crc

src/main/java/com/rusefi/can/analysis/J1850_SAE_crc8_Calculator.java

@@ -0,0 +1,21 @@
+package com.rusefi.can.analysis;
+
+public class J1850_SAE_crc8_Calculator {
+    byte crc8(byte[] data, int length) {
+        byte crc = 0;
+
+        if (data == null)
+            return 0;
+        crc ^= 0xff;
+        int ptr = 0;
+
+        while (length-- > 0) {
+            crc ^= data[ptr++];
+            for (int k = 0; k < 8; k++)
+                crc = (byte) (((crc & 0x80) != 0) ? (crc << 1) ^ 0x1d : crc << 1);
+        }
+        crc &= 0xff;
+        crc ^= 0xff;
+        return crc;
+    }
+}

src/test/java/com/rusefi/can/analysis/Crc8Test.java

@@ -0,0 +1,14 @@
+package com.rusefi.can.analysis;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class Crc8Test {
+    @Test
+    public void test() {
+        J1850_SAE_crc8_Calculator c = new J1850_SAE_crc8_Calculator();
+
+        assertEquals((byte) 0xfc, c.crc8(new byte[]{0x00, 0x00, 0x00, 0x00, (byte) 0xa0, 0x00, 0x2d}, 7));
+    }
+}