Channels ▼

Al Williams

Dr. Dobb's Bloggers

Intermediate User Interfaces for Embedded Systems

December 06, 2010

I tend to classify my designs by two criteria: the time response required and also the user interface required. Some of my designs have no user interface. A few have buttons and LEDs. Some have the usual LCD display with a few buttons or maybe a keypad. And still others have full-blown touchscreens.

It has always struck me that there's a pretty big gap between a text-only LCD and a few menu buttons and a full VGA display running Linux.

I haven't tried them yet, but buttons with built in LCD displays caught my eye today. Maybe that would fill the gap I've notice.

These aren't dirt cheap (a little more than US$30 each in singles) but the specifications sound good. Each switch has 64x32 pixel graphical LCD and an RGB backlight can produce over 10,000 colors. The switches initialize themselves so you only need to send data to them if you want them to change appearance. An SPI interface lets you program it via two of the six terminals (power, ground, SPI, and -- oh yeah -- the actual switch closure.

The RGB backlight makes these unsuitable for low power use. With a single LED on, consumption is about 25mA and if you get fancy that can go up to 60mA.

These look like they'd make a pretty futuristic looking front panel.

Related Reading


More Insights






Currently we allow the following HTML tags in comments:

Single tags

These tags can be used alone and don't need an ending tag.

<br> Defines a single line break

<hr> Defines a horizontal line

Matching tags

These require an ending tag - e.g. <i>italic text</i>

<a> Defines an anchor

<b> Defines bold text

<big> Defines big text

<blockquote> Defines a long quotation

<caption> Defines a table caption

<cite> Defines a citation

<code> Defines computer code text

<em> Defines emphasized text

<fieldset> Defines a border around elements in a form

<h1> This is heading 1

<h2> This is heading 2

<h3> This is heading 3

<h4> This is heading 4

<h5> This is heading 5

<h6> This is heading 6

<i> Defines italic text

<p> Defines a paragraph

<pre> Defines preformatted text

<q> Defines a short quotation

<samp> Defines sample computer code text

<small> Defines small text

<span> Defines a section in a document

<s> Defines strikethrough text

<strike> Defines strikethrough text

<strong> Defines strong text

<sub> Defines subscripted text

<sup> Defines superscripted text

<u> Defines underlined text

Dr. Dobb's encourages readers to engage in spirited, healthy debate, including taking us to task. However, Dr. Dobb's moderates all comments posted to our site, and reserves the right to modify or remove any content that it determines to be derogatory, offensive, inflammatory, vulgar, irrelevant/off-topic, racist or obvious marketing or spam. Dr. Dobb's further reserves the right to disable the profile of any commenter participating in said activities.

 
Disqus Tips To upload an avatar photo, first complete your Disqus profile. | View the list of supported HTML tags you can use to style comments. | Please read our commenting policy.
 


Video