diff --git a/examples/ext_dev/cotrollers/motor_tmc2209/screw_slide_2axis_scan.py b/examples/ext_dev/cotrollers/motor_tmc2209/screw_slide_2axis_scan.py
new file mode 100644
index 00000000..2ecd6a0e
--- /dev/null
+++ b/examples/ext_dev/cotrollers/motor_tmc2209/screw_slide_2axis_scan.py
@@ -0,0 +1,122 @@
+from maix import ext_dev, display, camera, pinmap, time, err, app
+import threading
+
+### MODE
+MODE_SHOW_PICTURE = 0
+MODE_SHOW_VIDEO = 1
+
+# If you have high frame requirement,
+# please use cdk, refer to MaixCDK/example/maix_tmc2209_2axis_scan.
+
+### Change mode according to your needs
+MODE = MODE_SHOW_PICTURE
+
+if __name__ == "__main__":
+
+    if MODE == MODE_SHOW_PICTURE:
+        print("Mode: show picture")
+    elif MODE == MODE_SHOW_VIDEO:
+        print("Mode: show video")
+    else:
+        print("Error Mode: ", MODE)
+        exit(-1)
+
+    cam = camera.Camera(512, 320)
+    disp = display.Display()
+
+    port = "/dev/ttyS1"
+    uart_baudrate = 115200
+
+    uart_addr_x = 0x00
+    step_angle_x = 18
+    micro_step_x = 256
+    screw_pitch_x = 3.0
+    speed_x = 1.0
+    dir_x = True
+    start_x = 0
+    stop_x = 20
+    step_x = 3
+
+    uart_addr_y = 0x03
+    step_angle_y = 18
+    micro_step_y = 256
+    screw_pitch_y = 3.0
+    speed_y = 1.0
+    dir_y = False
+    start_y = 0
+    stop_y = 15
+    step_y = 3
+
+    if pinmap.set_pin_function("A19", "UART1_TX") != err.Err.ERR_NONE:
+        print("pinmap error!")
+        exit(-1)
+    if pinmap.set_pin_function("A18", "UART1_RX") != err.Err.ERR_NONE:
+        print("pinmap error!")
+        exit(-1)
+
+    slide_x = ext_dev.tmc2209.ScrewSlide(
+        port,
+        uart_addr_x,
+        uart_baudrate,
+        step_angle_x,
+        micro_step_x,
+        screw_pitch_x,
+        speed_x
+    )
+
+    slide_y = ext_dev.tmc2209.ScrewSlide(
+        port,
+        uart_addr_y,
+        uart_baudrate,
+        step_angle_y,
+        micro_step_y,
+        screw_pitch_y,
+        speed_y
+    )
+
+    need_exit = False
+
+    def one_step_callback():
+        global need_exit, cam, disp
+        img = cam.read()
+        disp.show(img)
+        return need_exit
+
+    def thread_func():
+        while not app.need_exit():
+            if one_step_callback():
+                break
+
+
+    if MODE == MODE_SHOW_VIDEO:
+        th = threading.Thread(target=thread_func)
+        th.daemon = True
+        th.start()
+
+    current_x = start_x if dir_x else stop_x
+    current_y = start_y if dir_y else stop_y
+
+    dir_x_ = dir_x
+
+    for i in range(0, (stop_y-start_y)//step_y+1):
+        target_move_y = step_y if i != 0 else 0
+        target_move_y = target_move_y if dir_y else -target_move_y
+        slide_y.move(target_move_y)
+        current_y = current_y + step_y if dir_y else current_y - step_y
+
+        for j in range(0, (stop_x-start_x)//2):
+            target_move_x = step_x if dir_x_ else -step_x
+            slide_x.move(target_move_x)
+            current_x += target_move_x
+            if MODE == MODE_SHOW_PICTURE:
+                one_step_callback()
+            if app.need_exit():
+                break
+
+        dir_x_ = False if dir_x_ else True
+        if app.need_exit():
+            break
+
+    need_exit = True
+
+    time.sleep(3)
\ No newline at end of file
diff --git a/examples/protocol/comm_modbus_master_rtu.py b/examples/protocol/comm_modbus_master_rtu.py
new file mode 100644
index 00000000..306fbc3e
--- /dev/null
+++ b/examples/protocol/comm_modbus_master_rtu.py
@@ -0,0 +1,38 @@
+from maix import pinmap, app, err, time, thread
+from maix.comm import modbus
+
+
+REGISTERS_START_ADDRESS = 0x00
+REGISTERS_NUMBER = 10
+
+RTU_SLAVE_ID = 1
+RTU_BAUDRATE = 115200
+
+def master_thread(*args):
+    if pinmap.set_pin_function("A19", "UART1_TX") != err.Err.ERR_NONE:
+        print("init uart1 failed!")
+        exit(-1)
+    if pinmap.set_pin_function("A18", "UART1_RX") != err.Err.ERR_NONE:
+        print("init uart1 failed!")
+        exit(-1)
+
+    # modbus.set_master_debug(True)
+
+    master = modbus.MasterRTU(
+        "/dev/ttyS1",
+        RTU_BAUDRATE
+    )
+
+    while not app.need_exit():
+        hr = master.read_holding_registers(
+            RTU_SLAVE_ID,
+            REGISTERS_START_ADDRESS,
+            REGISTERS_NUMBER,
+            2000
+        )
+        if len(hr) == 0:
+            continue
+        print("Master read hr: ", hr)
+        time.sleep(1)
+
+master_thread(None)
\ No newline at end of file