 328 powered board
• Wiz5100 powered Ethernet board with SD card slot (SPI CS = 10 & 4)
• 320x240 TFT LCD screen (SPI CS = 9) Found here: http://tinyurl.com/tftlcd
• Analogue joystick with button (PS2 style)

Installation:

• Plug an SD card (MAXIMUM 2GB) into your computer and copy the file "CACHE.HTM" from this enclosing folder into the root level of the card.
• Download the file "HOME.HTM" from the URL below and put it in the enclosing folder. Then copy the file to the root level of the SD card. https://www.dropbox.com/s/v8h2d94uxxcw1oj/HOME.HTM?dl=0
• Put the SD card into your Ethernet shield and upload PIP to your Arduino.
• Rename the enclosing folder of this file to "PIP_07.ino".
• Copy the enclosing folder into you local Arduino sketch folder, as per usual for new programs.

Wiring for LCD: Name Pin

• SCLK 13 Clock
• MOSI 11 Master Out - Don't change or you loose hardware assisted speed
• CS 9 Chip Select
• DC 8 Data/Comand
• RST 7 Reset
• LED Arduino 3.3v
• VCC Arduino 5v
• GND Ground

Wiring for joystick:

• VRx A0 - Analogue input 0
• VRy A1
• SW A2
• VCC Arduino 5v
• GND Ground

Notes:

Handles a sub-set of HTML tags. See tags.h file for list.

HTML pages over 20KB or so can stall and fail somewhat randomly. The Wiz5100 just doesn't seem to like dripping data to an Arduino much. Over 1KB/sec download speed can be cosidered 'good'.

Occationally when the browser crashes during a render, the HOME.HTM can get corrupted. Just copy the file in the enclosing folder back onto the SD card.

Due to poor Ethernet and SD card interaction on the SPI bus, the cace file on the SD card is held open as long as possible and only closed and re-opened during HTML download and parsing. That seems to make things ore reliable.

HTML files are parsed and made partially binary before being stored on the CD card. File are generally around 50% smaller when unused junk is removed. The stored file will be truncated to 64KB as 16 bit pointers are being used for page and URL indexing. May fix this by going to relative pointers.

Currently, URLs over 90 characters in size are truncated. This will undoubtably break them, or results in 404 errors. Which aren't handled well yet.

The LCD screen is used via a custom library (very similar to the Adafruit GFX library) which only implements rectangle and character drawing to save space. As only rectangle drawing and the print command are used, it should be easy to adapt PIP to use a different LCD.

Doesn't do images. Come on, there's only 2KB of memory and a tiny screen to play with! JPEG parsing might be problematic as there's only 2KB of program space free.

Forms are not even attempted. There's no keyboard, so good luck with that.

To do: Handle state case when a page break the middle of a tag.

v0.7 14/10/2014 Fixed exception for <script> and <style> tags. Improved resiliance to buffer under-runs with slow ethernet connections.

v0.6 1/10/2014 Indexes in-HTML links, shows current link, steps through links activates links and handles ethernet buffer under-runs

v0.5 17/9/2014 Parser re-written as purely state-based, fixed SD card/Ethernet conflicts - somwhat

v0.4 3/9/2014 Rebuilt and renamed browser as PIP, indexes pages, custom LCD libray re-written, optimise parser

v0.3 18/4/1014 Custom LCD driver library added, buggy

v0.2 27/3/2014 Downloads and parses basic HTML pages

v0.1 13/3/2014 Download and display concept, Muzayik