1 files changed, 21 insertions, 3 deletions
diff --git a/rotaryencoder.cpp b/rotaryencoder.cpp
index 41d56e8..62ca33d 100644
--- a/rotaryencoder.cpp
+++ b/rotaryencoder.cpp
@@ -26,7 +26,7 @@ const std::vector<int> encoderTable = {
     0, 1, -1, 0, -1, 0, 0, 1, 1, 0, 0, -1, 0, -1, 1, 0
 };
 
-volatile int64_t positionSteps;
+volatile int32_t positionSteps;
 volatile uint8_t state;
 
 void pin_isr(void) {
@@ -55,8 +55,14 @@ void pin_isr(void) {
     }
 }
 
-rotaryencoder::rotaryencoder()
+RotaryEncoder::RotaryEncoder()
 {
+    if (!m_self) {
+        m_self = this;
+    } else {
+        qWarning() << "normally there should be only one instance of RotaryEncoder";
+    }
+
     QElapsedTimer t;
     t.start();
 
@@ -101,7 +107,19 @@ rotaryencoder::rotaryencoder()
     // }
 }
 
-int64_t rotaryencoder::position() const
+RotaryEncoder::~RotaryEncoder()
+{
+    if (m_self == this) {
+        m_self = nullptr;
+    }
+}
+
+RotaryEncoder *RotaryEncoder::instance()
+{
+    return m_self;
+}
+
+int32_t RotaryEncoder::position() const
 {
     return ::positionSteps;
 }