diff --git a/src/main/common/printf.h b/src/main/common/printf.h
index dff4efdd2..ac5493590 100644
--- a/src/main/common/printf.h
+++ b/src/main/common/printf.h
@@ -120,5 +120,7 @@ int tfp_format(void *putp, void (*putf) (void *, char), const char *fmt, va_list
 #define sprintf tfp_sprintf
 
 void setPrintfSerialPort(serialPort_t *serialPort);
+void printfSupportInit(void);
+
 
 #endif
diff --git a/src/main/drivers/accgyro_lsm303dlhc.c b/src/main/drivers/accgyro_lsm303dlhc.c
index c3ea4968e..80a270b9f 100644
--- a/src/main/drivers/accgyro_lsm303dlhc.c
+++ b/src/main/drivers/accgyro_lsm303dlhc.c
@@ -19,6 +19,9 @@
 #include <stdint.h>
 
 #include "platform.h"
+
+#ifdef USE_ACC_LSM303DLHC
+
 #include "debug.h"
 
 #include "common/maths.h"
@@ -167,4 +170,4 @@ bool lsm303dlhcAccDetect(acc_t *acc)
     acc->read = lsm303dlhcAccRead;
     return true;
 }
-
+#endif
diff --git a/src/main/drivers/bus_i2c_stm32f30x.c b/src/main/drivers/bus_i2c_stm32f30x.c
index 524df1bc8..88b267f11 100644
--- a/src/main/drivers/bus_i2c_stm32f30x.c
+++ b/src/main/drivers/bus_i2c_stm32f30x.c
@@ -132,10 +132,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t data)
         }
     }
 
-        /* Configure slave address, nbytes, reload, end mode and start or stop generation */
+    /* Configure slave address, nbytes, reload, end mode and start or stop generation */
     I2C_TransferHandling(I2Cx, addr_, 1, I2C_Reload_Mode, I2C_Generate_Start_Write);
 
-        /* Wait until TXIS flag is set */
+    /* Wait until TXIS flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_TXIS) == RESET) {
         if ((i2cTimeout--) == 0) {
@@ -143,10 +143,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t data)
         }
     }
 
-        /* Send Register address */
+    /* Send Register address */
     I2C_SendData(I2Cx, (uint8_t) reg);
 
-        /* Wait until TCR flag is set */
+    /* Wait until TCR flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_TCR) == RESET)
     {
@@ -155,10 +155,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t data)
         }
     }
 
-        /* Configure slave address, nbytes, reload, end mode and start or stop generation */
+    /* Configure slave address, nbytes, reload, end mode and start or stop generation */
     I2C_TransferHandling(I2Cx, addr_, 1, I2C_AutoEnd_Mode, I2C_No_StartStop);
 
-        /* Wait until TXIS flag is set */
+    /* Wait until TXIS flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_TXIS) == RESET) {
         if ((i2cTimeout--) == 0) {
@@ -166,10 +166,10 @@ bool i2cWrite(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t data)
         }
     }
 
-        /* Write data to TXDR */
+    /* Write data to TXDR */
     I2C_SendData(I2Cx, data);
 
-        /* Wait until STOPF flag is set */
+    /* Wait until STOPF flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_STOPF) == RESET) {
         if ((i2cTimeout--) == 0) {
@@ -177,7 +177,7 @@ bool i2cWrite(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t data)
         }
     }
 
-        /* Clear STOPF flag */
+    /* Clear STOPF flag */
     I2C_ClearFlag(I2Cx, I2C_ICR_STOPCF);
 
     return true;
@@ -198,10 +198,10 @@ bool i2cRead(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t len, uint8_t*
         }
     }
 
-        /* Configure slave address, nbytes, reload, end mode and start or stop generation */
+    /* Configure slave address, nbytes, reload, end mode and start or stop generation */
     I2C_TransferHandling(I2Cx, addr_, 1, I2C_SoftEnd_Mode, I2C_Generate_Start_Write);
 
-        /* Wait until TXIS flag is set */
+    /* Wait until TXIS flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_TXIS) == RESET) {
         if ((i2cTimeout--) == 0) {
@@ -209,10 +209,10 @@ bool i2cRead(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t len, uint8_t*
         }
     }
 
-        /* Send Register address */
+    /* Send Register address */
     I2C_SendData(I2Cx, (uint8_t) reg);
 
-        /* Wait until TC flag is set */
+    /* Wait until TC flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_TC) == RESET) {
         if ((i2cTimeout--) == 0) {
@@ -220,10 +220,10 @@ bool i2cRead(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t len, uint8_t*
         }
     }
 
-        /* Configure slave address, nbytes, reload, end mode and start or stop generation */
+    /* Configure slave address, nbytes, reload, end mode and start or stop generation */
     I2C_TransferHandling(I2Cx, addr_, len, I2C_AutoEnd_Mode, I2C_Generate_Start_Read);
 
-        /* Wait until all data are received */
+    /* Wait until all data are received */
     while (len) {
         /* Wait until RXNE flag is set */
         i2cTimeout = I2C_LONG_TIMEOUT;
@@ -233,16 +233,16 @@ bool i2cRead(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t len, uint8_t*
             }
         }
 
-                /* Read data from RXDR */
+        /* Read data from RXDR */
         *buf = I2C_ReceiveData(I2Cx);
         /* Point to the next location where the byte read will be saved */
         buf++;
 
-                /* Decrement the read bytes counter */
+        /* Decrement the read bytes counter */
         len--;
     }
 
-        /* Wait until STOPF flag is set */
+    /* Wait until STOPF flag is set */
     i2cTimeout = I2C_LONG_TIMEOUT;
     while (I2C_GetFlagStatus(I2Cx, I2C_ISR_STOPF) == RESET) {
         if ((i2cTimeout--) == 0) {
@@ -250,10 +250,10 @@ bool i2cRead(I2CDevice device, uint8_t addr_, uint8_t reg, uint8_t len, uint8_t*
         }
     }
 
-        /* Clear STOPF flag */
+    /* Clear STOPF flag */
     I2C_ClearFlag(I2Cx, I2C_ICR_STOPCF);
 
-        /* If all operations OK */
+    /* If all operations OK */
     return true;
 }
 
diff --git a/src/main/drivers/compass_ak8975.c b/src/main/drivers/compass_ak8975.c
index c35db1d1f..0d648ecc5 100644
--- a/src/main/drivers/compass_ak8975.c
+++ b/src/main/drivers/compass_ak8975.c
@@ -20,10 +20,12 @@
 
 #include <math.h>
 
-#include "build_config.h"
-
 #include "platform.h"
 
+#ifdef USE_MAG_AK8975
+
+#include "build_config.h"
+
 #include "common/axis.h"
 #include "common/maths.h"
 
@@ -31,7 +33,6 @@
 #include "gpio.h"
 #include "bus_i2c.h"
 
-#include "sensors/boardalignment.h"
 #include "sensors/sensors.h"
 
 #include "sensor.h"
@@ -59,7 +60,7 @@
 #define AK8975_MAG_REG_CNTL         0x0a
 #define AK8975_MAG_REG_ASCT         0x0c // self test
 
-bool ak8975detect(mag_t *mag)
+bool ak8975Detect(mag_t *mag)
 {
     bool ack = false;
     uint8_t sig = 0;
@@ -155,3 +156,4 @@ bool ak8975Read(int16_t *magData)
     ack = i2cWrite(MAG_I2C_INSTANCE, AK8975_MAG_I2C_ADDRESS, AK8975_MAG_REG_CNTL, 0x01); // start reading again
     return true;
 }
+#endif
diff --git a/src/main/drivers/compass_ak8975.h b/src/main/drivers/compass_ak8975.h
index f80e64613..493114cb3 100644
--- a/src/main/drivers/compass_ak8975.h
+++ b/src/main/drivers/compass_ak8975.h
@@ -17,6 +17,6 @@
 
 #pragma once
 
-bool ak8975detect(mag_t *mag);
+bool ak8975Detect(mag_t *mag);
 void ak8975Init(void);
 bool ak8975Read(int16_t *magData);
diff --git a/src/main/drivers/compass_hmc5883l.c b/src/main/drivers/compass_hmc5883l.c
index 68c404d80..3709cc510 100644
--- a/src/main/drivers/compass_hmc5883l.c
+++ b/src/main/drivers/compass_hmc5883l.c
@@ -21,6 +21,9 @@
 #include <math.h>
 
 #include "platform.h"
+
+#ifdef USE_MAG_HMC5883
+
 #include "debug.h"
 
 #include "common/axis.h"
@@ -271,3 +274,4 @@ bool hmc5883lRead(int16_t *magData)
 
     return true;
 }
+#endif
diff --git a/src/main/drivers/inverter.h b/src/main/drivers/inverter.h
index 6ec27ef83..4b9c3fe27 100644
--- a/src/main/drivers/inverter.h
+++ b/src/main/drivers/inverter.h
@@ -28,5 +28,3 @@ void inverterSet(bool on);
 
 void initInverter(void);
 
-
-
diff --git a/src/main/drivers/io.c b/src/main/drivers/io.c
index 980168abb..0ba9d9169 100644
--- a/src/main/drivers/io.c
+++ b/src/main/drivers/io.c
@@ -54,14 +54,14 @@ const struct ioPortDef_s ioPortDefs[] = {
 # endif
 
 const char * const ownerNames[OWNER_TOTAL_COUNT] = {
-	"FREE", "PWM", "PPM", "MOTOR", "SERVO", "SOFTSERIAL", "ADC", "SERIAL", "DEBUG", "TIMER",
-	"SONAR", "SYSTEM", "SPI", "I2C", "SDCARD", "FLASH", "USB", "BEEPER", "OSD",
-	"BARO", "MPU", "INVERTER", "LED STRIP", "LED", "RECEIVER", "TRANSMITTER"
+    "FREE", "PWM", "PPM", "MOTOR", "SERVO", "SOFTSERIAL", "ADC", "SERIAL", "DEBUG", "TIMER",
+    "SONAR", "SYSTEM", "SPI", "I2C", "SDCARD", "FLASH", "USB", "BEEPER", "OSD",
+    "BARO", "MPU", "INVERTER", "LED STRIP", "LED", "RECEIVER", "TRANSMITTER"
 };
 
 const char * const resourceNames[RESOURCE_TOTAL_COUNT] = {
-	"", // NONE
-	"IN", "OUT", "IN / OUT", "TIMER","UART TX","UART RX","UART TX/RX","EXTI","SCL",
+    "", // NONE
+    "IN", "OUT", "IN / OUT", "TIMER","UART TX","UART RX","UART TX/RX","EXTI","SCL",
     "SDA", "SCK","MOSI","MISO","CS","BATTERY","RSSI","EXT","CURRENT"
 };
 
diff --git a/src/main/drivers/light_ws2811strip.c b/src/main/drivers/light_ws2811strip.c
index 05f099892..6c8f2bb18 100644
--- a/src/main/drivers/light_ws2811strip.c
+++ b/src/main/drivers/light_ws2811strip.c
@@ -30,6 +30,8 @@
 
 #include <platform.h>
 
+#ifdef LED_STRIP
+
 #include "build_config.h"
 
 #include "common/color.h"
@@ -37,8 +39,6 @@
 #include "drivers/dma.h"
 #include "drivers/light_ws2811strip.h"
 
-#ifdef LED_STRIP
-
 uint8_t ledStripDMABuffer[WS2811_DMA_BUFFER_SIZE];
 volatile uint8_t ws2811LedDataTransferInProgress = 0;
 
diff --git a/src/main/drivers/light_ws2811strip_stm32f10x.c b/src/main/drivers/light_ws2811strip_stm32f10x.c
index b4a9b5426..4b588a0c9 100644
--- a/src/main/drivers/light_ws2811strip_stm32f10x.c
+++ b/src/main/drivers/light_ws2811strip_stm32f10x.c
@@ -20,6 +20,8 @@
 
 #include <platform.h>
 
+#ifdef LED_STRIP
+
 #include "common/color.h"
 #include "drivers/light_ws2811strip.h"
 #include "nvic.h"
@@ -27,8 +29,6 @@
 #include "dma.h"
 #include "timer.h"
 
-#ifdef LED_STRIP
-
 static IO_t ws2811IO = IO_NONE;
 bool ws2811Initialised = false;
 
diff --git a/src/main/drivers/light_ws2811strip_stm32f30x.c b/src/main/drivers/light_ws2811strip_stm32f30x.c
index 722dd9a2e..8379188f9 100644
--- a/src/main/drivers/light_ws2811strip_stm32f30x.c
+++ b/src/main/drivers/light_ws2811strip_stm32f30x.c
@@ -20,6 +20,8 @@
 
 #include <platform.h>
 
+#ifdef LED_STRIP
+
 #include "io.h"
 #include "nvic.h"
 
@@ -29,8 +31,6 @@
 #include "rcc.h"
 #include "timer.h"
 
-#ifdef LED_STRIP
-
 #ifndef WS2811_PIN
 #define WS2811_PIN                      PB8 // TIM16_CH1
 #define WS2811_TIMER                    TIM16
diff --git a/src/main/drivers/light_ws2811strip_stm32f4xx.c b/src/main/drivers/light_ws2811strip_stm32f4xx.c
index e8676e2cd..63bcd9cee 100644
--- a/src/main/drivers/light_ws2811strip_stm32f4xx.c
+++ b/src/main/drivers/light_ws2811strip_stm32f4xx.c
@@ -20,6 +20,8 @@
 
 #include "platform.h"
 
+#ifdef LED_STRIP
+
 #include "common/color.h"
 #include "light_ws2811strip.h"
 #include "nvic.h"
@@ -29,8 +31,6 @@
 #include "rcc.h"
 #include "timer.h"
 
-#ifdef LED_STRIP
-
 #if !defined(WS2811_PIN)
 #define WS2811_PIN                      PA0
 #define WS2811_TIMER                    TIM5
diff --git a/src/main/drivers/pwm_mapping.c b/src/main/drivers/pwm_mapping.c
index 3cec1ab3e..3f88e3a47 100755
--- a/src/main/drivers/pwm_mapping.c
+++ b/src/main/drivers/pwm_mapping.c
@@ -89,7 +89,6 @@ pwmOutputConfiguration_t *pwmGetOutputConfiguration(void)
 
 pwmOutputConfiguration_t *pwmInit(drv_pwm_config_t *init)
 {
-    int i = 0;
     const uint16_t *setup;
 
 #ifndef SKIP_RX_PWM_PPM
@@ -99,6 +98,7 @@ pwmOutputConfiguration_t *pwmInit(drv_pwm_config_t *init)
     memset(&pwmOutputConfiguration, 0, sizeof(pwmOutputConfiguration));
   
     // this is pretty hacky shit, but it will do for now. array of 4 config maps, [ multiPWM multiPPM airPWM airPPM ]
+    int i = 0;
     if (init->airplane)
         i = 2; // switch to air hardware config
     if (init->usePPM || init->useSerialRx)
@@ -177,8 +177,8 @@ pwmOutputConfiguration_t *pwmInit(drv_pwm_config_t *init)
 #ifdef SONAR
         if (init->useSonar &&
             (
-                timerHardwarePtr->tag == init->sonarConfig.triggerTag ||
-                timerHardwarePtr->tag == init->sonarConfig.echoTag
+                timerHardwarePtr->tag == init->sonarIOConfig.triggerTag ||
+                timerHardwarePtr->tag == init->sonarIOConfig.echoTag
             )) {
             continue;
         }
diff --git a/src/main/drivers/pwm_mapping.h b/src/main/drivers/pwm_mapping.h
index 5a3f402e9..29a5d02f1 100644
--- a/src/main/drivers/pwm_mapping.h
+++ b/src/main/drivers/pwm_mapping.h
@@ -68,9 +68,10 @@ typedef struct drv_pwm_config_s {
     uint16_t motorPwmRate;
     uint16_t idlePulse;  // PWM value to use when initializing the driver. set this to either PULSE_1MS (regular pwm),
                          // some higher value (used by 3d mode), or 0, for brushed pwm drivers.
-    sonarIOConfig_t sonarConfig;
+    sonarIOConfig_t sonarIOConfig;
 } drv_pwm_config_t;
 
+
 enum {
     MAP_TO_PPM_INPUT = 1,
     MAP_TO_PWM_INPUT,
@@ -136,4 +137,5 @@ extern const uint16_t airPPM_BP6[];
 extern const uint16_t airPWM_BP6[];
 #endif
 
+pwmOutputConfiguration_t *pwmInit(drv_pwm_config_t *init);
 pwmOutputConfiguration_t *pwmGetOutputConfiguration(void);
diff --git a/src/main/drivers/pwm_output.c b/src/main/drivers/pwm_output.c
index 44504f680..f470137a7 100644
--- a/src/main/drivers/pwm_output.c
+++ b/src/main/drivers/pwm_output.c
@@ -71,12 +71,11 @@ static void pwmOCConfig(TIM_TypeDef *tim, uint8_t channel, uint16_t value, uint8
     TIM_OCStructInit(&TIM_OCInitStructure);
     TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
     if (output & TIMER_OUTPUT_N_CHANNEL) {
-      TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
-      TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
-    }
-    else {
-      TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
-      TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
+        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Disable;
+        TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
+    } else {
+        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
+        TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;
     }
     TIM_OCInitStructure.TIM_Pulse = value;
     TIM_OCInitStructure.TIM_OCPolarity = (output & TIMER_OUTPUT_INVERTED) ? TIM_OCPolarity_High : TIM_OCPolarity_Low;
@@ -175,7 +174,7 @@ void pwmWriteMotor(uint8_t index, uint16_t value)
 
 void pwmShutdownPulsesForAllMotors(uint8_t motorCount)
 {
-    for(int index = 0; index < motorCount; index++){
+    for (int index = 0; index < motorCount; index++) {
         // Set the compare register to 0, which stops the output pulsing if the timer overflows
         *motors[index]->ccr = 0;
     }
@@ -197,13 +196,13 @@ void pwmCompleteOneshotMotorUpdate(uint8_t motorCount)
         bool overflowed = false;
         // If we have not already overflowed this timer
         for (int j = 0; j < index; j++) {
-          if (motors[j]->tim == motors[index]->tim) {
-            overflowed = true;
-            break;
-          }
+            if (motors[j]->tim == motors[index]->tim) {
+                overflowed = true;
+                break;
+            }
         }
         if (!overflowed) {
-          timerForceOverflow(motors[index]->tim);
+            timerForceOverflow(motors[index]->tim);
         }
         // Set the compare register to 0, which stops the output pulsing if the timer overflows before the main loop completes again.
         // This compare register will be set to the output value on the next main loop.
diff --git a/src/main/drivers/serial_softserial.c b/src/main/drivers/serial_softserial.c
index 51cdeb293..d8fafdf78 100644
--- a/src/main/drivers/serial_softserial.c
+++ b/src/main/drivers/serial_softserial.c
@@ -470,14 +470,16 @@ bool isSoftSerialTransmitBufferEmpty(serialPort_t *instance)
 
 const struct serialPortVTable softSerialVTable[] = {
     {
-        softSerialWriteByte,
-        softSerialRxBytesWaiting,
-        softSerialTxBytesFree,
-        softSerialReadByte,
-        softSerialSetBaudRate,
-        isSoftSerialTransmitBufferEmpty,
-        softSerialSetMode,
+        .serialWrite = softSerialWriteByte,
+        .serialTotalRxWaiting = softSerialRxBytesWaiting,
+        .serialTotalTxFree = softSerialTxBytesFree,
+        .serialRead = softSerialReadByte,
+        .serialSetBaudRate = softSerialSetBaudRate,
+        .isSerialTransmitBufferEmpty = isSoftSerialTransmitBufferEmpty,
+        .setMode = softSerialSetMode,
         .writeBuf = NULL,
+        .beginWrite = NULL,
+        .endWrite = NULL
     }
 };
 
diff --git a/src/main/drivers/system.h b/src/main/drivers/system.h
index c6d58aa74..105a584c4 100644
--- a/src/main/drivers/system.h
+++ b/src/main/drivers/system.h
@@ -67,5 +67,3 @@ void unregisterExtiCallbackHandler(IRQn_Type irqn, extiCallbackHandlerFunc *fn);
 
 extern uint32_t cachedRccCsrValue;
 
-
-
diff --git a/src/main/flight/failsafe.h b/src/main/flight/failsafe.h
index 501c16845..d166e1c36 100644
--- a/src/main/flight/failsafe.h
+++ b/src/main/flight/failsafe.h
@@ -70,6 +70,8 @@ typedef struct failsafeState_s {
     failsafeRxLinkState_e rxLinkState;
 } failsafeState_t;
 
+struct rxConfig_s;
+void failsafeInit(struct rxConfig_s *intialRxConfig, uint16_t deadband3d_throttle);
 void useFailsafeConfig(failsafeConfig_t *failsafeConfigToUse);
 
 void failsafeStartMonitoring(void);
diff --git a/src/main/flight/imu.h b/src/main/flight/imu.h
index 6dc0a1f6b..94b361fcf 100644
--- a/src/main/flight/imu.h
+++ b/src/main/flight/imu.h
@@ -88,3 +88,4 @@ int16_t imuCalculateHeading(t_fp_vector *vec);
 
 void imuResetAccelerationSum(void);
 void imuUpdateAcc(rollAndPitchTrims_t *accelerometerTrims);
+void imuInit(void);
diff --git a/src/main/flight/mixer.h b/src/main/flight/mixer.h
index b76aafa1b..bf1293e73 100644
--- a/src/main/flight/mixer.h
+++ b/src/main/flight/mixer.h
@@ -206,10 +206,15 @@ void mixerUseConfigs(
 void writeAllMotors(int16_t mc);
 void mixerLoadMix(int index, motorMixer_t *customMixers);
 #ifdef USE_SERVOS
+void mixerInit(mixerMode_e mixerMode, motorMixer_t *customMotorMixers, servoMixer_t *customServoMixers);
 void servoMixerLoadMix(int index, servoMixer_t *customServoMixers);
 void loadCustomServoMixer(void);
 int servoDirection(int servoIndex, int fromChannel);
+#else
+void mixerInit(mixerMode_e mixerMode, motorMixer_t *customMotorMixers);
 #endif
+struct pwmOutputConfiguration_s;
+void mixerUsePWMOutputConfiguration(struct pwmOutputConfiguration_s *pwmOutputConfiguration, bool use_unsyncedPwm);
 void mixerResetDisarmedMotors(void);
 void mixTable(void *pidProfilePtr);
 void syncMotors(bool enabled);
diff --git a/src/main/flight/navigation.h b/src/main/flight/navigation.h
index 673cf5cfb..8adb9918d 100644
--- a/src/main/flight/navigation.h
+++ b/src/main/flight/navigation.h
@@ -46,6 +46,8 @@ extern int16_t GPS_directionToHome;        // direction to home or hol point in
 
 extern navigationMode_e nav_mode;          // Navigation mode
 
+struct pidProfile_s;
+void navigationInit(gpsProfile_t *initialGpsProfile, struct pidProfile_s *pidProfile);
 void GPS_reset_home_position(void);
 void GPS_reset_nav(void);
 void GPS_set_next_wp(int32_t* lat, int32_t* lon);
diff --git a/src/main/io/display.h b/src/main/io/display.h
index 8149a35ad..5582dc512 100644
--- a/src/main/io/display.h
+++ b/src/main/io/display.h
@@ -35,6 +35,8 @@ typedef enum {
 #endif
 } pageId_e;
 
+struct rxConfig_s;
+void displayInit(struct rxConfig_s *intialRxConfig);
 void updateDisplay(void);
 
 void displayShowFixedPage(pageId_e pageId);
diff --git a/src/main/io/gps.h b/src/main/io/gps.h
index cdb9f66f6..efa0ec32c 100644
--- a/src/main/io/gps.h
+++ b/src/main/io/gps.h
@@ -117,7 +117,8 @@ extern uint8_t GPS_svinfo_cno[16];         // Carrier to Noise Ratio (Signal Str
 #define GPS_DBHZ_MIN 0
 #define GPS_DBHZ_MAX 55
 
-
+struct serialConfig_s;
+void gpsInit(struct serialConfig_s *serialConfig, gpsConfig_t *initialGpsConfig);
 void gpsThread(void);
 bool gpsNewFrame(uint8_t c);
 void updateGpsIndicator(uint32_t currentTime);
diff --git a/src/main/io/serial_cli.h b/src/main/io/serial_cli.h
index d54b04cec..f2ec866a6 100644
--- a/src/main/io/serial_cli.h
+++ b/src/main/io/serial_cli.h
@@ -20,6 +20,8 @@
 
 extern uint8_t cliMode;
 
+struct serialConfig_s;
+void cliInit(struct serialConfig_s *serialConfig);
 void cliProcess(void);
 bool cliIsActiveOnPort(serialPort_t *serialPort);
 
diff --git a/src/main/main.c b/src/main/main.c
index 79e415c1c..6597ea767 100644
--- a/src/main/main.c
+++ b/src/main/main.c
@@ -25,6 +25,7 @@
 #include "common/axis.h"
 #include "common/color.h"
 #include "common/maths.h"
+#include "common/printf.h"
 
 #include "drivers/nvic.h"
 
@@ -61,6 +62,7 @@
 #endif
 
 #include "rx/rx.h"
+#include "rx/spektrum.h"
 
 #include "io/beeper.h"
 #include "io/serial.h"
@@ -72,6 +74,8 @@
 #include "io/ledstrip.h"
 #include "io/display.h"
 #include "io/asyncfatfs/asyncfatfs.h"
+#include "io/serial_cli.h"
+#include "io/serial_msp.h"
 #include "io/transponder_ir.h"
 #include "io/osd.h"
 #include "io/vtx.h"
@@ -115,28 +119,6 @@ extern uint8_t motorControlEnable;
 serialPort_t *loopbackPort;
 #endif
 
-void printfSupportInit(void);
-void timerInit(void);
-void telemetryInit(void);
-void mspInit(serialConfig_t *serialConfig);
-void cliInit(serialConfig_t *serialConfig);
-void failsafeInit(rxConfig_t *intialRxConfig, uint16_t deadband3d_throttle);
-pwmOutputConfiguration_t *pwmInit(drv_pwm_config_t *init);
-#ifdef USE_SERVOS
-void mixerInit(mixerMode_e mixerMode, motorMixer_t *customMotorMixers, servoMixer_t *customServoMixers);
-#else
-void mixerInit(mixerMode_e mixerMode, motorMixer_t *customMotorMixers);
-#endif
-void mixerUsePWMOutputConfiguration(pwmOutputConfiguration_t *pwmOutputConfiguration, bool use_unsyncedPwm);
-void rxInit(rxConfig_t *rxConfig, modeActivationCondition_t *modeActivationConditions);
-void gpsInit(serialConfig_t *serialConfig, gpsConfig_t *initialGpsConfig);
-void navigationInit(gpsProfile_t *initialGpsProfile, pidProfile_t *pidProfile);
-void imuInit(void);
-void displayInit(rxConfig_t *intialRxConfig);
-void ledStripInit(ledConfig_t *ledConfigsToUse, hsvColor_t *colorsToUse, modeColorIndexes_t *modeColorsToUse, specialColorIndexes_t *specialColorsToUse);
-void spektrumBind(rxConfig_t *rxConfig);
-const sonarHardware_t *sonarGetHardwareConfiguration(currentSensor_e currentSensor);
-void osdInit(void);
 
 typedef enum {
     SYSTEM_STATE_INITIALISING   = 0,
@@ -270,8 +252,8 @@ void init(void)
         const sonarHardware_t *sonarHardware = sonarGetHardwareConfiguration(masterConfig.batteryConfig.currentMeterType);
         if (sonarHardware) {
             pwm_params.useSonar = true;
-            pwm_params.sonarConfig.triggerTag = sonarHardware->triggerTag;
-            pwm_params.sonarConfig.echoTag = sonarHardware->echoTag;
+            pwm_params.sonarIOConfig.triggerTag = sonarHardware->triggerTag;
+            pwm_params.sonarIOConfig.echoTag = sonarHardware->echoTag;
         }
     }
 #endif
diff --git a/src/main/rx/rx.h b/src/main/rx/rx.h
index 60625f608..1200e5e8f 100644
--- a/src/main/rx/rx.h
+++ b/src/main/rx/rx.h
@@ -143,10 +143,11 @@ typedef struct rxRuntimeConfig_s {
 
 extern rxRuntimeConfig_t rxRuntimeConfig;
 
-void useRxConfig(rxConfig_t *rxConfigToUse);
-
 typedef uint16_t (*rcReadRawDataPtr)(rxRuntimeConfig_t *rxRuntimeConfig, uint8_t chan);        // used by receiver driver to return channel data
 
+struct modeActivationCondition_s;
+void rxInit(rxConfig_t *rxConfig, struct modeActivationCondition_s *modeActivationConditions);
+void useRxConfig(rxConfig_t *rxConfigToUse);
 void updateRx(uint32_t currentTime);
 bool rxIsReceivingSignal(void);
 bool rxAreFlightChannelsValid(void);
diff --git a/src/main/rx/spektrum.h b/src/main/rx/spektrum.h
index 82989ea55..5481bdebc 100644
--- a/src/main/rx/spektrum.h
+++ b/src/main/rx/spektrum.h
@@ -21,3 +21,6 @@
 #define SPEKTRUM_SAT_BIND_MAX 10
 
 uint8_t spektrumFrameStatus(void);
+struct rxConfig_s;
+void spektrumBind(struct rxConfig_s *rxConfig);
+
diff --git a/src/main/sensors/battery.h b/src/main/sensors/battery.h
index 9d6afab5d..f459a3bcc 100644
--- a/src/main/sensors/battery.h
+++ b/src/main/sensors/battery.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-#include "rx/rx.h"
 #include "common/maths.h"
 
 #ifndef VBAT_SCALE_DEFAULT
@@ -75,7 +74,8 @@ void updateBattery(void);
 void batteryInit(batteryConfig_t *initialBatteryConfig);
 batteryConfig_t *batteryConfig;
 
-void updateCurrentMeter(int32_t lastUpdateAt, rxConfig_t *rxConfig, uint16_t deadband3d_throttle);
+struct rxConfig_s;
+void updateCurrentMeter(int32_t lastUpdateAt, struct rxConfig_s *rxConfig, uint16_t deadband3d_throttle);
 int32_t currentMeterToCentiamps(uint16_t src);
 
 fix12_t calculateVbatPidCompensation(void);
diff --git a/src/main/sensors/initialisation.c b/src/main/sensors/initialisation.c
index 38d81a1f4..bb46059ac 100755
--- a/src/main/sensors/initialisation.c
+++ b/src/main/sensors/initialisation.c
@@ -537,7 +537,7 @@ retry:
 
         case MAG_AK8975:
 #ifdef USE_MAG_AK8975
-            if (ak8975detect(&mag)) {
+            if (ak8975Detect(&mag)) {
 #ifdef MAG_AK8975_ALIGN
                 magAlign = MAG_AK8975_ALIGN;
 #endif
diff --git a/src/main/sensors/sonar.h b/src/main/sensors/sonar.h
index be49afb7b..0c0849e32 100644
--- a/src/main/sensors/sonar.h
+++ b/src/main/sensors/sonar.h
@@ -17,12 +17,16 @@
 
 #pragma once
 
+#include "sensors/battery.h"
+
 #define SONAR_OUT_OF_RANGE (-1)
 
 extern int16_t sonarMaxRangeCm;
 extern int16_t sonarCfAltCm;
 extern int16_t sonarMaxAltWithTiltCm;
 
+struct sonarHardware_s;
+const struct sonarHardware_s *sonarGetHardwareConfiguration(currentSensor_e currentSensor);
 void sonarInit(void);
 void sonarUpdate(void);
 int32_t sonarRead(void);
diff --git a/src/main/telemetry/telemetry.h b/src/main/telemetry/telemetry.h
index b4585e5fc..b61aa68bd 100644
--- a/src/main/telemetry/telemetry.h
+++ b/src/main/telemetry/telemetry.h
@@ -46,6 +46,7 @@ typedef struct telemetryConfig_s {
     uint8_t hottAlarmSoundInterval;
 } telemetryConfig_t;
 
+void telemetryInit(void);
 bool telemetryCheckRxPortShared(serialPortConfig_t *portConfig);
 extern serialPort_t *telemetrySharedPort;