<story><title>Don’t use 7-segment displays (2011) [pdf]</title><url>http://www.harold.thimbleby.net/cv/files/seven-segment.pdf</url></story><parent_chain></parent_chain><comment><author>afandian</author><text>In Oxford city centre, and probably elsewhere, they replaced the live signage at bus stops. These tell you when the next bus is due, the time and date, etc.&lt;p&gt;They used to be amber LED matrixes. High contrast, high legibility, low resolution.&lt;p&gt;Now they are colour LCD panels. High resolution, high tech, probably high cost. Now they can show the logos of the bus operators, smooth scrolling text and any arbitrary images. None of which anyone really needs except perhaps the egos of the bus companies.&lt;p&gt;And they are &lt;i&gt;completely illegible&lt;/i&gt;. The viewing angle is limited, the text is smaller, unnecessary stuff is there because the implementors can.&lt;p&gt;Careful what you ask for.</text></comment>
<story><title>Don’t use 7-segment displays (2011) [pdf]</title><url>http://www.harold.thimbleby.net/cv/files/seven-segment.pdf</url></story><parent_chain></parent_chain><comment><author>malwarebytess</author><text>What a quirky paper. I worked at a major winery that had dozens of tanks, up to 100,000 liters each. A single failure in a tank represented many millions of dollars. Our extremely expensive micro-oxygen pump used a standard 7-segment display combined with little red LEDs representing On&amp;#x2F;Off next to a list of tank numbers. The 7-segment display was used to read and to set the units (μg, mg , etc), amount, and rate of oxygen delivery. I never made the mistake of misconfiguring, but one of the senior Winemakers did resulting in some very angry customers, a 7 figure loss, and many contracts.&lt;p&gt;I&amp;#x27;m left with two opinions: 7-segment displays are not usually fail-safe, and have the potential to be fail-deadly (figure 1). In my entire life I&amp;#x27;ve never had occasion to use a tool with a 7-segment readout, handheld or otherwise, that actually failed or that I misread due to ambiguity.&lt;p&gt;So, I think a better conclusion would be don&amp;#x27;t use 7-segment displays in important places.</text></comment>