added first code for OBD2 via CAN and K-Line

Software/src/obd2_kline.cpp

@@ -0,0 +1,74 @@
+#include "obd2_kline.h"
+
+// === Konstante für Anfrageintervalle ===
+#define OBD2_QUERY_INTERVAL 500 // alle 500 ms neue Anfrage
+
+// === Private Variablen ===
+static Stream *klineSerial = nullptr;
+static uint32_t lastQueryTime = 0;
+static uint32_t lastRecvTime = 0;
+static uint32_t lastSpeedMMperSec = 0;
+
+// === Slow Init nach ISO9141-2 ===
+void OBD2_KLine_SlowInit()
+{
+    pinMode(1, OUTPUT); // TXD-Pin (z.B. D1)
+    digitalWrite(1, HIGH);
+    delay(3000);
+
+    digitalWrite(1, LOW);
+    delay(200); // 200ms
+    digitalWrite(1, HIGH);
+    delay(400); // 400ms
+    digitalWrite(1, LOW);
+    delay(400); // 400ms
+    digitalWrite(1, HIGH);
+    delay(200); // 200ms
+
+    // zurück auf Serialbetrieb
+    pinMode(1, INPUT);
+    delay(300);
+}
+
+// === Initialisierung ===
+void Init_OBD2_KLine(Stream &serial)
+{
+    klineSerial = &serial;
+    OBD2_KLine_SlowInit();
+    delay(100);
+
+    // Sende 01 0D (Vehicle Speed)
+    byte speedRequest[] = {0x68, 0x6A, 0xF1, 0x01, 0x0D}; // OBD2 PID-Request
+    klineSerial->write(speedRequest, sizeof(speedRequest));
+}
+
+// === Geschwindigkeit abfragen ===
+uint32_t Process_OBD2_KLine_Speed()
+{
+    if (!klineSerial || (millis() - lastQueryTime < OBD2_QUERY_INTERVAL)) return 0;
+
+    byte req[] = {0x68, 0x6A, 0xF1, 0x01, 0x0D};
+    klineSerial->write(req, sizeof(req));
+    lastQueryTime = millis();
+
+    uint8_t buf[16];
+    size_t len = klineSerial->readBytes(buf, sizeof(buf));
+    for (size_t i = 0; i < len - 2; ++i)
+    {
+        if (buf[i] == 0x48 && buf[i + 1] == 0x6B && buf[i + 2] == 0x10)
+        {
+            if (buf[i + 3] == 0x41 && buf[i + 4] == 0x0D)
+            {
+                uint8_t speed_kmh = buf[i + 5];
+                uint32_t speed_mm_per_sec = (uint32_t)speed_kmh * 1000000 / 3600;
+                uint32_t dt = millis() - lastRecvTime;
+                lastRecvTime = millis();
+                lastSpeedMMperSec = speed_mm_per_sec;
+
+                return (speed_mm_per_sec * dt) / 1000;
+            }
+        }
+    }
+
+    return 0;
+}