Talk:Charlieplexing

message: is backwards!
—Preceding unsigned comment added by Fastfourier (talk • contribs) 15:18, 11 October 2010 (UTC)
thread_title:  The clock in the picture 

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thread_title:  External links modified 

message: LEDs are not capable to resist a high Reverse Vorlage. I think it Works but is Out of specific range.  — Preceding unsigned comment added by 2A01:598:9180:C013:C138:5C39:30DE:C3AC (talk) 20:15, 2 December 2016 (UTC)
replies: text: Diodes are produced so that the reverse voltage is higher than the forward voltage and voltage on any diode in charlieplexed circuits will never be higher than forward voltage. Therefore it is impossible to exceed capabilities of a diode. -- wikimpan (Talk) 02:44, 7 June 2017 (UTC)
thread_title:  Reverse voltage 

message: I believe that the article has multiple grave issues. The article should be cleaned up, but since I am unsure what the authors of the previous edits actually meant, I am also not very willing to do that without first getting the following questions solved.
* The Maxim’s article and the patents describe something different than what the article describes. All of them contain descriptions that incorporate, as a part of the solution, circuits that reduce pin count that resemble the article’s subject, but neither of them clearly describes exactly this approach. Do we have any good sources that clearly describe this particular thing? Because right now it seems like the article is based primarily on someone’s own research on the topic.
* The structure is somewhat odd. The ideas on which charlieplexing is based are described in a paragraph entitled “Traditional multiplexing”.
* The order of sections is strange too: first there are conclusions on how charlieplexing pin count, then there is a description of the ideas that form the base for charlieplexing, the overviews itself is mixed up with them. Shouldn’t it be different?
* The reason charlieplexing works is that the conducting diode will keep voltage on any other branch not higher than its forward voltage. This guarantees that voltage on any other diode will never exceed either its forward or reverse voltage. However the circuit presented in “3-pin configuration for different LEDs” has no such guarantee, because — due to resistors — all the branches receive full voltage from the microcontroller and more than one branch may be in conducting mode. There are very specific scenarios with specific output voltages, resistance values and matched LEDs in which this may work, but it is not a typical case — and the article doesn’t even discuss the thing.
* The requirement described in the previous point is not clearly highlighted in the article.
* The article misses a description of Y-s from the two bottom images (1, 2). It is also not clear how these circuits should work.
* The whole article sounds like a tutorial on how to build a charlieplexed circuit, not an encyclopedic description.
* The section on refresh rate seems to describe a problem with a particular implementation from the Maxim’s article: not of the general approach.
* LEDs often have a maximum peak current rating as well as an average current rating.: certainly, but how does this relate to the section?
* In the diagram above it can be seen that if LED 6 has a 4 V forward voltage: which diagram — there are four of them.
-- wikimpan (Talk) 03:11, 7 June 2017 (UTC)
thread_title:  Multiple serious issues 

message: "Indeed, flicker cannot usually be seen when its frequency is greater than the so-called critical flicker fusion frequency (CFF), which is usually between ~60 and 90 Hz, although the frequency varies with the characteristics of the light and the observer." ... "during a saccade, the flicker could
be seen as a trail of lights even when the frequency of the flicker was as high as 2 kHz."
I've tested my own eyes and they match this, perceiving 80 Hz flickering straight-on, and 1 kHz during saccades. — Omegatron (talk) 23:58, 24 July 2018 (UTC)
thread_title:  Flickering 

message: While the code example might be useful as reference for novice hobby-developers, its too long, bloats out the article, and adds little of informative value. I think removing it will improve on the consistency and readability of the article.
-- (unsigned) 2018-09-04T12:31:11 by 2001:700:300:1463:6868:41ca:8798:e290
I agree. There are many examples of such code already online. Touchscreen1  — Preceding unsigned comment added by Touchscreen1 (talk • contribs) 10:42, 30 December 2023 (UTC)
thread_title:  code example 

message: "Charlieplexing requires frequent output changes, through a method known as multiplexing."
I'm not sure I'd say that the frequent output changes are achieved by a method known as multiplexing. Rather the multiplexing is achieved by very rapid output changes.
It's an OKay article. I've been using this technique for years, but never heard it called CharliePlexing! InfoPirate (talk) 22:54, 26 January 2023 (UTC)
thread_title:  Good, useful article, but care needed