only: https://www.youtube.com/watch?v=T6JFTmQCFHg

firmware/hw_layer/drivers/can/can_msg_tx.cpp

@@ -113,6 +113,7 @@ void CanTxMessage::setBus(size_t bus) {
 	busIndex = bus;
 }
 
+// LSB Little-endian System, "Intel"
 void CanTxMessage::setShortValue(uint16_t value, size_t offset) {
 	m_frame.data8[offset] = value & 0xFF;
 	m_frame.data8[offset + 1] = value >> 8;

firmware/hw_layer/drivers/can/can_msg_tx.h

@@ -53,7 +53,7 @@ public:
 	uint8_t& operator[](size_t);
 
 	/**
-	 * @brief Write a 16-bit short value to the buffer. Note: this writes in big endian byte order.
+	 * @brief Write a 16-bit short value to the buffer. Note: this writes in little endian byte order.
 	 */
 	void setShortValue(uint16_t value, size_t offset);
 

java_console/shared_io/src/test/java/com/rusefi/core/FileUtilTest.java

@@ -0,0 +1,31 @@
+package com.rusefi.core;
+
+import org.junit.jupiter.api.Test;
+
+import java.nio.ByteBuffer;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class FileUtilTest {
+
+    static void setShortValue(byte[] data8, int value, int offset) {
+        data8[offset] = (byte) (value & 0xFF);
+        data8[offset + 1] = (byte) (value >> 8);
+    }
+
+    @Test
+    public void damnItWhichOneIsLittleEndian() {
+        byte[] testArrayForLittleEndianByteBuffer = new byte[2];
+        // LSB Little-endian System, "Intel"
+        ByteBuffer littleEndianBuffer = FileUtil.littleEndianWrap(testArrayForLittleEndianByteBuffer, 0, 2);
+        short testValue = 0x1122;
+        littleEndianBuffer.putShort(testValue);
+        assertEquals(testArrayForLittleEndianByteBuffer[0], 0x22);
+
+        byte[] testArrayForJavaCodeWhichMimicsCanTxMessageSetShortValue = new byte[2];
+        setShortValue(testArrayForJavaCodeWhichMimicsCanTxMessageSetShortValue, testValue, 0);
+
+        assertEquals(testArrayForJavaCodeWhichMimicsCanTxMessageSetShortValue[0], 0x22);
+        assertEquals(testArrayForJavaCodeWhichMimicsCanTxMessageSetShortValue[1], testArrayForLittleEndianByteBuffer[1]);
+    }
+}