► Warning fixes

- Changed all float constants to use f suffix to prevent double conversions
- Removed compile warnings due to HAL_GPIO_* related calls
- Added comms.h with prototypes for functions which were used in main()
- Casts and externs to fix compile warnings in various files.
- Made a bunch of file-local variables static.
- Fixed buzzerFreq/buzzerPattern extern declarations with correct type (uint8_t)
- Since this is C, void func() { } needs to be void func(void) { }, so fixed that in all instances.
These updates follows from @trollcop

Src/setup.c

@@ -53,7 +53,7 @@ volatile adc_buf_t adc_buffer;
 #ifdef CONTROL_SERIAL_USART2
 
 
-void UART_Control_Init() {
+void UART_Control_Init(void) {
   GPIO_InitTypeDef GPIO_InitStruct;
   __HAL_RCC_USART2_CLK_ENABLE();
   /* DMA1_Channel6_IRQn interrupt configuration */
@@ -123,7 +123,7 @@ HAL_DMA_Init(&hdma_usart2_tx);
 #endif
 
 #ifdef DEBUG_SERIAL_USART3
-void UART_Init() {
+void UART_Init(void) {
   __HAL_RCC_USART3_CLK_ENABLE();
   __HAL_RCC_DMA1_CLK_ENABLE();
 
@@ -156,7 +156,7 @@ void UART_Init() {
 #endif
 
 #ifdef DEBUG_SERIAL_USART2
-void UART_Init() {
+void UART_Init(void) {
   __HAL_RCC_USART2_CLK_ENABLE();
   __HAL_RCC_DMA1_CLK_ENABLE();
 
@@ -189,7 +189,7 @@ void UART_Init() {
 #endif
 
 /*
-void UART_Init() {
+void UART_Init(void) {
   __HAL_RCC_USART2_CLK_ENABLE();
   __HAL_RCC_DMA1_CLK_ENABLE();
 
@@ -224,7 +224,7 @@ void UART_Init() {
 DMA_HandleTypeDef hdma_i2c2_rx;
 DMA_HandleTypeDef hdma_i2c2_tx;
 
-void I2C_Init()
+void I2C_Init(void)
 {
 
   __HAL_RCC_I2C2_CLK_ENABLE();