diff --git a/libraries/hardware.cpp b/libraries/hardware.cpp
index 9695416..47f46a3 100644
--- a/libraries/hardware.cpp
+++ b/libraries/hardware.cpp
@@ -66,6 +66,10 @@ namespace picosystem {
     return !(_io & (1U << b)) && (_lio & (1U << b));
   }
 
+  bool released(uint32_t b) {
+    return (_io & (1U << b)) && !(_lio & (1U << b));
+  }
+
   bool button(uint32_t b) {
     return !(_io & (1U << b));
   }
diff --git a/libraries/picosystem.hpp b/libraries/picosystem.hpp
index c0cbf05..e648d93 100644
--- a/libraries/picosystem.hpp
+++ b/libraries/picosystem.hpp
@@ -220,6 +220,7 @@ namespace picosystem {
 
   // hardware
   bool        pressed(uint32_t b);
+  bool        released(uint32_t b);
   bool        button(uint32_t b);
   uint32_t    battery();
   void        led(uint8_t r, uint8_t g, uint8_t b);