Class 21:  Nov 15

More SPECIAL topics:

Raspberry Pi as a simple webserver.  Host your own blog.

Did you know your BS2 version is already a webserver? click on   (or whatever is the IP address of YOUR pi).

WebServerOnPi – the PDF.


Class 22: 29 Nov

  • digital expansion chip mcp23017 – 16 more digital pins for $2 (use 8: get 128 new pins for $15)

Those wanting an early start:

How we will wire it to the Raspberry Pi. CLICK

Scripts on the Scripts page as usual.


Class 23: 6 Dec 2014

LCD (i2c connection) with Arduino.bpk

We need to download a LIBRARY and a SKETCH.

“That’s our device shown.”  (The LCD module itself is standardised across manufacturers, but there are VARIOUS hobbyist “i2c backpack” boards for the LCD module. The picture is OUR one. They all have differing internal wiring, and hence differing sketch code is needed! It can be a right pain trying to examine circuit boards from eBay to see which way the relevant 8 pins of i2c chip connect to which of the 16 pins on LCD main board. The eBay seller would not have any idea!)


As the article says, download the library ( from

Unzip it and put contents in a new folder “LiquidCrystal” inside “sketchbook/libraries” on PC.
(If there was already a “LiquidCrystal” folder in your library area, rename it to something else.)


The “examples” that are bundled with the library don’t match our backpack.

The article above goes on to say where to download correct sketch from:

Paste it into an arduino window and save sketch as “lcd” or similar.
All the numbers in line 13 of the sketch   (lcd(0x27,2,1,0,4,5,6,7);)   are the correct i2c address and internal wiring pattern for our backpack.

It should compile & work !!!



Then – SUMMER BREAK – resuming 21 March 2015