[chbot] Arduino for $3! & link for 2.2 inch touch screen

[Volker Kuhlmann]

On Mon 20 Oct 2014 22:11:24 NZDT +1300, Stuart Brown wrote:

> Here are links to the Arduino boards and the little 2.2 inch colour
> TFT touch screen I had at the meeting tonight:

>  * Screen -
>    http://www.banggood.com/2_2-Inch-Serial-TFT-SPI-LCD-Screen-Module-HD-240-X-320-5110-Compatible-p-912854.html

Have looked more into TFTs for arduino. The chip used to drive the
display is a critical factor of course and can usually not pinpointed
reliably on Chinese trade sites (ok so what's new). A previous buyer's
comment might confirm.

Most/all of the common chips are supported by the UTFT library by
Henning Karlsen. He's very active and does good work, but UTFT is
extensive, general purpose, and said to be very slow. It also requires
102% of the available 100% code space on a 328 - just for the library,
nothing useful done yet. --> No use on small arduinos.

Feasible alternatives are the libraries available from adafruit on
github for various chips. The demo programs compile to 15-19kbyte.
Effectively this means don't buy anything that doesn't have one of the
adafruit chips. 

Additionally, there's an ILI9225 adaptation here:
https://github.com/Nkawu/TFT_22_ILI9225/wiki

1.8 Inch Serial SPI TFT LCD Display Module With Power IC SD Socket
http://www.banggood.com/1_8-Inch-Serial-SPI-TFT-LCD-Display-Module-With-Power-IC-SD-Socket-p-909802.html
Uses Samsung S6D02A1, adapted library here:
https://github.com/zigwart/Adafruit_QDTech

Also needed for all the adafruit-based ones:
https://github.com/adafruit/Adafruit-GFX-Library

I have not tried any software yet because I'm still waiting for the
modules.

Note both above modules are 3.3V only! For the 2.2" one people report
success with series resistors on 5V. The ones who blew it are keeping
quiet...

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.