Small led matrix display with high pixel density and(or) smaller gaps between pixels?

CuriousOne

Hello.

I want to build a simple wearable device, for which I need 7x5 led array to display info I need. It should be as small as possible and look as cute as possible

The problem with available 5x7 dot matrix leds is that either their "pixels" are huge, say 1-2mm in diameter, they are round and have large gaps between pixels, so it is hard to establish a solid image, or they might have smaller "pixels" such as LTP-305G pictured in attachment, but distance between pixels is still huge and they are again round.

Any ideas/models?

WBA Consulting

You could always feed the light from the LEDs through small diameter light pipe material that is bundled together. An idea that passed through my head a short time ago was to pipe light from 36 RGB LEDs through some light pipe from Sparkfun into a 6 x 6 grid that would hold the pipe spaced 4mm in X and Y. Effectively, it would end up being a ~1 square inch (24mm), 36 pixel, "full" color display.

Sparkfun Light Pipe: https://www.sparkfun.com/products/10694

Found some smaller diameter light pipe to make a tighter display on eBay at a better price:
http://www.ebay.com/itm/10-3m-1-5mm-optical-fiber-ESKA-CK-60-fibre-optic-lighting-light-pipe-Mitsubishi-/261698416671?pt=LH_DefaultDomain_0&hash=item3cee70f01f

CuriousOne

Yes but complete device still be huge
Sure, there are oled displays, but they are all fancy, with SPI/I2C etc etc to play around, led matrix is dead simple solution

kwinn

Have you looked at the oled display modules like the one below?

http://www.dx.com/p/0-96-128x64-i2c-interface-white-color-oled-display-module-for-arduino-avr-arm-pic-346540?tc=CAD&gclid=CMGMzvOrh8MCFQotaQodLAsA-Q

I know you want simple, but I2C is very easy to deal with, imo simpler than multiplexing a 5x7 led matrix, and is ready to use. This one is much higher resolution than 5x7 but there are other choices available.

CuriousOne

No matter how hard I've tried, I was never able to make work ANY I2C device with BS2, whenever it was RTC, EEPROM, SHT21 or whatsoever.

Ron Czapala

Check this square pixel display http://www.adafruit.com/products/902

It is I2C though

or maybe this one http://www.adafruit.com/products/458

kwinn

CuriousOne wrote: »

No matter how hard I've tried, I was never able to make work ANY I2C device with BS2, whenever it was RTC, EEPROM, SHT21 or whatsoever.

I have not used the Basic Stamp at all, but I have used the propeller for I2C and multiplexing led displays with no issues. For sure either one of the displays Ron posted will work with the propeller. Time to move up?

Duane Degn

Check out this thread about some small displays

These little OLED displays work great with the Prop.

Here's one in an aluminum wallet.



And another powered from a Prop's I/O pin.



The display is plugged directly into the QuickStart's I/O pins.

These displays were $5. I do have them configured in SPI mode. I had trouble using them in I2C mode.

wass

Ron Czapala wrote: »

Check this square pixel display http://www.adafruit.com/products/902
It is I2C though

or maybe this one http://www.adafruit.com/products/458

Or just red for a lot less money:

https://www.futurlec.com/LED/LEDMS88Rpr.shtml

CuriousOne

Spin and C in general (in my opinion) is language with silly syntax, bogus statements and idiotic code formatting. So instead of going propeller, I went picbasic pro.

Yes that red square matrix is great, but pixels are huge - 3x3mm each. If it was at least 1x1mm....

wass

CuriousOne wrote: »

Spin and C in general (in my opinion) is language with silly syntax, bogus statements and idiotic code formatting. So instead of going propeller, I went picbasic pro.

Yes that red square matrix is great, but pixels are huge - 3x3mm each. If it was at least 1x1mm....

That would be nice, but I can't find that anywhere. Here's a smaller one but has closely packed rounds 1.9mm LED's:

http://www.ebay.com/itm/5-pcs-LED-Display-Dot-Matrix-Common-Anode-Red-1-9mm-8x8-20x20mm-/330738177797?pt=LH_DefaultDomain_0&hash=item4d01881705

Still, they must be made as this watch uses one.

http://www.ebay.com/itm/Personalized-Signature-3D-Pedometer-Smart-Watch-8GB-Flash-Drive-LED-Display-/251787080809?pt=LH_DefaultDomain_0&hash=item3a9fadf469

Maybe buy one and see if it's hackable, it looks to be a 11 x 7.matrix.

David Betz

CuriousOne wrote: »

Spin and C in general (in my opinion) is language with silly syntax, bogus statements and idiotic code formatting. So instead of going propeller, I went picbasic pro.

Yes that red square matrix is great, but pixels are huge - 3x3mm each. If it was at least 1x1mm....

If you like Basic syntax, did you consider using Bean's PropBasic? I believe it is quite fast, faster than Spin and maybe faster than C as well. I'm sure it can handle i2c.

CuriousOne

Yes I've checked propbasic, but it makes no huge advantages of using propeller.
In theory, a lot of languages can handle I2C, but it does not worked in my case.

For the leds, I have the 5x7 matrix using these 1.9mm leds, but they are still round and huge

For the watch display, I've bought similarily looking watch, hoping to salvage display from it. It uses small, caseless led chips, directly soldered to pcb, and enclosed in plastic divider, which forms "pixel"

CuriousOne

This one looks nice, but it is still huge:

http://www.ebay.com/itm/5x7-Square-LED-Dot-Matrix-Display-/121446723816?pt=LH_DefaultDomain_0&hash=item1c46c9f0e8

Compare to dimensions of LTP-305G, which I'm using currently:

http://www.digikey.com/product-detail/en/LTP-305G/160-1001-5-ND/121279