waterproof 8x8 pixel modules, roughly 1m x 1m in size and should be no more than 7cm thick.
based on WS2811 leds for ease
powered by a car/leisure battery
more complex control box that handles animation, text and all sorts as required
plan is to create 6 modules by this time next year.
8 letters, roughly A2 size, construction material will be polycarbonate roofing material such as used in greenhouses, this will be lightweight and diffuse well.
led strip inside letters will be 12V RGB LED strip (the cheap, non-addressable stuff)
Following many issues with controlling 12V strip, I had to re-evaluate the feasibility of it... coupled with some discussions about flexibility, the project has morphed into a series of pixel panels, these will be usable in a domestic environment as well as in a field, using a series of 6 8x8 panels, I will have space for 8 standard letters, and of course, animations.
I knocked together a prototype of 2x2 pixels in an hour and it turned out well, visible indoors, and outdoors at dusk/night, it works rather well.
here we see Mode and Speed/Colour buttons, the screen, brightness knob, all 8 control boards hooked up to small 12v LED strips
as i forgot to put in the pullup resistors on the first version of the board, these have them on the back, along with the (somewhat bodged) power rails, from top down, 5V, data and clock, 12V then the lower one is GND.
view of the top:
again at about 16% brightness to allow a photo to be taken, its much brighter when on full!
close up of the LCD and arduino nano:
currently the backlight only comes on when below about 20% brightness (assuming it would be dark when wanting it dimmer) but think i will put it on all the time.
fiddled about with Kicad but in the end went back to DesignSpark and got it done in about the same time as it took to make a component in Kicad. sent off to OSH Park (https://oshpark.com/orders/UVd3Zd07) to be made.
models for the MOSFETs are not quite right but the holes are the same which is the important thing