diff --git a/part8-breakout-ble/Makefile b/part8-breakout-ble/Makefile
index 44bd023..143c51b 100644
--- a/part8-breakout-ble/Makefile
+++ b/part8-breakout-ble/Makefile
@@ -1,7 +1,7 @@
 CFILES = $(wildcard *.c)
 OFILES = $(CFILES:.c=.o)
 LLVMPATH = /opt/homebrew/opt/llvm/bin
-GCCFLAGS = -Wall -O0 -ffreestanding -nostdinc -nostdlib -mcpu=cortex-a72+nosimd
+GCCFLAGS = -Wall -O2 -ffreestanding -nostdinc -nostdlib -mcpu=cortex-a72+nosimd
 
 all: clean kernel8.img
 
diff --git a/part8-breakout-ble/Makefile.gcc.windows b/part8-breakout-ble/Makefile.gcc.windows
index ee18c88..349a29b 100644
--- a/part8-breakout-ble/Makefile.gcc.windows
+++ b/part8-breakout-ble/Makefile.gcc.windows
@@ -1,6 +1,6 @@
 CFILES = $(wildcard *.c)
 OFILES = $(CFILES:.c=.o)
-GCCFLAGS = -Wall -O0 -ffreestanding -nostdinc -nostdlib -nostartfiles
+GCCFLAGS = -Wall -O2 -ffreestanding -nostdinc -nostdlib -nostartfiles
 GCCPATH = ..\..\gcc-arm-10.2-2020.11-mingw-w64-i686-aarch64-none-elf\bin
 
 all: clean kernel8.img
diff --git a/part8-breakout-ble/bt.c b/part8-breakout-ble/bt.c
index 7d148fe..5fbf048 100644
--- a/part8-breakout-ble/bt.c
+++ b/part8-breakout-ble/bt.c
@@ -1,7 +1,7 @@
 #include "io.h"
 #include "fb.h"
 
-unsigned char *params = (unsigned char *)SAFE_ADDRESS;
+volatile unsigned char *params = (unsigned char *)SAFE_ADDRESS;
 
 // UART0
 
@@ -93,7 +93,7 @@ enum {
 
 unsigned char empty[] = {};
 
-int hciCommandBytes(unsigned char *opcodebytes, unsigned char *data, unsigned char length)
+int hciCommandBytes(volatile unsigned char *opcodebytes, volatile unsigned char *data, unsigned char length)
 {
     unsigned char c=0;
 
@@ -130,7 +130,7 @@ int hciCommandBytes(unsigned char *opcodebytes, unsigned char *data, unsigned ch
     return 0;
 }
 
-int hciCommand(unsigned short ogf, unsigned short ocf, unsigned char *data, unsigned char length)
+int hciCommand(unsigned short ogf, unsigned short ocf, volatile unsigned char *data, unsigned char length)
 {
     unsigned short opcode = ogf << 10 | ocf;
     unsigned char opcodebytes[2] = { lo(opcode), hi(opcode) };
@@ -233,6 +233,7 @@ void sendACLsubscribe(unsigned int handle)
     params[4] = 0x00;
 
     unsigned int c=0;
+
     while (c++<data_length) bt_writeByte(params[c-1]);
 }
 
diff --git a/part8-breakout-ble/kernel.c b/part8-breakout-ble/kernel.c
index 8a0ee7a..f143fe6 100644
--- a/part8-breakout-ble/kernel.c
+++ b/part8-breakout-ble/kernel.c
@@ -368,7 +368,7 @@ void breakout()
           }
        }
 
-       //wait_msec(0x186A);
+       wait_msec(0x186A);
        moveObjectAbs(ball, ball->x + velocity_x, ball->y + velocity_y);
 
        // Check we're in the game arena still