Hello everyone,
My 1st post.
I am new to Arduino and haven't programmed electronics in over 20 years but love a challenge!
I am hoping to build a space ship for my son that is packed with LEDs of various colours, which light up in wonderful patterns. I have done much research but am unsure of which direction to go as I have such a small inherent electronics knowledge.
The spaceship I am designing will have the LEDs grouped in various places e.g. blue for thrusters, red for stripes down the sides and round the body, white for the cockpit etc. I am hoping to be able to programme them in groups to perform different sequences e.g. permanently on or appearing to rotate or light up in a string. My research has shown me shift registers 74HC595, TCL595.., tinyAVRs and many matricised arrays but I don't see if this can be adapted to the non-matrix set up I am aiming for.
The space ship is likely to have 105 LEDs, a proximity sensor to light up some 'landing light' LEDs to act as a reading light (spaceship will be above my sons bed) and a switch to turn the whole thing on.
I would really welcome any advice on the best route or capability of a set up, but in particular:
If I daisy chained 74hc595s can I tell a group of the LEDs to perform a sequence whilst the others are doing something else?
Can I control 105 LEDs from daisy chain 74hc595s?
the wiring isn't too much of an issue as I don't mind soldering up hundreds of wires (as I said I like a challenge).
Are you familiar with WS2812B LEDs? Those and/or APA-106 (compatible protocol, but in through-hole package with frosted surface) might make your life much easier - they're 4-pin RGB LEDs with power, ground, data in, and data out, and you daisy-chain the LEDs together, and use one of the countless libraries available to control them; that single data line allows you to control hundreds of LEDs with one pin on the Arduino. They're available in strips and strings from eBay, as well as panels of various shapes.
I do love me some WS2812BS, the 4 pin package is not especially friendly for hand soldering but they can be gotten online pre-mounted on "heatsink"s that have soldering pads on the bottom for a reasonable price.
A big factor to keep in mind if you do choose the WS2812B or similar is power requirements, your normal average LED is generally listed as a forward current of 20ma, the WS2812Bs are basically 3 LEDs in one package meaning at full white the forward current for each WS2812B should be ~60ma, so for 105 you are looking at a 6.3 Amp power requirement. Certainly doable, plenty of power supplies available for a project like that, just not something you are going to be able to run off of a few AA batteries.
For color changing or patterns probably WS2812B is easiest solution.
For things that do not really require that much flexibility (for instance high brightness white LEDs for landing light/reading light that are either on or off) you could have a group of LEDs controlled by a single pin. An Atmega328 gets you around 20 useable pins, you use 1 pin to run a WS2812B strip, meaning you have plenty left for groups (also some are PWM pins so you can do brightness level adjustment instead of just straight on/off)
Thank you DrAzzy and BH72 I will check these out! I did a quick search which showed them to look expensive in the quantities I may need, but its great to know a way exists if i cant do it on a very small budget.
Maybe a MAX7219 would work. One chip can control 64 individual LED's for turning them on/off and can adjust the brightness of all the LED's at the same time in 15 steps. The only problem might be wiring them as I expect it to turn into a rats nest real quick.
MAX7219 can only drive monochrome LED where NEO pixels are RGB.
MAX cannot dim individual LED's under code just the entire array of LED's in 15 steps, NEO pixel has 255 levels of brightness.