diff --git a/components/step_motor_ctrl_module/step_motor_ctrl_module.cpp b/components/step_motor_ctrl_module/step_motor_ctrl_module.cpp
index 22a512f..24d4620 100644
--- a/components/step_motor_ctrl_module/step_motor_ctrl_module.cpp
+++ b/components/step_motor_ctrl_module/step_motor_ctrl_module.cpp
@@ -20,6 +20,13 @@ int32_t StepMotorCtrlModule::move_to(int32_t tox, function<void(move_to_cb_statu
   ZLOGI(TAG, "m%d move_to %d", m_id, tox);
   m_thread.stop();
 
+  if (m_cfg_min_x != 0 && tox < m_cfg_min_x) {
+    tox = m_cfg_min_x;
+  }
+  if (m_cfg_max_x != 0 && tox > m_cfg_max_x) {
+    tox = m_cfg_max_x;
+  }
+
   updateStatus(1);
   m_thread.start([this, tox, status_cb]() {
     _motor_move_to(tox, m_cfg_velocity, m_cfg_acc, m_cfg_dec);
@@ -48,14 +55,12 @@ int32_t StepMotorCtrlModule::move_by(int32_t dx, function<void(move_by_cb_status
   getnowpos(xnow);
 
   int32_t toxnow = xnow + dx;
-  move_to(toxnow, [this, status_cb, xnow](move_to_cb_status_t& status) {
+  return move_to(toxnow, [this, status_cb, xnow](move_to_cb_status_t& status) {
     move_by_cb_status_t movebycb_status;
     movebycb_status.exec_status = status.exec_status;
     movebycb_status.dx          = status.tox - xnow;
     if (status_cb) status_cb(movebycb_status);
   });
-
-  return 0;
 }
 int32_t StepMotorCtrlModule::move_to_zero(function<void(move_to_zero_cb_status_t& status)> status_cb) {
   zlock_guard lock(m_lock);
@@ -349,7 +354,7 @@ void StepMotorCtrlModule::_motor_move_by(int32_t dpos, int32_t maxv, int32_t acc
   getnowpos(nowpos);
 
   int32_t topos    = nowpos + dpos;
-  int     motorpos = 0;
+  int32_t motorpos = 0;
   forward_kinematics(topos, motorpos);
   m_stepM1->moveTo(motorpos, maxv);
 }