Hi,
I’m new to Arduino and I’m working on a wearable 12V LED strip project. I'm a mechanical engineer/designer and so have some experience of electronics but my knowledge is more than a bit rusty.
Background to Project:
A wearable battery powered light-up costume for professional theatrical use by someone else.
I'm hoping to use between seven and ten sections of LED strip, each around 1metre long. It is single-color 12V SMD3528 LED strip (non-addressable). It has 60 x 0.08W LEDs per metre. i.e 4.8W, 0.4A per metre.
I just want each full 1m section to switch on and off in sequence (or a chasing pattern) at an absolute max of maybe 5 or 10 Hz. I don't think I need to do any PWM initially- the sections don't need to be on at the same time and I'm assuming I can find a battery that can provide 0.5-1A at 12V. It would be good to be able to have it all light up together at some points in the sequence but it looks like this would be difficult in terms of the current draw so I'm happy if this is not doable.
It only needs to run for around 10-20 minutes per battery charge.
The electronics and battery need to be as small as possible. I'll probably design a custom housing for the whole system.
The Problem:
It needs to be durable and safe. I'm slightly concerned about excessive heating and/or electric shocks. I like the idea of a small self contained arduino shield that doesn’t require me to design/build a handmade PCB with mosfets. I would be more comfortable with an off-the-shelf solution initially.
Some options I've found, both from Sparkfun:
-
Power Driver Shield Kit
SparkFun Power Driver Shield Kit - DEV-10618 - SparkFun Electronics
This looks like a simple MOSFET kit but it only has 6 outputs which is not enough for this application. It also uses the non SMD mosfets which are very tall. I don't know if these outputs could be easily multiplexed (?)to give me more? -
4x4 Driver Shield
https://www.sparkfun.com/products/10256?
- "The 4x4 Driver Shield is designed to enable users to switch DC loads up to 5A at up to 30V."
- "Uses only digital pins 7, 8, 11, and 13, leaving all serial, PWM, and analog input lines free"
This sounds great, and its a good size but it's seems more designed for motors and solenoids etc. I'm wondering if I would have problems trying to run the LED strips from these outputs at the frequencies I'm hoping for?
What I'm trying to do seems to be a very common use for arduino so I'm suprised that I can't find more options for readymade high power shields. I can't see any references to people using motor-type shields for powering LEDs.
Both of the options above work with larger sized Arduino boards, but anything suitable that might work with a smaller mini pro /lillypad type board would be even better.
Apologies for the rambling question, but I have been trying to research this and am really unsure. Any help, thoughts or other options would be very much appreciated.
Many thanks,
Barry.
p.s For power source I'm currently looking at high capacity LiPo R/C batteries, but this might be a topic for another day...