How do i tell a USB port that something is plugged in?

Hello All! I'm currently putting some LED's under my Electric Longboard, i had the idea because i have some left over WS2812B strips after putting Indicators on my bike helmet!

I Noticed my longboard has a built in 5V system as it has a USB port that outputs 5v at 2.1a, so i took it apart and accessed the pins on the PCB that go to the usb port, and then put an LED between the 5v and ground (for visual verification) and proceeded to press the power button to turn on the USB port. The LED turned on (Yay!) but the LCD screen with battery percentage & input/output voltages didn't indicate anything being used (which makes sense as i didn't have anything on the data pins) i remained hopeful, and then 3 seconds later it turned off... So i plugged my Phone to the USB port and used a multimeter to check the data pins, with GND on the GND pin and positive on Data+ i could see there was 0.93v going through it, i then put the positive on Data- and it was the same result.

I'm not great with all this stuff, so i'm wondering if i need to send a specific signal or just 1v down the data pins to make the board think i have a phone plugged in, thus keeping power output going to to the LED.

unfortunately it transforms the 36v from the battery to 5v somewhere on the PCB and i'm not exactly sure where. i also cant find a constant 5v supply anywhere on the PCB.

I have also tried plugging the Arduino into the USB port via a Mini USB cable, however the arduino doesn't send out an appropriate signal either as the longboard doesn't recognise anything in the USB port.

Thank you for any answers!
-Seamus

Sounds like fun, do not let this scare you off, however starting out new with USB can be quite daunting. The USB 2.0 specification at 650 pages long, the USB 3.0 is longer. There is more then connecting two wires to get 5 Volts out. A good source of information is: USB in a NutShell - Chapter 1 - Introduction You will find there are USB Class Standards such as the HID Class Specification which details the common operation of devices (keyboards, mice etc) falling under the HID (Human Interface Devices) Class - only another 97 pages. If you are designing a USB Host, then you have three Host Controller Interface Standards to choose from. None of these are detailed in the USB 2.0 Spec.

gilshultz:
Sounds like fun, do not let this scare you off, however starting out new with USB can be quite daunting. The USB 2.0 specification at 650 pages long, the USB 3.0 is longer. There is more then connecting two wires to get 5 Volts out. A good source of information is: USB in a NutShell - Chapter 1 - Introduction You will find there are USB Class Standards such as the HID Class Specification which details the common operation of devices (keyboards, mice etc) falling under the HID (Human Interface Devices) Class - only another 97 pages. If you are designing a USB Host, then you have three Host Controller Interface Standards to choose from. None of these are detailed in the USB 2.0 Spec.

Thanks for the Reply! I didn't realise what i was getting myself in to! :sweat_smile: i'll look through the documentation and get back to you if i get it working! :slight_smile:

Update: After quite a while of pulling my hair out, i took a bit of a break... and all of a sudden after cleaning my desk i realised my phone power banks don't power the arduino, so i searched up ''powering arduino with power bank" and the answer was infront of my eyes!!!

The 2 power banks i have & Skateboard have a low current limit, so when i was just plugging the nano/LED in they weren't drawing enough current. So i decided i would whack an LED strip on just the 5v output of the nano with a 400mah limit and tried plugging it in with the strip attached.... BOOM!!! Power bank stayed on, then i tried with the skateboard, BOOM!!! Worked perfectly! I'll try getting the power from the back of the USB port now and attach the arduino w/ strip to it and see if it works. (Wooooo)