Electronics > Beginners
Time to get my feet wet Making an RGB led Heart necklace (with heart shaped pcb)
<< < (3/4) > >>
Ian.M:
That depends - its already well on the way to becoming the sort of obnoxiously large 'bling' that 95% of women wouldn't be caught dead wearing, and now you want to further encumber it with a pre-built MCU board!

An Arduino or similar MCU board is great when you are prototyping something like this but should *NEVER* be part of any space or unit cost constrained final design unless you have done the design work to prove that using a bare MCU wont make it smaller or cheaper.
Nitrousoxide:

--- Quote from: Astaldoath on April 14, 2018, 04:25:12 am ---So do you guys think its smarter or better to go with a prebuilt board to do all the led driving or should I look at building the driving and such in to the pcb to make it cheaper, cause some of the boards that can drive leds and are programmable cost 5-20 dollars

--- End quote ---

IMHO. Go all out, design every aspect of the board. You will get a sense of achievement and it is well worth it as you also learn a LOT from the design and layout process.

My guess is that you'd only need to layout the microcontroller (and supporting components), buck/boost converter and LEDs.
Astaldoath:
ok since i didnt take electrical engineering are there any good books I could learn from? Ive been watching as much as I can online but people dont exactly explain what this does or why, i get the basics ohms, resistance, capacitance, why you need a diodes for reverse feedback stuff like that. I mean Im sure I could calculate how much power i need for the LEDs I just dont know how to build a buck.boost converter or if they are built in to a micro, i was thinking of using the same atmel as an arduino mega 2560. Im not too firmiliar with what micros are good for what yet, ive been trying to look up LED driver chips when ever i feel good enough.


Plus i need to learn how to layout a PCB for someone to make for me with PCB design software and I have 0% experience in that. So ive been looking for friends that know how to use various CAD programs. I thought everything built in to my piece would be more cost effective also. These arent meant to be jewelry, they are meant for kids or people who wanna wear one to a party or somethin.
Audioguru:
Each LED has red, green and blue. The max current of each color is 18mA isn't it? Then all three colors at the highest PWM brightness is 54mA.
Nitrousoxide:

--- Quote from: Astaldoath on April 18, 2018, 09:18:27 pm ---ok since i didnt take electrical engineering are there any good books I could learn from?
...
I just dont know how to build a buck/boost converter or if they are built in to a micro,
...
i was thinking of using the same atmel as an arduino mega 2560. Im not too firmiliar with what micros are good for what yet
...
Plus i need to learn how to layout a PCB for someone to make for me with PCB design software and I have 0% experience in that.

--- End quote ---

A lot of people recommend 'The Art of Electronics', a big book, but a good all-rounder book. If you want a textbook that is more specific to certain disciplines, I will gladly advise.

As for the buck and boost converter. Texas Instruments has an online calculator applet, named web bench which will do all the work in designing a buck/boost converter.
And yes, some microcontrollers may have built-in converters (ex. MSP432Pxx), however, they are NOT to be externally loaded and are ONLY for providing core voltages for the processor. (you wouldn't even be able to pull anywhere near the amount of current out of the internal converter anyway). Most microcontrollers operate in LDO mode anyway, but switching mode will save you some power consumption, would it be a significant amount to warrant the implementation? I don't know, depends on the current draw of the rest of your system.

Again to pick a micro you need to further specify your requirements, i.e. Power consumption, IO, peripherals, development environment.  Digikey or other sites with parametric searches can help you narrow down component choice.

As for PCB software, you choose and you learn. Even at university level that is how it's done. If you want the ducks guts/rolls royce of CAD/CAE programs, go for Altium Designer. Or you can go for their much cheaper alternative, Circuit maker. Theres also eagle, kicad, the list goes on.

Cost effective would be to roll everything on your own. No use of modules. But then again, some people argue the cost of time is more valuable than other tangibles.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod