Ini
[env:esp32-s3-devkitc-1]
platform = espressif32
board = esp32-s3-devkitc-1
framework = arduino
monitor_speed = 115200
build_flags =
  -DARDUINO_USB_MODE=1
  -DARDUINO_USB_CDC_ON_BOOT=1

Cpp
#include <Arduino.h>

#define CLK_SHARED_PIN 21
static const uint8_t DATA_PINS[8] = {4, 5, 6, 7, 15, 16, 17, 18};

void pulseClock(uint16_t cycles, uint32_t halfPeriodUs = 2) {
  for (uint16_t i = 0; i < cycles; i++) {
    digitalWrite(CLK_SHARED_PIN, HIGH);
    delayMicroseconds(halfPeriodUs);
    digitalWrite(CLK_SHARED_PIN, LOW);
    delayMicroseconds(halfPeriodUs);
  }
}

void setAllData(bool state) {
  for (uint8_t i = 0; i < 8; i++) {
    digitalWrite(DATA_PINS[i], state ? HIGH : LOW);
  }
}

void setup() {
  Serial.begin(115200);
  delay(500);

  pinMode(CLK_SHARED_PIN, OUTPUT);
  digitalWrite(CLK_SHARED_PIN, LOW);

  for (uint8_t i = 0; i < 8; i++) {
    pinMode(DATA_PINS[i], OUTPUT);
    digitalWrite(DATA_PINS[i], LOW);
  }

  Serial.println("ESP32-S3 multi-port DATA + shared CLK test starting");
}

void loop() {
  for (uint8_t ch = 0; ch < 8; ch++) {
    setAllData(false);
    digitalWrite(DATA_PINS[ch], HIGH);
    pulseClock(16);
    Serial.printf("Pulsed channel %u DATA with shared CLK\n", ch + 1);
    delay(250);
  }

  setAllData(true);
  pulseClock(32);
  delay(500);
  setAllData(false);
  delay(500);
}

Bash
pio run
pio run -t upload
pio device monitor

• First test with no external LED strips attached.
• Probe U2/U3 outputs to confirm 5V logic after level shifting.
• For APA102-style LEDs, adapt firmware to clock DATA and CLK together.
• For WS2812B/SK6812, use DATA pins only and leave CLK pins unused at the cable.