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Adafruit used to sell their 1.2" led backpack displays in 4 colors, but now only red or yellow is available.
I think i got one of the last green ones.. I have a friend that wants me to build her a GPS clock like the ones i made.
But i am unable to find any displays ready to use, Such as the I2c type I've been using.
I can find the I2c boards for the adafruit 1.2" leds.. and i found 1 place on Alibaba that has the Blue 1.2" But they want to sell them by the hundreds..
I could get a sample, for a few bucks, but they want 26$ for shipping.
I need a display that can handle 5v with no issues,and be larger than 1 inch.. and be I2c compatible if possible...
Anyone know of any sources..

Dacflyer,

Your still looking, Huh?

Well, like I said before.
Get a bunch of Blue Rectangle LED's.
A Protoboard, Wire, the Display Wiring Schematic.
And make up the display yourself.

Edit:
I came across this video: https://www.youtube.com/watch?v=r_yobwaBWr0
Give it a look.
The guy came up with a way to make large 7-segment displays using a WS2812B programmable LED strips.
He drives them with a Arduino.


Signed: Janitor Tzap

Hi. Alibaba is the wrong place :

----> https://www.aliexpress.com/wholesale?Se ... earch=true

Externet wrote: ↑Tue Nov 08, 2022 4:13 pm Hi. Alibaba is the wrong place :

----> https://www.aliexpress.com/wholesale?Se ... earch=true

Aliexpress doesn't have anything in a 7-Segment, 4-Digit display that's larger than .56 inches.
Except for single digit 7-Segment display modules.
There were 1.3 inches 7-Segment, 4-Digit display modules, but they are OLED.

So, unless you can find the person who horded a bunch of Blue adafruit 1.2" leds 4-Digit display modules.
{And can pry one out of their cold dead hands.}

I'd say your out of luck Dacflyer.

Hmmm..........
How about getting (4) 1.8" inch single digit 7-Segment blue display modules.
And (4) blue single LED's.
Then mount them on a protoboard, wire it to match up with the I2c board.


Signed: Janitor Tzap

Thought about using single 7-seg. and then driving them with the ol TPIC6B596 driver board. Have used these in several clocks before just different size digits. A bit more work, But doable.
Can't believe there isn't more variety out there for clock displays.

Have you thought about using the cut-able LED tape? They come in different voltages where each section can run off that voltage, or the whole strip. You could make some relatively large, discrete, 7 segment units. Check out Big Clive on YouTube for some of the stuff he's done with both the tape and the LED Neon strips.

* If you use the LED Neon strips, you can do custom shaping too. FranLab on YouTube has some unique displays that are highly stylized that could translate to that bendable tape.

ya, I have, but it's not feasible for anything small..
I think I might have found one.. Having to sweet talk the lady in china to send me a few samples..
this is one of the displays like Adafruit 1.2" displays. But in blue.. I'll have to order the Adafruit backpack board.. No biggie..

https://www.alibaba.com/product-detail/ ... 60005.html
I'm going to try and get me 4 of them. then I have what i need to make a few extras if need be..

you've been looking for that a long time, nice find. I've been forced into Ali a few times recently for things I used to get elsewhere too.

took a while yes... If these sell well later on, I might order others..
just waiting for them to arrive now..

Update to the Blue displays.. come to find out these displays need more power than the HT16K33 can supply, China Lied to me again..I told them i needed a low voltage Blue led display. the lady said the leds only need 3.2V to operate, But failed to tell me that the display had 2 leds in series per segment. So, Now i have displays i can't use. I'm sure there is a way to make an adapter board to interface the HT16K33 or can anyone recommend a chip that could work ? Otherwise the displays are useless to me.

Well, you could whip up a driver board with either BJTs or MOSFets (I'd think MOSFets would be easier on the HT16K33), or if you wanted to spend more (or probably close to the equivalent of the many single actives you'd need) you could get a chip that has multiples on it.

Search and sort your favorite parts place. Never know what you'll find.

One of these for each ROW - Your IC still uses +5V. RLimit is calculated from (higher) supply voltage minus 6.4 (2 LEDs) divided by LED current. Because of multiplexing the LED current may be larger than max continuous LED current.

The column outputs of the IC connect LED cathodes to common. But check spec sheet to see how much an "off" column output can take when a row it is connected to is "on". We may have to do something similar to isolate the IC. (maybe one PNP)

Cheers,

I figured why take chances with the IC. Good thing the transistors are only 25¢ each at Jameco. (you might even have something useable) Board space is the only "bad side". Maybe try one row and one column, then display a digit that uses that position, then a digit that doesn't.

Oh yeah, It can't be done with one PNP. A "low" from IC would turn it "on". But a "high" from the IC will not turn it (all the way) "off" either. With two transistors the PNP is "on" or "off" with 5V swing from IC. This turns NPN "on" or "off" even though its collector could be at more than 5V.

Could be done with FETs too. P-channels are harder to find. And the load on the IC is way less than direct LED drive even with bipolar transistors.

Re Cheer,

well, the thing is... Unknowingly I bought the backpack boards before i bought the led displays.
I was hoping to resolve the issue by possibly with an adapter board, but that won't be possible.
I have some other boards that drove larger 7 seg led ( TPIC6B596 ) It's easy to use too, but i haven't had luck to find something that can drive as many segments as the HT16K33 at higher voltage.

making an adapter board to work with the HT16K33 seems like it might be more trouble than it's worth. and I don't know what else to look for.
I'm willing to work with something that's totally different as long as it can handle Serial or I2c control.

but i haven't had luck to find something that can drive as many segments as the HT16K33 at higher voltage.

That is what the last two posts do. Repeat circuit in first post for each row. Repeat the circuit in second post for each column.

making an adapter board to work with the HT16K33 seems like it might be more trouble than it's worth.

Then probably SOL!