added JBD correct checksum calculation and tests

ai-republic · ai-republic · commit f59159e397c3 · 2025-11-01T13:23:21.000+08:00
diff --git a/bms-jbd-rs485/src/main/java/com/airepublic/bmstoinverter/bms/jbd/rs485/JBDBmsRS485Descriptor.java b/bms-jbd-rs485/src/main/java/com/airepublic/bmstoinverter/bms/jbd/rs485/JBDBmsRS485Descriptor.java
@@ -42,7 +42,7 @@ public Class<? extends BMS> getBMSClass() {
 
     @Override
     public Port createPort(final BMSConfig config) {
-        final Port port = new JSerialCommPort(config.getPortLocator(), config.getBaudRate(), 8, 1, SerialPort.NO_PARITY, new byte[] { (byte) 165 }, FrameDefinition.create("SACLDVO"));
+        final Port port = new JSerialCommPort(config.getPortLocator(), config.getBaudRate(), 8, 1, SerialPort.NO_PARITY, new byte[] { (byte) 0xDD }, FrameDefinition.create("SCOLDVVO"));
         return port;
     }
 
diff --git a/bms-jbd-rs485/src/main/java/com/airepublic/bmstoinverter/bms/jbd/rs485/JBDBmsRS485Processor.java b/bms-jbd-rs485/src/main/java/com/airepublic/bmstoinverter/bms/jbd/rs485/JBDBmsRS485Processor.java
@@ -39,21 +39,12 @@ public class JBDBmsRS485Processor extends BMS {
             return false;
         }
 
-        final int command = buffer.get(1);
-        final int length = buffer.get(3);
-        final byte[] data = new byte[length];
-        buffer.get(data, 4, length);
-
-        // calculate checksum
-        int sum = 0x0000;
-        sum -= (byte) command;
-
-        for (final byte element : data) {
-            sum -= element;
-        }
+        buffer.rewind();
+        final byte[] data = buffer.array();
+        final short checksum = compute(data);
 
         // compare the checksum
-        return buffer.get(length + 4) == (byte) (sum >> 8 & 0xFF) && buffer.get(length + 5) == (byte) (sum & 0xFF);
+        return data[data.length - 3] == (byte) (checksum >> 8 & 0x00FF) && data[data.length - 2] == (byte) (checksum & 0x00FF);
     };
 
     public static class DataEntry {
@@ -94,7 +85,7 @@ public void setData(final ByteBuffer data) {
     }
 
     @Override
-    protected void collectData(final Port port) throws TooManyInvalidFramesException, NoDataAvailableException, IOException {
+    public void collectData(final Port port) throws TooManyInvalidFramesException, NoDataAvailableException, IOException {
         sendMessage(port, 0x03);
         sendMessage(port, 0x04);
         sendMessage(port, 0x05);
@@ -135,8 +126,9 @@ private List<ByteBuffer> sendMessage(final Port port, final int command) throws
                 if (valid) {
                     receiveBuffer.rewind();
                     final int length = receiveBuffer.get(3);
-                    receiveBuffer.position(3);
+                    receiveBuffer.position(4);
                     final byte[] dataBytes = new byte[length];
+                    receiveBuffer.get(dataBytes);
                     final ByteBuffer data = ByteBuffer.wrap(dataBytes).order(ByteOrder.BIG_ENDIAN);
 
                     switch (receiveBuffer.get(1)) {
@@ -151,6 +143,7 @@ private List<ByteBuffer> sendMessage(final Port port, final int command) throws
                         }
                         break;
                         case 0x05: {
+                            readHardwareVersion(pack, data);
                             done = true;
                         }
                         break;
@@ -213,54 +206,73 @@ private List<ByteBuffer> sendMessage(final Port port, final int command) throws
     private void readStatus(final BatteryPack pack, final ByteBuffer data) {
         // total voltage (10mV)
         pack.packVoltage = data.getShort() / 10;
+        LOG.debug("Pack voltage: {} V", pack.packVoltage / 10.0);
         // current (10mAh)
         pack.packCurrent = data.getShort() / 10;
+        LOG.debug("Pack current: {} A", pack.packCurrent / 10.0);
         // remaining capacity (10mAh)
         pack.remainingCapacitymAh = data.getShort() * 10;
+        LOG.debug("Remaining capacity: {} Ah", pack.remainingCapacitymAh / 1000.0);
         // nominal capacity (10mAh)
         pack.ratedCapacitymAh = data.getShort() * 10;
+        LOG.debug("Rated capacity: {} Ah", pack.ratedCapacitymAh / 1000.0);
         // bms cycles
         pack.bmsCycles = data.getShort();
+        LOG.debug("BMS Cycles: {}", pack.bmsCycles);
         // production date (not mapped)
         data.getShort();
         // balancing states
         final int balanceStates = data.getInt();
 
         for (int idx = 0; idx < 32; idx++) {
             pack.cellBalanceState[idx] = BitUtil.bit(balanceStates, idx);
+            LOG.debug("Cell {} balance state: {}", idx + 1, pack.cellBalanceState[idx]);
         }
 
         // protection status
         readAlarms(pack, data.getShort());
         // software version
         final byte sw = data.get();
         pack.softwareVersion = String.format("%02X", sw >> 4) + "." + String.format("%02X", sw & 0x0F);
+        LOG.debug("Software version: {}", pack.softwareVersion);
 
         // remaining SOC (1%)
         pack.packSOC = data.get() * 10;
+        LOG.debug("Pack SOC: {} %", pack.packSOC / 10.0);
 
         final byte mosState = data.get();
         pack.chargeMOSState = BitUtil.bit(mosState, 0);
+        LOG.debug("Charge MOS State: {}", pack.chargeMOSState);
         pack.dischargeMOSState = BitUtil.bit(mosState, 1);
+        LOG.debug("Discharge MOS State: {}", pack.dischargeMOSState);
 
         // number of battery strings
         data.get();
 
         // number of temperature sensors
         pack.numOfTempSensors = data.get();
+        LOG.debug("Number of temperature sensors: {}", pack.numOfTempSensors);
 
-        // temperature
-        pack.tempAverage = 0;
-        for (int i = 0; i < pack.numOfTempSensors; i++) {
-            pack.tempAverage += data.getShort() - 2731;
+        if (pack.numOfTempSensors != 0) {
+            // temperature
+            pack.tempAverage = 0;
+
+            for (int i = 0; i < pack.numOfTempSensors; i++) {
+                pack.tempAverage += data.getShort() - 2731;
+            }
+
+            pack.tempAverage = pack.tempAverage / pack.numOfTempSensors;
+            LOG.debug("Average temperature: {} °C", pack.tempAverage / 10.0);
         }
-        pack.tempAverage = pack.tempAverage / pack.numOfTempSensors;
     }
 
 
     private void readCellVoltages(final BatteryPack pack, final ByteBuffer data) {
-        for (int cellNo = 0; cellNo < data.capacity(); cellNo++) {
+        pack.numberOfCells = data.capacity() / 2;
+
+        for (int cellNo = 0; cellNo < pack.numberOfCells; cellNo++) {
             pack.cellVmV[cellNo] = data.getShort();
+            LOG.debug("Cell {} voltage: {} V", cellNo + 1, pack.cellVmV[cellNo] / 1000.0);
         }
     }
 
@@ -271,6 +283,18 @@ private void readAlarms(final BatteryPack pack, final short short1) {
     }
 
 
+    private void readHardwareVersion(final BatteryPack pack, final ByteBuffer data) {
+        String hardwareVersion = "";
+
+        for (int i = 0; i < data.capacity(); i++) {
+            hardwareVersion += (char) data.get(); // ascii chars
+        }
+
+        pack.hardwareVersion = hardwareVersion;
+        LOG.debug("Hardware version: {}", pack.hardwareVersion);
+    }
+
+
     ByteBuffer prepareSendFrame(final int command, final int length, final byte[] data) {
         final ByteBuffer sendFrame = ByteBuffer.allocate(7 + length).order(ByteOrder.BIG_ENDIAN);
         sendFrame.put((byte) 0xDD); // Start flag
@@ -295,9 +319,35 @@ ByteBuffer prepareSendFrame(final int command, final int length, final byte[] da
     }
 
 
+    public static short compute(final byte[] frame) {
+        if (frame == null || frame.length < 5) {
+            throw new IllegalArgumentException("Invalid frame or index range");
+        }
+
+        short sum = 0;
+        for (int i = 2; i < frame.length - 3; i++) {
+            sum += frame[i] & 0xFF;
+        }
+
+        sum &= 0xFFFF;
+        final int checksum = ~sum + 1 & 0xFFFF;
+
+        return (short) checksum;
+    }
+
+
     public static void main(final String[] args) {
-        final JBDBmsRS485Processor p = new JBDBmsRS485Processor();
-        final ByteBuffer sendFrame = p.prepareSendFrame(0x03, 0, new byte[] {});
-        System.out.println(Port.printBuffer(sendFrame));
+        final byte[] frame = new byte[] {
+                (byte) 0xDD, (byte) 0x03, (byte) 0x00, (byte) 0x28, (byte) 0x15, (byte) 0x84, (byte) 0x03, (byte) 0xA4,
+                (byte) 0xC8, (byte) 0xE3, (byte) 0x80, (byte) 0xE8, (byte) 0x00, (byte) 0x10, (byte) 0x31, (byte) 0x3D,
+                (byte) 0xBA, (byte) 0xAA, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x54, (byte) 0x64,
+                (byte) 0xCB, (byte) 0x10, (byte) 0x04, (byte) 0x0B, (byte) 0x49, (byte) 0x0B, (byte) 0x62, (byte) 0x0B,
+                (byte) 0xFD, (byte) 0x0B, (byte) 0x57, (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x80, (byte) 0xE8,
+                (byte) 0xC8, (byte) 0xE3, (byte) 0x00, (byte) 0x00, (byte) 0xF4, (byte) 0xCE, (byte) 0x77
+        };
+
+        final short checksum = compute(frame);
+        System.out.printf("Calculated checksum: 0x%02X%n", checksum & 0xFFFF);
     }
+
 }
diff --git a/bms-jbd-rs485/src/test/java/com/airepublic/bmstoinverter/jbd/rs485/JBDBmsRS485ProcessorTest.java b/bms-jbd-rs485/src/test/java/com/airepublic/bmstoinverter/jbd/rs485/JBDBmsRS485ProcessorTest.java
@@ -0,0 +1,146 @@
+package com.airepublic.bmstoinverter.jbd.rs485;
+
+import java.io.IOException;
+import java.nio.ByteBuffer;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+import com.airepublic.bmstoinverter.bms.jbd.rs485.JBDBmsRS485Descriptor;
+import com.airepublic.bmstoinverter.bms.jbd.rs485.JBDBmsRS485Processor;
+import com.airepublic.bmstoinverter.core.BMSConfig;
+import com.airepublic.bmstoinverter.core.NoDataAvailableException;
+import com.airepublic.bmstoinverter.core.Port;
+import com.airepublic.bmstoinverter.core.protocol.rs485.FrameDefinition;
+import com.airepublic.bmstoinverter.protocol.rs485.JSerialCommPort;
+import com.fazecast.jSerialComm.SerialPort;
+import com.fazecast.jSerialComm.SerialPortEvent;
+
+public class JBDBmsRS485ProcessorTest {
+    private final static JBDBmsRS485Processor processor = new JBDBmsRS485Processor();
+    private final static JBDBmsRS485Descriptor descriptor = new JBDBmsRS485Descriptor() {
+        @Override
+        public Port createPort(final BMSConfig config) {
+            return port;
+        }
+    };
+
+    private final static BMSConfig bmsConfig = new BMSConfig(1, "port0", 9600, 200, descriptor);
+    private final static JSerialCommPort port = new JSerialCommPort(bmsConfig.getPortLocator(), bmsConfig.getBaudRate(), 8, 1, SerialPort.NO_PARITY, new byte[] { (byte) 0xDD }, FrameDefinition.create("SCOLDVVO")) {
+        @Override
+        public boolean isOpen() {
+            return true;
+        }
+
+
+        @Override
+        public void sendFrame(final ByteBuffer frame) throws IOException {
+            // do nothing
+        }
+
+
+        @Override
+        public void clearBuffers() {
+            // do nothing
+        }
+    };
+    private final SerialPort serialPort = Mockito.mock(SerialPort.class);
+
+    @BeforeAll
+    public static void setupOnce() {
+        processor.initialize(bmsConfig);
+    }
+
+
+    @Test
+    public void testReadFrame03() throws Throwable {
+        final byte[] frame = new byte[] {
+                (byte) 0xDD, 0x03, 0x00, 0x1B, 0x17, 0x00, 0x00, 0x00, 0x02, (byte) 0xD0, 0x03, (byte) 0xE8,
+                0x00, 0x00, 0x20, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x48,
+                0x03, 0x0F, 0x02, 0x0B, 0x76, 0x0B, (byte) 0x82, (byte) 0xFB, (byte) 0xFF, 0x77
+        };
+        final SerialPortEvent event = new SerialPortEvent(serialPort, SerialPort.LISTENING_EVENT_DATA_RECEIVED, frame);
+        port.serialEvent(event);
+
+        // expect exception collecting data
+        Assertions.assertThrowsExactly(NoDataAvailableException.class, () -> {
+            processor.collectData(port);
+        });
+
+        Assertions.assertEquals(588, processor.getBatteryPack(0).packVoltage);
+        Assertions.assertEquals(720, processor.getBatteryPack(0).packSOC);
+        Assertions.assertEquals(209, processor.getBatteryPack(0).tempAverage);
+    }
+
+
+    @Test
+    public void testReadFrame04() throws Throwable {
+        final byte[] frame = new byte[] { (byte) 0xDD, (byte) 0x04, (byte) 0x00, (byte) 0x1E, (byte) 0x0F, (byte) 0x66, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x64, (byte) 0x0F, (byte) 0x3E, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x37, (byte) 0x0F, (byte) 0x5B, (byte) 0x0F, (byte) 0x65, (byte) 0x0F, (byte) 0x3B, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x3C, (byte) 0x0F,
+                (byte) 0x66, (byte) 0x0F, (byte) 0x3D, (byte) 0xF9, (byte) 0xF9, (byte) 0x77 };
+        final SerialPortEvent event = new SerialPortEvent(serialPort, SerialPort.LISTENING_EVENT_DATA_RECEIVED, frame);
+        port.serialEvent(event);
+
+        // expect exception collecting data
+        Assertions.assertThrowsExactly(NoDataAvailableException.class, () -> {
+            processor.collectData(port);
+        });
+
+        Assertions.assertEquals(3900, processor.getBatteryPack(0).cellVmV[12]);
+    }
+
+
+    @Test
+    public void testReadFrame05() throws Throwable {
+        final byte[] frame = new byte[] { (byte) 0xDD, (byte) 0x05, (byte) 0x00, (byte) 0x0A, (byte) 0x30, (byte) 0x31, (byte) 0x32, (byte) 0x33, (byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37, (byte) 0x38, (byte) 0x39, (byte) 0xFD, (byte) 0xE9, (byte) 0x77 };
+        final SerialPortEvent event = new SerialPortEvent(serialPort, SerialPort.LISTENING_EVENT_DATA_RECEIVED, frame);
+        port.serialEvent(event);
+
+        // expect exception collecting data
+        Assertions.assertThrowsExactly(NoDataAvailableException.class, () -> {
+            processor.collectData(port);
+        });
+
+        Assertions.assertEquals("0123456789", processor.getBatteryPack(0).hardwareVersion);
+    }
+
+
+    @Test
+    public void testChecksum03() {
+        final byte[] frame = new byte[] {
+                (byte) 0xDD, 0x03, 0x00, 0x1B, 0x17, 0x00, 0x00, 0x00, 0x02, (byte) 0xD0, 0x03, (byte) 0xE8,
+                0x00, 0x00, 0x20, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x48,
+                0x03, 0x0F, 0x02, 0x0B, 0x76, 0x0B, (byte) 0x82, (byte) 0xFB, (byte) 0xFF, 0x77
+        };
+
+        final short checksum = JBDBmsRS485Processor.compute(frame);
+
+        System.out.printf("Calculated checksum = 0x%04X%n", checksum);
+        Assertions.assertEquals((short) 0xFBFF, checksum);
+    }
+
+
+    @Test
+    public void testChecksum04() {
+        final byte[] frame = new byte[] { (byte) 0xDD, (byte) 0x04, (byte) 0x00, (byte) 0x1E, (byte) 0x0F, (byte) 0x66, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x64, (byte) 0x0F, (byte) 0x3E, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x37, (byte) 0x0F, (byte) 0x5B, (byte) 0x0F, (byte) 0x65, (byte) 0x0F, (byte) 0x3B, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x63, (byte) 0x0F, (byte) 0x3C, (byte) 0x0F,
+                (byte) 0x66, (byte) 0x0F, (byte) 0x3D, (byte) 0xF9, (byte) 0xF9, (byte) 0x77 };
+
+        final short checksum = JBDBmsRS485Processor.compute(frame);
+
+        System.out.printf("Calculated checksum = 0x%04X%n", checksum);
+        Assertions.assertEquals((short) 0xF9F9, checksum);
+    }
+
+
+    @Test
+    public void testChecksum05() {
+        final byte[] frame = new byte[] { (byte) 0xDD, (byte) 0x05, (byte) 0x00, (byte) 0x0A, (byte) 0x30, (byte) 0x31, (byte) 0x32, (byte) 0x33, (byte) 0x34, (byte) 0x35, (byte) 0x36, (byte) 0x37, (byte) 0x38, (byte) 0x39, (byte) 0xFD, (byte) 0xE9, (byte) 0x77 };
+
+        final short checksum = JBDBmsRS485Processor.compute(frame);
+
+        System.out.printf("Calculated checksum = 0x%04X%n", checksum);
+        Assertions.assertEquals((short) 0xFDE9, checksum);
+    }
+
+}

Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ public Class<? extends BMS> getBMSClass() {`
`42`	`42`
`43`	`43`	`@Override`
`44`	`44`	`public Port createPort(final BMSConfig config) {`
`45`		`- final Port port = new JSerialCommPort(config.getPortLocator(), config.getBaudRate(), 8, 1, SerialPort.NO_PARITY, new byte[] { (byte) 165 }, FrameDefinition.create("SACLDVO"));`
	`45`	`+ final Port port = new JSerialCommPort(config.getPortLocator(), config.getBaudRate(), 8, 1, SerialPort.NO_PARITY, new byte[] { (byte) 0xDD }, FrameDefinition.create("SCOLDVVO"));`
`46`	`46`	`return port;`
`47`	`47`	`}`
`48`	`48`