Small changes to work with more Blue Pills

src/main.rs

@@ -118,6 +118,10 @@ fn main() -> ! {
     let scl = gpiob.pb10.into_alternate_open_drain(&mut gpiob.crh);
     let sda = gpiob.pb11.into_alternate_open_drain(&mut gpiob.crh);
 
+    // Very brief delay before starting up i2c; otherwise the startup process
+    // could hang.
+    delay.delay_us(10_u8);
+
     // Configure the I2C peripheral itself
     let i2c = BlockingI2c::i2c2(
         dev_periph.I2C2,
@@ -166,9 +170,6 @@ fn main() -> ! {
     // Turn the LED on via the OutputPin trait
     led.on().unwrap();
 
-    // Very brief delay before the loop, just to show how
-    delay.delay_us(10_u8);
-
     let mut button_last = false;
     // Microcontroller programs never exit main, so we must loop!
     loop {