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NEED HELP PLEASE!! new project

lena_boyd

New Member
Hi there everyone,
I'm new to this site!

I joined because I would love to expand my knowledge when it comes to electronics. :)

Here's my current project, which I would really appreciate any advice for:

I plan to create a flexible LED matrix using WS2812B addressable LED lights.

This is for a visor in a helmet, which will light up - I would love to be able to display words and patterns on the matrix, which would involve coding/finding a code - I would probably use a simple app on my phone through Bluetooth (I've seen videos where people have done this).
all I know is that it'll need a switch, I assume some sort of Bluetooth thing, something to upload the code to and a battery (but i don't know what voltage or anything).

Other than this I have no clue what other components I would need, how I would go about processing the code.

If anyone has any advice I would REALLY appreciate it! Thank you!!!:cool:
 

Pommie

Well-Known Member
Most Helpful Member
Welcome.
You may want to rethink using WS2812's as a reasonable resolution display (say 32x8) would need 256 of them. Each LED can take up to 60mA which will require about 15A at 3.5V (50W). That would flatten a (80Ah) car battery in ~20 hours. Maybe use a display such as this (the 4 digit one).

Mike.
 

rjenkinsgb

Well-Known Member
Most Helpful Member
None of the parts are a problem; you can even buy flexible panels of RGB programmable LEDS:
That is actually rated at 77 Watts at full brightness, so a fraction over 15A at 5V. At low brightness it would take rather less power.

A small MCU such as an Arduino or PIC to control them, plus something like an HC05 bluetooth module to communicate with it, and a big 5V buck converter.

And one of the many "moving message" programs such as this:

As Pommie says, the big problem is the amount of power needed. Even something like a big electric drill battery pack or RC flight pack, 18/20V 5AH would only run it for an hour or two with that type of power consumption.

Using conventional LEDs with a matrix drive would be far more power-efficient, though at the cost of it being a single-colour display.

You could use some MAX7219 LED drivers plus normal LEDs to duplicate something like these, but on a curved base, rather than the moulded LED modules; using high brightness LEDs that could be made very power efficient:
Each IC (or ready made PCB module) will drive an 8x8 array of LEDs:

And this is a bluetooth-linked moving message display project using those MAX7219-controlled LED arrays:

Or several small LCD panels would also work; eg. the common 1.44" 128x128 pixel ones take less power than a single Neopixel type LED.
 

lena_boyd

New Member
None of the parts are a problem; you can even buy flexible panels of RGB programmable LEDS:
That is actually rated at 77 Watts at full brightness, so a fraction over 15A at 5V. At low brightness it would take rather less power.

A small MCU such as an Arduino or PIC to control them, plus something like an HC05 bluetooth module to communicate with it, and a big 5V buck converter.

And one of the many "moving message" programs such as this:

As Pommie says, the big problem is the amount of power needed. Even something like a big electric drill battery pack or RC flight pack, 18/20V 5AH would only run it for an hour or two with that type of power consumption.

Using conventional LEDs with a matrix drive would be far more power-efficient, though at the cost of it being a single-colour display.

You could use some MAX7219 LED drivers plus normal LEDs to duplicate something like these, but on a curved base, rather than the moulded LED modules; using high brightness LEDs that could be made very power efficient:
Each IC (or ready made PCB module) will drive an 8x8 array of LEDs:

And this is a bluetooth-linked moving message display project using those MAX7219-controlled LED arrays:

Or several small LCD panels would also work; eg. the common 1.44" 128x128 pixel ones take less power than a single Neopixel type LED.
thanks so much, this is really helpful!!:))
 

rjenkinsgb

Well-Known Member
Most Helpful Member
Now this is far more practical, though rather more expensive:


The flexible OLED HD displays appear to be readily available on Aliexpress, eg.

They take a full video display via HDMI, so video from any suitable video player or Raspberry Pi etc.

(There is also an 8" version, at around $1100...)
 

Pommie

Well-Known Member
Most Helpful Member
The 8x32 Max7219 displays can be cut into 4 separate units and wired together to give a pseudo curved display. If cost isn't a problem, I'd go with the OLED display.

Mike.
 

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