LED Strip Voltages?

VEX V5 General Discussion Technical Discussion
#1

Hello, I am have competition tomorrow and recently added a 9 inch strip of blue LEDs that i got from amazon (link below) and was wondering if I plugged it into a Sensor port on the Cortex that I had already initialized for an LED, would it work? I have previously just been powering the strip off a spare 9v on the Robot but that isn’t legal for competition. Although it sounds like a stupid question, I don’t want to try it and then the strip shorts out my Cortex, since we have a competition tomorrow. I would love it if anyone could provide me with any personal experience that they acquired.

link to where i bought them:

Thanks! :slight_smile:

#2

Someone can correct me if I’m wrong, but I believe 12V is much too high for the sensor ports and will draw a lot of current

#3

Yes, sensor ports output 5V.

#4

if the current is too much for a simple 5V-12V transformer i suggest getting a 12V step up/step down regulator and connect it directly to the battery through a power expander port

#5

Um, I’m not saying it’s illegal, and I know it’s a non-functional decoration, but you might want to check this out.
https://vexforum.com/t/vex-u-battery-bump-up/28431/1

#6

It says clearly they were bumping from the battery to the cortex… nothing to do with decoration, you would legit get banned from worlds if you were caught using it in HS

#7

I had this idea last year and posted the question and it was not allowed sadly… even just for decorative lights :frowning:
https://vexforum.com/t/answered-voltage-converter-for-led-lights/27976/1

#8

I would suggest that you get a new light strip, like the one we use. If you have any questions about how to set them up, I explain here.

#9

These LED strips from Adafruit are 5V and RGB. I’m in the middle of porting the code to RobotC but you would only be able to about 10 inches max due to power draw. Ill post a link to the code when I get it finished up and tested.

#10

looks closer to around 30 inches max according to the page its 0.05 amps per inch when made full white, normally 0.025 amps per inch with colors

#11

Keep in mind that these can only be controlled by a processor/microcontroller that is 8MHz. I don’t think the Cortex is that fast.

#12

The cortex is 90 MIPS, so it could technically drive that, but you are forced to do precise timing bit-banging it would slow down everything a bit.

I would definitely suggest using an 12c based led strip instead

#13