0

This is my first Raspberry Pi project that involves an LED ring with button control, and I have some very basic questions.

I am making a halloween costume with a Raspberry Pi and this SparkFun Lumenati 8-Pack LED. I don't really need it to be perfect, and am not too worried about dim LEDs, so my question is, can I power it directly from the Pi's 5v pin and ground? In a tutorial I found, they use a PCA9306 Level Translator Breakout, in this configuration. Should I bite the bullet and buy the breakout?

Additionally, I want to use a portable phone charging pack to power the RPI. It is 5V so I feel like it should work. I would plug it directly into the USB so I don't think I would need a voltage regulator. Thoughts?

Lastly, I'd like to have a button connected to the RPI that cycles the LED ring between 3 modes: flashing blue, flashing green, and flashing red. Should I connect the button to certain GPIO ports?

Thanks so much in advance.

  • Please follow the rule, one question, don't mix multiple questions in one question! – MatsK Oct 24 '17 at 12:31
0

LEDs power supply

Assuming those LEDs are similar to adafruit's dotstar leds, the maximum current is 0.48A (8 leds * 60 mA). According to this answer, you can use the +5V pin and ground to power your leds.

About the level shifter

The APA102C datasheet says that the input high threshold (VIH) is 3.5V (0.7*VDD), and the GPIO from the PI are 3.3V. So without the level shifter, you're out of spec.

Power bank

Running that out of a power bank should work, given the battery pack is rated for at least 5V 2.5A.

Button

Any GPIO should do, but you can have a look here.

About the PI

This is probably not the answer you're looking for, neither a good site for posting it, but an arduino (mini or nano) will probably be easier to program, and will consume less (so your battery pack will last longer).

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.