diff --git a/ch32v-insert-coin/src/main.rs b/ch32v-insert-coin/src/main.rs
index 3f9e9ef..3ff6126 100644
--- a/ch32v-insert-coin/src/main.rs
+++ b/ch32v-insert-coin/src/main.rs
@@ -45,10 +45,17 @@ use adpcm_pwm_dac::{interface::DacInterface, dac::Dac};
 impl<T> DacInterface for SimplePwmDacPin<'_, T> 
 where T: GeneralInstance16bit {
     fn write_amplitude(&mut self, amplitude: u8) {
+        if !self.pin.is_enabled(self.ch) {
+            self.pin.enable(self.ch);
+        }
         let max_duty = self.pin.get_max_duty();
         let dc = amplitude as u32 * max_duty / 100;
         self.pin.set_duty(self.ch, dc);
     }
+
+    fn disable(&mut self) {
+        self.pin.disable(self.ch);
+    }
 }
 
 fn blink(pin: AnyPin, interval_ms: u64) {