diff --git a/chip/zgpio.cpp b/chip/zgpio.cpp
index 4167f11..02d1d45 100644
--- a/chip/zgpio.cpp
+++ b/chip/zgpio.cpp
@@ -133,7 +133,7 @@ void regIRQGPIO(ZGPIO *gpio) {
 
 bool ZGPIO::isMirror() { return m_mirror; }
 void ZGPIO::initAsInput(Pin_t pin, GPIOMode_t mode, GPIOIrqType_t irqtype, bool mirror) {
-  ZEARLY_ASSERT(pin != PinNull);
+  if (pin == PinNull) return;
 
   m_mirror   = mirror;
   m_mode     = mode;
@@ -188,7 +188,8 @@ void ZGPIO::initAsInput(Pin_t pin, GPIOMode_t mode, GPIOIrqType_t irqtype, bool
   return;
 }
 void ZGPIO::initAsOutput(Pin_t pin, GPIOMode_t mode, bool mirror, bool initLevel) {
-  ZEARLY_ASSERT(pin != PinNull);
+  if (pin == PinNull) return;
+
   m_mirror   = mirror;
   m_mode     = mode;
   m_irqtype  = kIRQ_noIrq;
@@ -301,6 +302,7 @@ uint32_t ZGPIO::getStateUint32() {
 }
 
 bool ZGPIO::getState() {
+  if (m_pin == PinNull) return false;
   bool ret = false;
   if (HAL_GPIO_ReadPin(m_gpio, m_pinoff) == GPIO_PIN_SET) {
     ret = true;
@@ -311,6 +313,8 @@ bool ZGPIO::getState() {
   return ret;
 }
 bool ZGPIO::setState(bool state) {
+  if (m_pin == PinNull) return true;
+  
   if (m_mirror) state = !state;
 
   if (m_log_when_setstate) ZEARLY_LOGI(TAG, "%s%s set %d", chip_gpio_group_get_name(m_gpio), chip_pinoff_get_name(m_pinoff), state);
diff --git a/chip/zgpio.hpp b/chip/zgpio.hpp
index 674cc0c..bf44d3b 100644
--- a/chip/zgpio.hpp
+++ b/chip/zgpio.hpp
@@ -49,7 +49,7 @@ class ZGPIO {
   } OutputGpioCfg_t;
 
  private:
-  Pin_t         m_pin;
+  Pin_t         m_pin = PinNull;
   GPIO_TypeDef *m_gpio;
   uint16_t      m_pinoff;
   GPIOType_t    m_gpiotype;
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 b5b416d..4bab63a 100644
--- a/components/step_motor_ctrl_module/step_motor_ctrl_module.cpp
+++ b/components/step_motor_ctrl_module/step_motor_ctrl_module.cpp
@@ -605,7 +605,7 @@ int32_t StepMotorCtrlModule::factory_reset() {
 void StepMotorCtrlModule::active_cfg() {
   m_stepM1->setIHOLD_IRUN(m_param.ihold, m_param.irun, m_param.iholddelay);
   m_stepM1->setScale(m_param.distance_scale);
-  m_stepM1->setScale(m_param.distance_scale_denominator);
+  m_stepM1->setScaleDenominator(m_param.distance_scale_denominator);
   m_stepM1->setMotorShaft(m_param.x_shaft);
 }
 
@@ -700,6 +700,8 @@ int32_t StepMotorCtrlModule::module_get_reg(int32_t param_id, int32_t* val) {
     GET_REG(kreg_motor_default_velocity, m_param.maxspeed);
     GET_REG(kreg_motor_default_acc, m_param.acc);
     GET_REG(kreg_motor_default_dec, m_param.dec);
+    GET_REG(kreg_module_input_state, _read_io());
+
     // GET_REG(kreg_motor_default_break_dec, m_param.dec);
     GET_REG(kreg_motor_run_to_zero_max_d, m_param.run_to_zero_max_d);
     GET_REG(kreg_motor_look_zero_edge_max_d, m_param.look_zero_edge_max_d);
@@ -741,6 +743,11 @@ int32_t StepMotorCtrlModule::module_readio(int32_t* io) {
   }
   return 0;
 }
+int32_t StepMotorCtrlModule::_read_io() {
+  int32_t iostate = 0;
+  module_readio(&iostate);
+  return iostate;
+}
 
 int32_t StepMotorCtrlModule::module_read_adc(int32_t adcindex, int32_t* adc) {
   *adc = 0;
diff --git a/components/step_motor_ctrl_module/step_motor_ctrl_module.hpp b/components/step_motor_ctrl_module/step_motor_ctrl_module.hpp
index 3655e82..1445242 100644
--- a/components/step_motor_ctrl_module/step_motor_ctrl_module.hpp
+++ b/components/step_motor_ctrl_module/step_motor_ctrl_module.hpp
@@ -188,5 +188,7 @@ class StepMotorCtrlModule : public I_StepMotorCtrlModule, public ZIModule, publi
 
   void call_exec_status_cb(int32_t status, action_cb_status_t status_cb);
   void set_last_exec_status(int32_t ecode, int32_t val0 = 0, int32_t val1 = 0, int32_t val2 = 0, int32_t val3 = 0, int32_t val4 = 0, int32_t val5 = 0);
+  private:
+  int32_t _read_io();
 };
 }  // namespace iflytop
\ No newline at end of file