From d37d5726ce73cdbfe1df4f537998b4b7e0d0df01 Mon Sep 17 00:00:00 2001
From: Michael Mogenson <michael.mogenson@gmail.com>
Date: Wed, 27 Mar 2019 11:37:44 -0400
Subject: [PATCH 1/2] write_fmt() method needed for write!() macro

Include `use core::fmt::Write;` in serial example.
---
 src/hello-world/02.00.UART.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/hello-world/02.00.UART.md b/src/hello-world/02.00.UART.md
index b661a02..4b7af7d 100644
--- a/src/hello-world/02.00.UART.md
+++ b/src/hello-world/02.00.UART.md
@@ -24,6 +24,7 @@ To read and write to the serial bus from your computer, you will need to configu
 ## Code
 
 ``` rust
+use core::fmt::Write;
 use microbit::hal::prelude::*;
 use microbit::hal::serial;
 use microbit::hal::serial::BAUD115200;

From 7641877efec4096d6e2224cb86aa92bd47ccad01 Mon Sep 17 00:00:00 2001
From: Michael Mogenson <michael.mogenson@gmail.com>
Date: Wed, 27 Mar 2019 11:39:35 -0400
Subject: [PATCH 2/2] Remove unused mut

`gpio` does not need to be mutable. Remove `mut` to silence build
warning.
---
 src/hello-world/02.00.UART.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/hello-world/02.00.UART.md b/src/hello-world/02.00.UART.md
index 4b7af7d..b3452cb 100644
--- a/src/hello-world/02.00.UART.md
+++ b/src/hello-world/02.00.UART.md
@@ -30,7 +30,7 @@ use microbit::hal::serial;
 use microbit::hal::serial::BAUD115200;
 // -- snip --
 if let Some(p) = microbit::Peripherals::take() {
-    let mut gpio = p.GPIO.split();
+    let gpio = p.GPIO.split();
     // Configure RX and TX pins accordingly
     let tx = gpio.pin24.into_push_pull_output().downgrade();
     let rx = gpio.pin25.into_floating_input().downgrade();