diff --git a/src/test/Makefile b/src/test/Makefile
index 2620be68da..eb3390550c 100644
--- a/src/test/Makefile
+++ b/src/test/Makefile
@@ -842,6 +842,30 @@ $(OBJECT_DIR)/rx_ibus_unittest : \
 
 	$(CXX) $(CXX_FLAGS) $(PG_FLAGS) $^ -o $(OBJECT_DIR)/$@
 
+
+$(OBJECT_DIR)/telemetry/ibus.o : \
+	$(USER_DIR)/telemetry/ibus.c \
+	$(USER_DIR)/telemetry/ibus.h \
+	$(GTEST_HEADERS)
+
+	@mkdir -p $(dir $@)
+	$(CC) $(C_FLAGS) $(TEST_CFLAGS) -c $(USER_DIR)/telemetry/ibus.c -o $@
+
+$(OBJECT_DIR)/telemetry_ibus_unittest.o : \
+	$(TEST_DIR)/telemetry_ibus_unittest.cc \
+	$(GTEST_HEADERS)
+
+	@mkdir -p $(dir $@)
+	$(CXX) $(CXX_FLAGS) $(TEST_CFLAGS) -c $(TEST_DIR)/telemetry_ibus_unittest.cc -o $@
+
+$(OBJECT_DIR)/telemetry_ibus_unittest : \
+	$(OBJECT_DIR)/telemetry_ibus_unittest.o \
+	$(OBJECT_DIR)/telemetry/ibus.o \
+	$(OBJECT_DIR)/gtest_main.a
+
+	$(CXX) $(CXX_FLAGS) $(PG_FLAGS) $^ -o $(OBJECT_DIR)/$@
+
+
 ## test        : Build and run the Unit Tests
 test: $(TESTS:%=test-%)
 
diff --git a/src/test/unit/telemetry_ibus_unittest.cc b/src/test/unit/telemetry_ibus_unittest.cc
new file mode 100644
index 0000000000..4d0ce9eba5
--- /dev/null
+++ b/src/test/unit/telemetry_ibus_unittest.cc
@@ -0,0 +1,489 @@
+/*
+ * This file is part of Cleanflight.
+ *
+ * Cleanflight is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Cleanflight is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+extern "C" {
+#include <platform.h>
+#include "config/parameter_group.h"
+#include "drivers/serial.h"
+#include "io/serial.h"
+#include "fc/rc_controls.h"
+#include "telemetry/telemetry.h"
+#include "telemetry/ibus.h"
+#include "sensors/barometer.h"
+#include "sensors/battery.h"
+#include "scheduler/scheduler.h"
+#include "fc/fc_tasks.h"
+}
+
+#include "unittest_macros.h"
+#include "gtest/gtest.h"
+
+
+extern "C" {
+    uint8_t batteryCellCount = 3;
+    int16_t rcCommand[4] = {0, 0, 0, 0};
+    int16_t telemTemperature1 = 0;
+    baro_t baro = { .baroTemperature = 50 };
+    telemetryConfig_t telemetryConfig_System;
+}
+
+
+#define SERIAL_BUFFER_SIZE 256
+
+typedef struct serialPortStub_s {
+    uint8_t buffer[SERIAL_BUFFER_SIZE];
+    int pos = 0;
+    int end = 0;
+} serialPortStub_t;
+
+
+static uint16_t vbat = 100;
+uint16_t getVbat(void)
+{
+    return vbat;
+}
+
+static serialPortStub_t serialWriteStub;
+static serialPortStub_t serialReadStub;
+
+#define SERIAL_PORT_DUMMY_IDENTIFIER  (serialPortIdentifier_e)0x1234
+serialPort_t serialTestInstance;
+serialPortConfig_t serialTestInstanceConfig = {
+    .identifier = SERIAL_PORT_DUMMY_IDENTIFIER,
+    .functionMask = 0
+};
+
+static serialPortConfig_t *findSerialPortConfig_stub_retval;
+static portSharing_e determinePortSharing_stub_retval;
+static bool openSerial_called = false;
+static bool telemetryDetermineEnabledState_stub_retval;
+
+void rescheduleTask(cfTaskId_e taskId, uint32_t newPeriodMicros)
+{
+    EXPECT_EQ(taskId, TASK_TELEMETRY);
+    EXPECT_EQ(newPeriodMicros, 1000);
+}
+
+
+
+serialPortConfig_t *findSerialPortConfig(serialPortFunction_e function)
+{
+    EXPECT_EQ(function, FUNCTION_TELEMETRY_IBUS);
+    return findSerialPortConfig_stub_retval;
+}
+
+
+portSharing_e determinePortSharing(const serialPortConfig_t *portConfig, serialPortFunction_e function)
+{
+    EXPECT_EQ(portConfig, findSerialPortConfig_stub_retval);
+    EXPECT_EQ(function, FUNCTION_TELEMETRY_IBUS);
+    return PORTSHARING_UNUSED;
+}
+
+
+bool telemetryDetermineEnabledState(portSharing_e portSharing)
+{
+    (void) portSharing;
+    return telemetryDetermineEnabledState_stub_retval;
+}
+
+
+serialPortConfig_t *findSerialPortConfig(uint16_t mask)
+{
+    EXPECT_EQ(mask, FUNCTION_TELEMETRY_IBUS);
+    return findSerialPortConfig_stub_retval ;
+}
+
+
+serialPort_t *openSerialPort(
+    serialPortIdentifier_e identifier,
+    serialPortFunction_e function,
+    serialReceiveCallbackPtr callback,
+    uint32_t baudrate,
+    portMode_t mode,
+    portOptions_t options
+)
+{
+    openSerial_called = true;
+    (void) callback;
+    EXPECT_EQ(identifier, SERIAL_PORT_DUMMY_IDENTIFIER);
+    EXPECT_EQ(options, SERIAL_BIDIR);
+    EXPECT_EQ(function, FUNCTION_TELEMETRY_IBUS);
+    EXPECT_EQ(baudrate, 115200);
+    EXPECT_EQ(mode, MODE_RXTX);
+    return &serialTestInstance;
+}
+
+
+void closeSerialPort(serialPort_t *serialPort)
+{
+    EXPECT_EQ(serialPort, &serialTestInstance);
+}
+
+
+void serialWrite(serialPort_t *instance, uint8_t ch)
+{
+    EXPECT_EQ(instance, &serialTestInstance);
+    EXPECT_LT(serialWriteStub.pos, sizeof(serialWriteStub.buffer));
+    serialWriteStub.buffer[serialWriteStub.pos++] = ch;
+    serialReadStub.buffer[serialReadStub.end++] = ch; //characters echoes back on the shared wire
+    //printf("w: %02d 0x%02x\n", serialWriteStub.pos, ch);
+}
+
+
+uint32_t serialRxBytesWaiting(const serialPort_t *instance)
+{
+    EXPECT_EQ(instance, &serialTestInstance);
+    EXPECT_GE(serialReadStub.end, serialReadStub.pos);
+    int ret = serialReadStub.end - serialReadStub.pos;
+    if (ret < 0) {
+        ret = 0;
+    }
+    //printf("serialRxBytesWaiting: %d\n", ret);
+    return ret;
+}
+
+
+uint8_t serialRead(serialPort_t *instance)
+{
+    EXPECT_EQ(instance, &serialTestInstance);
+    EXPECT_LT(serialReadStub.pos, serialReadStub.end);
+    const uint8_t ch = serialReadStub.buffer[serialReadStub.pos++];
+    return ch;
+}
+
+
+void serialTestResetBuffers()
+{
+    memset(&serialReadStub, 0, sizeof(serialReadStub));
+    memset(&serialWriteStub, 0, sizeof(serialWriteStub));
+}
+
+
+void serialTestResetPort()
+{
+    openSerial_called = false;
+    determinePortSharing_stub_retval = PORTSHARING_UNUSED;
+    telemetryDetermineEnabledState_stub_retval = true;
+
+    serialTestResetBuffers();
+}
+
+
+
+class IbusTelemteryInitUnitTest : public ::testing::Test
+{
+protected:
+    virtual void SetUp()
+    {
+        serialTestResetPort();
+    }
+};
+
+
+TEST_F(IbusTelemteryInitUnitTest, Test_IbusInitNotEnabled)
+{
+    findSerialPortConfig_stub_retval = NULL;
+    telemetryDetermineEnabledState_stub_retval = false;
+
+    //given stuff in serial read
+    serialReadStub.end++;
+
+    //when initializing and polling ibus
+    initIbusTelemetry();
+    checkIbusTelemetryState();
+    handleIbusTelemetry();
+
+    //then nothing is read from serial port
+    EXPECT_NE(serialReadStub.pos, serialReadStub.end);
+    EXPECT_FALSE(openSerial_called);
+}
+
+
+TEST_F(IbusTelemteryInitUnitTest, Test_IbusInitEnabled)
+{
+    findSerialPortConfig_stub_retval = &serialTestInstanceConfig;
+
+    //given stuff in serial read
+    serialReadStub.end++;
+
+    //when initializing and polling ibus
+    initIbusTelemetry();
+    checkIbusTelemetryState();
+    handleIbusTelemetry();
+
+    //then all is read from serial port
+    EXPECT_EQ(serialReadStub.pos, serialReadStub.end);
+    EXPECT_TRUE(openSerial_called);
+}
+
+
+class IbusTelemetryProtocolUnitTestBase : public ::testing::Test
+{
+protected:
+    virtual void SetUp()
+    {
+        telemetryConfigMutable()->report_cell_voltage = false;
+        serialTestResetBuffers();
+        initIbusTelemetry();
+        checkIbusTelemetryState();
+    }
+
+    void checkResponseToCommand(const char *rx, uint8_t rxCnt, const char *expectedTx, uint8_t expectedTxCnt)
+    {
+        serialTestResetBuffers();
+
+        memcpy(serialReadStub.buffer, rx, rxCnt);
+        serialReadStub.end += rxCnt;
+
+        //when polling ibus
+        for (int i = 0; i<10; i++) {
+            handleIbusTelemetry();
+        }
+
+        EXPECT_EQ(expectedTxCnt, serialWriteStub.pos);
+        EXPECT_EQ(0, memcmp(serialWriteStub.buffer, expectedTx, expectedTxCnt));
+    }
+
+    void setupBaseAddressOne(void)
+    {
+        checkResponseToCommand("\x04\x81\x7a\xff", 4, "\x04\x81\x7a\xff", 4);
+        serialTestResetBuffers();
+    }
+
+    void setupBaseAddressThree(void)
+    {
+        checkResponseToCommand("\x04\x83\x78\xff", 4, "\x04\x83\x78\xff", 4);
+        serialTestResetBuffers();
+    }
+};
+
+
+
+class IbusTelemteryProtocolUnitTest : public ::IbusTelemetryProtocolUnitTestBase
+{
+protected:
+    virtual void SetUp()
+    {
+        IbusTelemetryProtocolUnitTestBase::SetUp();
+        setupBaseAddressOne();
+    }
+};
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusNoRespondToDiscoveryCrcErr)
+{
+    //Given ibus command: Hello sensor at address 1, are you there (with bad crc)?
+    //then we do not respond
+    checkResponseToCommand("\x04\x81\x00\x00", 4, NULL, 0);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToDiscovery)
+{
+    //Given ibus command: Hello sensor at address 1, are you there?
+    //then we respond with: Yes, i'm here, hello!
+    checkResponseToCommand("\x04\x81\x7a\xff", 4, "\x04\x81\x7A\xFF", 4);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToSensorTypeQueryVbatt)
+{
+    //Given ibus command: Sensor at address 1, what type are you?
+    //then we respond with: I'm a voltage sensor
+    checkResponseToCommand("\x04\x91\x6A\xFF", 4, "\x06\x91\x03\x02\x63\xFF", 6);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToSensorTypeQueryTemperature)
+{
+    //Given ibus command: Sensor at address 1, what type are you?
+    //then we respond with: I'm a thermometer
+    checkResponseToCommand("\x04\x92\x69\xFF", 4, "\x06\x92\x01\x02\x64\xFF", 6);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToSensorTypeQueryRpm)
+{
+    //Given ibus command: Sensor at address 3, what type are you?
+    //then we respond with: I'm a rpm sensor
+    checkResponseToCommand("\x04\x93\x68\xFF", 4, "\x06\x93\x02\x02\x62\xFF", 6);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToGetMeasurementVbattZero)
+{
+    //Given ibus command: Sensor at address 1, please send your measurement
+    //then we respond with: I'm reading 0 volts
+    vbat = 0;
+    checkResponseToCommand("\x04\xA1\x5a\xff", 4, "\x06\xA1\x00\x00\x58\xFF", 6);
+}
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToGetMeasurementVbattCellVoltage)
+{
+    telemetryConfigMutable()->report_cell_voltage = true;
+
+    //Given ibus command: Sensor at address 1, please send your measurement
+    //then we respond with: I'm reading 0.1 volts
+    batteryCellCount = 3;
+    vbat = 30;
+    checkResponseToCommand("\x04\xA1\x5a\xff", 4, "\x06\xA1\x64\x00\xf4\xFe", 6);
+
+    //Given ibus command: Sensor at address 1, please send your measurement
+    //then we respond with: I'm reading 0.1 volts
+    batteryCellCount = 1;
+    vbat = 10;
+    checkResponseToCommand("\x04\xA1\x5a\xff", 4, "\x06\xA1\x64\x00\xf4\xFe", 6);
+}
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToGetMeasurementVbattPackVoltage)
+{
+    telemetryConfigMutable()->report_cell_voltage = false;
+
+    //Given ibus command: Sensor at address 1, please send your measurement
+    //then we respond with: I'm reading 0.1 volts
+    batteryCellCount = 3;
+    vbat = 10;
+    checkResponseToCommand("\x04\xA1\x5a\xff", 4, "\x06\xA1\x64\x00\xf4\xFe", 6);
+
+    //Given ibus command: Sensor at address 1, please send your measurement
+    //then we respond with: I'm reading 0.1 volts
+    batteryCellCount = 1;
+    vbat = 10;
+    checkResponseToCommand("\x04\xA1\x5a\xff", 4, "\x06\xA1\x64\x00\xf4\xFe", 6);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToGetMeasurementTemperature)
+{
+#ifdef BARO
+    //Given ibus command: Sensor at address 2, please send your measurement
+    //then we respond
+    baro.baroTemperature = 50;
+    checkResponseToCommand("\x04\xA2\x59\xff", 4, "\x06\xA2\x95\x01\xc1\xFE", 6);
+
+    //Given ibus command: Sensor at address 2, please send your measurement
+    //then we respond
+    baro.baroTemperature = 59;  //test integer rounding
+    checkResponseToCommand("\x04\xA2\x59\xff", 4, "\x06\xA2\x96\x01\xc0\xFE", 6);
+
+    //Given ibus command: Sensor at address 2, please send your measurement
+    //then we respond
+    baro.baroTemperature = 150;
+    checkResponseToCommand("\x04\xA2\x59\xff", 4, "\x06\xA2\x9f\x01\xb7\xFE", 6);
+#else
+    #error not tested, may be obsolete
+    // //Given ibus command: Sensor at address 2, please send your measurement
+    // //then we respond with: I'm reading 0 degrees + constant offset 0x190
+    // telemTemperature1 = 0;
+    // checkResponseToCommand("\x04\xA2\x59\xff", 4, "\x06\xA2\x90\x01\xC6\xFE", 6);
+
+    // //Given ibus command: Sensor at address 2, please send your measurement
+    // //then we respond with: I'm reading 100 degrees + constant offset 0x190
+    // telemTemperature1 = 100;
+    // checkResponseToCommand("\x04\xA2\x59\xff", 4, "\x06\xA2\xF4\x01\x62\xFE", 6);
+#endif
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTest, Test_IbusRespondToGetMeasurementRpm)
+{
+    //Given ibus command: Sensor at address 3, please send your measurement
+    //then we respond with: I'm reading 0 rpm
+    rcCommand[THROTTLE] = 0;
+    checkResponseToCommand("\x04\xA3\x58\xff", 4, "\x06\xA3\x00\x00\x56\xFF", 6);
+
+    //Given ibus command: Sensor at address 3, please send your measurement
+    //then we respond with: I'm reading 100 rpm
+    rcCommand[THROTTLE] = 100;
+    checkResponseToCommand("\x04\xA3\x58\xff", 4, "\x06\xA3\x64\x00\xf2\xFe", 6);
+}
+
+
+
+class IbusTelemteryProtocolUnitTestDaisyChained : public ::IbusTelemetryProtocolUnitTestBase
+{
+protected:
+    virtual void SetUp()
+    {
+        IbusTelemetryProtocolUnitTestBase::SetUp();
+        setupBaseAddressThree();
+    }
+};
+
+
+TEST_F(IbusTelemteryProtocolUnitTestDaisyChained, Test_IbusRespondToDiscoveryBaseAddressThree)
+{
+    //Given ibus commands: Hello sensor at address 3, 4, 5 are you there?
+    //then we respond with: Yes, we're here, hello!
+    checkResponseToCommand("\x04\x83\x78\xff", 4, "\x04\x83\x78\xff", 4);
+    checkResponseToCommand("\x04\x84\x77\xff", 4, "\x04\x84\x77\xff", 4);
+    checkResponseToCommand("\x04\x85\x76\xff", 4, "\x04\x85\x76\xff", 4);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTestDaisyChained, Test_IbusRespondToSensorTypeQueryWrongAddress)
+{
+    //Given ibus commands: Sensor at address 1, 2, 6, what type are you?
+    //then we do not respond
+    checkResponseToCommand("\x04\x91\x6A\xFF", 4, "", 0);
+    checkResponseToCommand("\x04\x92\x69\xFF", 4, "", 0);
+
+    checkResponseToCommand("\x04\x96\x65\xFF", 4, "", 0);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTestDaisyChained, Test_IbusRespondToSensorTypeQueryVbattBaseThree)
+{
+    //Given ibus commands: Sensor at address 3, 4, 5, what type are you?
+    //then we respond with: I'm a voltage sensor
+    checkResponseToCommand("\x04\x93\x68\xFF", 4, "\x06\x93\x03\x02\x61\xFF", 6);
+    //then we respond with: I'm a thermometer
+    checkResponseToCommand("\x04\x94\x67\xFF", 4, "\x06\x94\x01\x02\x62\xFF", 6);
+    //then we respond with: I'm a rpm sensor
+    checkResponseToCommand("\x04\x95\x66\xFF", 4, "\x06\x95\x02\x02\x60\xFF", 6);
+}
+
+
+TEST_F(IbusTelemteryProtocolUnitTestDaisyChained, Test_IbusRespondToGetMeasurementsBaseThree)
+{
+    //Given ibus command: Sensor at address 3, please send your measurement
+    //then we respond with: I'm reading 0.1 volts
+    batteryCellCount = 1;
+    vbat = 10;
+    checkResponseToCommand("\x04\xA3\x58\xff", 4, "\x06\xA3\x64\x00\xf2\xFe", 6);
+
+#ifdef BARO
+    //Given ibus command: Sensor at address 4, please send your measurement
+    //then we respond
+    baro.baroTemperature = 150;
+    checkResponseToCommand("\x04\xA4\x57\xff", 4, "\x06\xA4\x9f\x01\xb5\xFE", 6);
+#else
+    //Given ibus command: Sensor at address 4, please send your measurement
+    //then we respond with: I'm reading 100 degrees + constant offset 0x190
+    telemTemperature1 = 100;
+    checkResponseToCommand("\x04\xA4\x57\xff", 4, "\x06\xA4\xF4\x01\x60\xFE", 6);
+#endif
+
+    //Given ibus command: Sensor at address 5, please send your measurement
+    //then we respond with: I'm reading 100 rpm
+    rcCommand[THROTTLE] = 100;
+    checkResponseToCommand("\x04\xA5\x56\xff", 4, "\x06\xA5\x64\x00\xf0\xFe", 6);
+}