The GPIOs of STM32G4 have 16 alternate functions, not 8.

Author: mgottschlag

src/gpio.rs

@@ -72,6 +72,14 @@ pub const AF4: u8 = 4;
 pub const AF5: u8 = 5;
 pub const AF6: u8 = 6;
 pub const AF7: u8 = 7;
+pub const AF8: u8 = 8;
+pub const AF9: u8 = 9;
+pub const AF10: u8 = 10;
+pub const AF11: u8 = 11;
+pub const AF12: u8 = 12;
+pub const AF13: u8 = 13;
+pub const AF14: u8 = 14;
+pub const AF15: u8 = 15;
 
 /// External Interrupt Pin
 pub trait ExtiPin {