Flashing the ESP32-S3 DevKitC RGB LED

[smhodge42]

I presume most of us are like me that when faced with a new microcontroller, we like to use the LED equivalent of "hello world". The pyboard has built-in LED's and I always design one into any custom PCB design, programmed in either uPython or C++. Well, the built-in RBG LED on the new-to-me ESP32-S3-DevKitC-1 board stumped me, having never dealt with an addressable LED before. Plug a fresh-from-the-factory board into power and the RGB LED flashes, so I knew it must be possible. But that code vanished the instant I upgraded the firmware.

It took me a couple of days to figure out the uPython code to do it, largely because I could not find anything on the Internet -- or for that matter in Micropython Documents -- on exactly how to do this supposedly simple task (as a newbie to this board). It retrospect it is pretty simple after you realize/learn that the key is the "NeoPixel" class. I'm posting the code here so that it might save others the same trouble. The code endlessly flashes Red-Green-Blue, each color every second. Presumably the code will work on any ESP32-xx DevKit board with an addressable LED and a uPython port, such as the S2, C3 or C6 DevKits.

from machine import Pin
from time import sleep
from neopixel import NeoPixel
pin = Pin(48, Pin.OUT)                          # Pin number for v1 of the above DevKitC, use pin 38 for v1.1
np = NeoPixel(pin, 1)                            # "1" = one RGB led on the "led bus"
while (True):
    np[0] = (255,0,0)
    np.write()
    sleep(1)
    np[0] = (0,255,0)
    np.write()
    sleep(1)
    np[0] = (0,0,255)
    np.write()
    sleep(1)

[wilsonfleite]

Thanks for share!

[WolleKette]

The board is available in a version with Micro-USB and one with USB-C ports. I'm pretty sure I was able to get the LED to flash with a board (Micro USB version) some time ago.
But now I'm using a USB-C board and the example doesn't work here. Neither on GPIO 38 nor on pin 48.

Does anyone have an idea what the problem could be?

[WolleKette]

I found the solution in a arduino forum here. You have to close the RGB-named solder bridge next to the LED on the board.

[Mstrman4]

thanks I looked for it a lot ❤️❤️🗿

[bidrohini]

Thanks for sharing.

[nex0ma]

esp32-c3-mini with dual USB:

rgb = Pin(8,1)
np = NeoPixel(rgb,1)