[SOLVED] new inline skate project

Hallo,

I am looking for a design to attach it on the bottom of my inline skate. a board thats powered from a 3.7V lithium battery, which can be charged from the USB port. preferably as small as possible, 4 by 5 cm (1.5 bij 2 inch). An Arduino-based custom design. 8 separate powerfull RGB LED outputs. And if possible/ unnecessary a mico microphone and waterproof.
Is the idea possible to make? If so, and which equipment do I need to buy? Btw, i know nothing about soldering.
it must seem like a spider with separate RGB LEDs on each leg.
thanks for helping.

I'm doing some guessing here...I think you want to attach LED's to your skates for ground effects.

Do you want your leds to blink?

If not, then this would be pretty simple. Just hook up each LED in series with the battery and resistors. For good measure, you can even add a switch so you can turn the thing off. The resistors simply limit the current passing through the LED's. To figure out the resistor size, look at the LED datasheets and find out what the maximum current is. Choose a round number less than that and use ohms law to V=I*R to guess at a good value for R (the resistor value). If the LED is too dim, make your resistor smaller. If you LED blows up, make your resistor bigger.

If you choose the right color of LED and attach them to the skates in a quality manner, then I'd half to say it would look cool in a dark room. But, don't take my word for it....




If you want flashing LEDS then this will be more work.
If you want to start somewhere simple and inexpensive, try this: https://wild-bohemian.com/electronics/flasher.html
If you want to start somewhere harder and more expensive, try this: https://arduino.cc/en/Tutorial/Blink?from=Tutorial.BlinkingLED

Thank you for replay. it should flicker and change color by arduino codes. I think around 30-40 euros or more for 1 board. take a look at this design: I hope this is not a copyright. **broken link removed** but this one only works with 5v and more

I think you are going to have a hard time getting someone to hand you a board design (for free) given a few vauge specifications. It takes a lot of work to design a board. You need to break this project into baby steps.

The voltage of a rechargeable Lithium cell is 4.2V when fully charged and the LEDs will be bright. The voltage drops as it runs down and the LEDs will get dimmer. The voltage is 3.2V when the battery needs to be disconnected and recharged but the LEDs might not produce any light before that happens.

I have some blue LEDs that are 3.5V when bright and 3.2V when fairly dim.
Hey, without a battery one LED produced 1.5V when in sunlight.

@beeflobill ; you know some steps?
@Audioguru: so i can buy that design from the site, it would work?

I explained why your idea WILL NOT WORK.
The LEDs need more voltage than the battery can produce.

@beeflobill ; you know some steps?

Click to expand...

I have more baby steps than you can shake a stick at. Here are some ideas:

Try hooking up a LED to a battery with a resistor. Measure the voltage across the LED. Measure the voltage across the resistor. Try calculating the current flowing through the LED. Measure the current flowing through the circuit and see if it matches.

Order an arduino board. Find a arduino programming tutorial and work through it. Try hooking up an led to it and see if it works. Write some code to make the LED blink. Does it work? Can the arduino source enough current to drive the LED? I'd assume so, but I could be wrong. Measure how much current the arduino takes with the LED on and off. Does it match your expectations?

Find a voltage source and hook up the arduino board to it. Turn the voltage down and see at what voltage the arduino dies. Does it match the board spec?

Decide how long you want the arduino to stay alive if you hooked it up to a battery. Since you know how much current it takes, and at what voltage it dies a painfull death, you should be able to find a battery that can supply enough current and voltage for the time you need it to. Is the battery small enough to meet your needs? Is the battery too expensive? Have you considered getting a higher voltage battery and then regulating the output voltage if it is too much for the arduino board?