Revert "Use assembly impl"

This reverts commit 698c8e7.

src/Joystick.cpp

@@ -2,14 +2,15 @@
 
 #include <avr/io.h>
 
-extern "C" void joystickInitImpl();
-extern "C" int analogReadImpl();
-
 #define IDLE_VALUE 512
 
 Joystick::Joystick(unsigned int sensitivity) : invertedSensitivity(IDLE_VALUE - sensitivity)
 {
-    joystickInitImpl();
+    DDRB &= ~(1 << DDB0);
+
+    ADCSRA |= (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);
+    ADMUX |= (1 << REFS0);
+    ADCSRA |= (1 << ADEN);
 }
 
 unsigned int Joystick::getX() const
@@ -64,5 +65,10 @@ bool Joystick::isPressed() const
 
 unsigned int Joystick::analogRead() const
 {
-    return analogReadImpl();
+    ADCSRA |= (1 << ADSC);
+    while (ADCSRA & (1 << ADSC))
+    {
+        // wait for the reading
+    }
+    return ADC;
 }