ESP32s3: Migrate variants to new structure (#7343)

variants/esp32s3/heltec_vision_master_e213/einkDetect.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "configuration.h"
+
+enum class EInkDetectionResult : uint8_t {
+    LCMEN213EFC1 = 0, // Initial version
+    E0213A367 = 1,    // E213 PCB marked V1.1 (Mid 2025)
+};
+
+EInkDetectionResult detectEInk()
+{
+    // Test 1: Logic of BUSY pin
+
+    // Determines controller IC manufacturer
+    // Fitipower: busy when LOW
+    // Solomon Systech: busy when HIGH
+
+    // Force display BUSY by holding reset pin active
+    pinMode(PIN_EINK_RES, OUTPUT);
+    digitalWrite(PIN_EINK_RES, LOW);
+
+    delay(10);
+
+    // Read whether pin is HIGH or LOW while busy
+    pinMode(PIN_EINK_BUSY, INPUT);
+    bool busyLogic = digitalRead(PIN_EINK_BUSY);
+
+    // Test complete. Release pin
+    pinMode(PIN_EINK_RES, INPUT);
+
+    if (busyLogic == LOW)
+        return EInkDetectionResult::LCMEN213EFC1;
+    else // busy HIGH
+        return EInkDetectionResult::E0213A367;
+}