diff --git a/src/main/drivers/bus_spi_hal.c b/src/main/drivers/bus_spi_hal.c
index 7cebdf9d66..4da26ffb6a 100644
--- a/src/main/drivers/bus_spi_hal.c
+++ b/src/main/drivers/bus_spi_hal.c
@@ -141,8 +141,14 @@ void spiInitDevice(SPIDevice device)
 
 
 #ifdef SDCARD_SPI_INSTANCE
-    if (spi->dev == SDCARD_SPI_INSTANCE)
-        spi->sdcard = true;
+    if (spi->dev == SDCARD_SPI_INSTANCE) {
+        spi->leadingEdge = true;
+    }
+#endif
+#ifdef RX_SPI_INSTANCE
+    if (spi->dev == RX_SPI_INSTANCE) {
+        spi->leadingEdge = true;
+    }
 #endif
 
     // Enable SPI clock
@@ -157,15 +163,19 @@ void spiInitDevice(SPIDevice device)
     IOConfigGPIOAF(IOGetByTag(spi->sck),  SPI_IO_AF_CFG, spi->af);
     IOConfigGPIOAF(IOGetByTag(spi->miso), SPI_IO_AF_CFG, spi->af);
     IOConfigGPIOAF(IOGetByTag(spi->mosi), SPI_IO_AF_CFG, spi->af);
-    if (spi->nss)
+
+    if (spi->nss) {
         IOConfigGPIOAF(IOGetByTag(spi->nss), SPI_IO_CS_CFG, spi->af);
+    }
 #endif
 #if defined(STM32F10X)
     IOConfigGPIO(IOGetByTag(spi->sck), SPI_IO_AF_SCK_CFG);
     IOConfigGPIO(IOGetByTag(spi->miso), SPI_IO_AF_MISO_CFG);
     IOConfigGPIO(IOGetByTag(spi->mosi), SPI_IO_AF_MOSI_CFG);
-    if (spi->nss)
+
+    if (spi->nss) {
         IOConfigGPIO(IOGetByTag(spi->nss), SPI_IO_CS_CFG);
+    }
 #endif
     SPI_HandleTypeDef Handle;
     Handle.Instance = spi->dev;
@@ -182,7 +192,7 @@ void spiInitDevice(SPIDevice device)
     spiInit.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
     spiInit.TIMode = SPI_TIMODE_DISABLED;
 
-    if (spi->sdcard) {
+    if (spi->leadingEdge) {
         spiInit.CLKPolarity = SPI_POLARITY_LOW;
         spiInit.CLKPhase = SPI_PHASE_1EDGE;
     }
@@ -200,8 +210,9 @@ void spiInitDevice(SPIDevice device)
     if (HAL_SPI_Init(&Handle) == HAL_OK)
     {
         spiHandle[device].Handle = Handle;
-        if (spi->nss)
+        if (spi->nss) {
             IOHi(IOGetByTag(spi->nss));
+        }
     }
 }
 
diff --git a/src/main/drivers/serial_uart_hal.c b/src/main/drivers/serial_uart_hal.c
index fa7f5709d6..1bcd84e64d 100644
--- a/src/main/drivers/serial_uart_hal.c
+++ b/src/main/drivers/serial_uart_hal.c
@@ -262,7 +262,7 @@ void uartStartTxDMA(uartPort_t *s)
     s->txDMAEmpty = false;
 }
 
-uint32_t uartTotalRxBytesWaiting(serialPort_t *instance)
+uint32_t uartTotalRxBytesWaiting(const serialPort_t *instance)
 {
     uartPort_t *s = (uartPort_t*)instance;
 
@@ -283,7 +283,7 @@ uint32_t uartTotalRxBytesWaiting(serialPort_t *instance)
     }
 }
 
-uint32_t uartTotalTxBytesFree(serialPort_t *instance)
+uint32_t uartTotalTxBytesFree(const serialPort_t *instance)
 {
     uartPort_t *s = (uartPort_t*)instance;
 
@@ -318,7 +318,7 @@ uint32_t uartTotalTxBytesFree(serialPort_t *instance)
     return (s->port.txBufferSize - 1) - bytesUsed;
 }
 
-bool isUartTransmitBufferEmpty(serialPort_t *instance)
+bool isUartTransmitBufferEmpty(const serialPort_t *instance)
 {
     uartPort_t *s = (uartPort_t *)instance;
     if (s->txDMAStream)
@@ -371,13 +371,13 @@ void uartWrite(serialPort_t *instance, uint8_t ch)
 
 const struct serialPortVTable uartVTable[] = {
     {
-        uartWrite,
-        uartTotalRxBytesWaiting,
-        uartTotalTxBytesFree,
-        uartRead,
-        uartSetBaudRate,
-        isUartTransmitBufferEmpty,
-        uartSetMode,
+        .serialWrite = uartWrite,
+        .serialTotalRxWaiting = uartTotalRxBytesWaiting,
+        .serialTotalTxFree = uartTotalTxBytesFree,
+        .serialRead = uartRead,
+        .serialSetBaudRate = uartSetBaudRate,
+        .isSerialTransmitBufferEmpty = isUartTransmitBufferEmpty,
+        .setMode = uartSetMode,
         .writeBuf = NULL,
         .beginWrite = NULL,
         .endWrite = NULL,
diff --git a/src/main/drivers/serial_usb_vcp_hal.c b/src/main/drivers/serial_usb_vcp_hal.c
index 4ca91167ec..e81e1bcc19 100644
--- a/src/main/drivers/serial_usb_vcp_hal.c
+++ b/src/main/drivers/serial_usb_vcp_hal.c
@@ -54,13 +54,13 @@ static void usbVcpSetMode(serialPort_t *instance, portMode_t mode)
     // TODO implement
 }
 
-static bool isUsbVcpTransmitBufferEmpty(serialPort_t *instance)
+static bool isUsbVcpTransmitBufferEmpty(const serialPort_t *instance)
 {
     UNUSED(instance);
     return true;
 }
 
-static uint32_t usbVcpAvailable(serialPort_t *instance)
+static uint32_t usbVcpAvailable(const serialPort_t *instance)
 {
     UNUSED(instance);
     uint32_t receiveLength = vcpAvailable();
@@ -73,7 +73,7 @@ static uint8_t usbVcpRead(serialPort_t *instance)
     return vcpRead();
 }
 
-static void usbVcpWriteBuf(serialPort_t *instance, void *data, int count)
+static void usbVcpWriteBuf(serialPort_t *instance, const void *data, int count)
 {
     UNUSED(instance);
 
@@ -83,7 +83,7 @@ static void usbVcpWriteBuf(serialPort_t *instance, void *data, int count)
     }
 
     uint32_t start = millis();
-    uint8_t *p = data;
+    const uint8_t *p = data;
     while (count > 0) {
         uint32_t txed = vcpWrite(p, count);
         count -= txed;
diff --git a/src/main/vcp_hal/usbd_cdc_interface.c b/src/main/vcp_hal/usbd_cdc_interface.c
index f341c25560..a141965cc3 100644
--- a/src/main/vcp_hal/usbd_cdc_interface.c
+++ b/src/main/vcp_hal/usbd_cdc_interface.c
@@ -357,7 +357,7 @@ uint32_t CDC_Send_FreeBytes(void)
  * @param  Len: Number of data to be sent (in bytes)
  * @retval Result of the opeartion: USBD_OK if all operations are OK else VCP_FAIL
  */
-uint32_t vcpWrite(uint8_t* Buf, uint32_t Len)
+uint32_t vcpWrite(const uint8_t* Buf, uint32_t Len)
 {
     uint32_t ptr_head = UserTxBufPtrIn;
     uint32_t ptr_tail = UserTxBufPtrOut;
diff --git a/src/main/vcp_hal/usbd_cdc_interface.h b/src/main/vcp_hal/usbd_cdc_interface.h
index c880e0c71e..18c35408e5 100644
--- a/src/main/vcp_hal/usbd_cdc_interface.h
+++ b/src/main/vcp_hal/usbd_cdc_interface.h
@@ -69,7 +69,7 @@ extern USBD_CDC_ItfTypeDef  USBD_CDC_fops;
 
 uint8_t vcpRead();
 uint8_t vcpAvailable();
-uint32_t vcpWrite(uint8_t* Buf, uint32_t Len);
+uint32_t vcpWrite(const uint8_t* Buf, uint32_t Len);
 uint32_t vcpBaudrate();
 uint8_t vcpIsConnected();
 uint32_t CDC_Send_FreeBytes(void);