diff --git a/ch32v-insert-coin/src/app.rs b/ch32v-insert-coin/src/app.rs
index 2eb5de9..482c354 100644
--- a/ch32v-insert-coin/src/app.rs
+++ b/ch32v-insert-coin/src/app.rs
@@ -310,6 +310,7 @@ pub struct Interfaces {
     pub pwm_core: SimplePwmCore<'static, ch32_hal::peripherals::TIM1>,
     pub adc_core: crate::AdcCore,
     pub amp: crate::Amplifier,
+    pub usb: crate::Usb,
 }
 
 pub struct App {
@@ -400,12 +401,14 @@ impl App {
         }
         if self.timers.batt_adc_timer.need_service() {
             self.timers.batt_adc_timer.service();
-            let bv = self.interfaces.adc_core.get_battery_voltage();
-            let avg = self.interfaces.adc_core.get_average();
-            // #[cfg(feature = "enable_print")]
-            // println!("batt adc service: {bv}, {avg}");
-            if avg < 421 {
-                self.set_state(State::DeepSleep);
+            if !self.interfaces.usb.powered() {
+                let bv = self.interfaces.adc_core.get_battery_voltage();
+                let avg = self.interfaces.adc_core.get_average();
+                // #[cfg(feature = "enable_print")]
+                // println!("batt adc service: {bv}, {avg}");
+                if avg < 421 {
+                    self.set_state(State::DeepSleep);
+                }
             }
         }
         if self.timers.usb_adc_timer.need_service() {
diff --git a/ch32v-insert-coin/src/main.rs b/ch32v-insert-coin/src/main.rs
index 6a29a7a..0bb8271 100644
--- a/ch32v-insert-coin/src/main.rs
+++ b/ch32v-insert-coin/src/main.rs
@@ -44,6 +44,19 @@ use crate::app::sequencer::{DynamicSequence, SequenceEntry};
 
 static LED0_SEQ: [u8; 8] = [0u8, 25u8, 50u8, 75u8, 100u8, 75u8, 50u8, 25u8];
 
+pub struct Usb {
+    usb_pin: Input<'static>,
+}
+
+impl Usb {
+    pub fn new(usb_pin: Input<'static>) -> Self {
+        Self { usb_pin }
+    }
+    pub fn powered(&self) -> bool {
+        self.usb_pin.is_high()
+    }
+}
+
 pub struct Amplifier {
     amp_en: Output<'static>,
 }
@@ -276,6 +289,8 @@ fn app_main(mut p: hal::Peripherals) -> ! {
     // adc2
     // let mut usb_detect_dc = hal::adc::Adc::new(p.ADC1, Default::default());
     let mut usb_detect_pin = p.PD5;
+    let usb_detect_input = Input::new(usb_detect_pin, Pull::Down);
+    let usb = Usb::new(usb_detect_input);
 
     // println!("ADC_PIN CHANNEL: {}", adc_pin.channel().channel());
 
@@ -360,6 +375,7 @@ fn app_main(mut p: hal::Peripherals) -> ! {
         pwm_core,
         adc_core,
         amp,
+        usb,
     };
 
     let mut app = App::new(app_config, app_services, app_sequences, app_interfaces);