Basic Displays which have enjoyed success w/TM4C123...

It should be noted that the displays grouped above are, "Universal" in nature - thus may be used w/most ANY MCU from any vendor.

Such universality enables great, "Flexibility & Freedom of Choice" (user may choose just which MCU Ports/Pins to devote to the display!)

Often - such universality/flexibility trumps "more focused - thus limited - pre-packaged designs" - which are likely to exceed "medium cost" and ALWAYS exceed "low cost."  

Worse still - if (likely when) the user switches to another MCU - the initial "convenience" (for which users pay dearly) converts to a nightmare as "such packages" are in NO WAY Universal.

There exists a WIDE Range of Display types, sizes, capability - choosing "pre-packaged" VASTLY LIMITS the "scope" of user selection!

Hello Amit,

Note the post was in direct response to the recent request of a poster - and sought to "showcase" - just a FEW - of the multitude of displays available to users.

The selection process in itself is very rich - and varied - which is why firm/I and (ALL of our clients) reject the (harsh) limitations imposed by, "Plug-In Solutions" which SO DRASTICALLY REDUCE/ERODE User's "Freedom of Choice!"   And - by definition - preclude & PREVENT USE of the "Plug-In Solution" in ANY OTHER Application!   (i.e. non-specific EK)

Firm/I are equipped to aid re: Selection, Availability - while we DO have code - our belief is (that) should flow from the MASTER. (Mr. Ashara)

Two cents...
On this company, we do use HD44780 based display as well. Both led back-illuminated as well as OLED.
We once "jumped happy" to migrate from LCD into OLED, for we also agree that visibility is WAY better - but we figured that the oled consumption is slightly higher, and hence a few products still use "old" lcd with backlight. Interesting, LCD power requirement is lower ONLY provided that the product is used during daytime... for that backlight is a old hungry *** at ~100mA.
A few centuries ago we looked for libraries for that display on the web... either a decent open source or at least some inspiration. Finding one seemed to take longer than writing the basic code, hence we took the second path. And to this date, our library is still very naive and ugly... but works.
My guess? Tivaware itself should offer a HD44780 control utility on their package... :) They will probably remain on the market for long, and a reliable pack of SW would make "us customers" faster, happier, even more loyal!

Bruno Saraiva said:

They will probably remain on the market for long, and a reliable pack of SW would make "us customers" faster, happier, even more loyal!

And, it does not clutter the MCU (performance and code space - wise) like those bit-banged QVGA parallel bus displays.

BTW, how is the aging issue with OLEDs currently ? In those early days, the bright colors tended to fade quite quickly ...

cb1_mobile said:

the "Nav's switch code" is impressed upon the Lcd's data bus - but in such a way that a switch depression CANNOT interfere w/a display write!

Typical cb1, dropping teasers hidden amongst dense content of a longer post...

Will he care to elaborate the "clever implementation"?  :)

I would also not mind to visualize the mechanical arrangement on this rocker navigation switch... I had never considered using these, yet "why not???"

Bruno Saraiva said:

Typical cb1, dropping teasers hidden amongst dense content of a longer post...

My (continent jumping) friend - "Really, "teaser-dropping" AND "hiding" - via post density?"     My mind's eye conjures our leader Amit thinking, "Poster Bruno has read, "one too many spy novels!"  

I'm but a humble reporter - you raise my status - provide too much credit...    That said - placing such, "item of note" (deep) w/in a writing - "harvests" (most always) ONLY those of the most serious bent!

To the specifics:

One of our "giant" clients requested "best effort" to create a, "Portable, Miniaturized, Transactional port" able to (both) "Send & Receive" (small) yet critical data.   We chose a 2x8 character module (our own, of course) and the "5-Way NAV Switch" presented the smallest "physical footprint" and (very) satisfying User feedback!   (and the up/down entry capability proved intuitive - enabled speedy & precise data entry.)   The 5th switch, reserved for data entry/transmit - resulted from an inward, "Press" of the Navigation's "button."   (that was a part we had custom designed - then molded)

Clever implementation - no doubt - yet you/others surely can identify (multiple) solution methods - perhaps (some) superior to mine!   That's the BEST use of this forum - is it not?   If I describe - forum "brain-work" grinds to a halt.   (but for Robert, f.m., Chester and of course Amit)  

Caveat Venditor...  (let the Seller beware)

f. m. said:

how is the aging issue with OLEDs currently ?

Not a million units experience here either... But the few yellow on black 2x20 oled pieces we started implementing some 3 years ago are still quite good. They come from a major Taiwan manufacturer.

Bruno Saraiva said:

... black 2x20 oled pieces ...

That sounds like a character displays. I'm pretty sure the aging issue (fading of light output/efficiency) is much less noticeable on those. More so for "True Colour" displays - that's why they ended up mostly in fad stuff like mobile phones with a  development cycle of 6 month and a life time of about 2 years.

I had been witnessing experiments to use OLEDs for lighting purposes, which obviously didn't quite pick up pace ...

However, I learned a few tricks of this industry. So for instance starting with about 70% output for those LED lightings, to "extend" the perceived live time.

f. m. said:

starting with about 70% output for those LED lightings, to "extend" the perceived live time.

A "dirty" trick that my friend...

Might "sensing" of the ambient light - at/around the display - enable "automatic brightness control" thus extending display's "effective" life?

Along that 30% "hold-back" of power - is not that Usain Bolt's "M.O." - for the first 40-60 meters - before the after-burner ignites?

* M.O. (modus operandi - the individual's "normal" pattern of behavior - often used to identify criminals.)    (and sometimes - even posters)

cb1 said:

A "dirty" trick that my friend...

Might "sensing" of the ambient light - at/around the display - enable "automatic brightness control" thus extending display's "effective" life?

To explain some more details: as you might know, lifetime of LED lightings is mostly limited by diminishing output, total failure is less probable (if the electronics get that old ...). It has a "half-life period, i.e. light output is only 50% after the given life time period.

When starting with about 70% max. output, one can prolong the period of constant luminosity, before the end user notices anything. This is done by increasing this 70% to 100% over time. BTW, the usual life time (half-life period) of lighting LEDs is about 20.000 to 50.000 hours. Any "ambient light" output control is relative to the current age-adjusted "maximum - about 70% to start with.

cb1 said:

* M.O. (modus operandi - the individual's "normal" pattern of behavior - often used to identify criminals.)    (and sometimes - even posters)

Curious that you mention "criminal" in connection with "lighting"  - just search for "Phoebus Cartel". And remember, Wikipedia is not exactly a paragon of truth ...

cb1 said:

I can see how you arrived at that (criminal) curiosity - yet "criminal investigation" yields (by far) the major use of "Modus Operandi." That was my point - and I tied in the "Multi-Olympic, 100 meter Champion" as a (simple) example.

Well, the "criminal" just jumped out at me. And reminded on said cartel. I think Usain Bolt is not dawdling the first 40 meters, at least when he wants to beat his own records. He might play with competitors from time to time.

cb1 said:

Indeed - for a general purpose (lighting) application - the "reduced output while "new"" makes perfect sense. However - in the context of an "Operator Panel" (as used here) our "Automatic Adjusting" feature has been well received. Suspect that (both) may have their place...

You are right - reducing initial luminosity to prolong the life time is not a "criminal" feature, compared to make it break after 1000 hours. And reduced power/temperature has the positive side effect of (electronics) prolonging life in general - think MTBF.

I don't like LED lighting for other reasons. For one, it is mostly PWM (yes, the light output), with uninvestigated side effects. Second, the light is spectrally very poor (low CRI). The psychological effects are mostly known, only not by the customers. And third, it's mostly too expensive (for me). I like sun light ...

For signage applications, it is optimal.

f. m. said:

So for instance starting with about 70% output for those LED lightings, to "extend" the perceived live time.

Actually, you might be increasing more than just the perceived lifetime.

Diode degradation would normally be due to migration of dopants or creation of defects. Reducing current will reduce heat generation (somewhat non-linearly) and since rate of both migration and defect creation is a function of temperature you likely reduce both. In addition there may be effects that are related to current density.

In OLEDs I would expect hydrogen bonds to be particularly significant and so humidity and moisture might be important as well, especially if the surface passivation isn't perfect.

Robert

cb1_mobile said:

might certain of the effects you/f.m. describe be classed as, "Electromigration?"

Yep. those dependent on current density (or field strength) could be described as electromigration. You would get some reduction in field strength with reduced current.  I hadn't thought of field strength being a contributor but it could well.

I'd have to spend time with the organic semiconductor literature to know what effects are dominant though.

Robert

Robert Adsett said:

I'd have to spend time with the organic semiconductor literature

Or - the aforementioned Physics Departments - if they can "break" from their "Void" investigations - may honor us w/their comments...

Long live Basic Displays!

Robert Adsett said:

Actually, you might be increasing more than just the perceived lifetime.

I think I mentioned this in one of the next sentences. But that leads me to another disadvantage of LED lightings. They are missing the infrared emission component. That means, all heat (power losses) must be dissipated by convection - thus the bulky (and ugly) heatsinks.