Fixed issue with PB10 being set to OUTPUT for use as a USB Disconnect control on boards which do not have the additional USB disconnect hardware e.g. the Blue Pill. Note. Some variants seem to have the disconnect control on another pin, so I did not change those in case they were actually used

Author: rogerclarkmelbourne

STM32F1/cores/maple/libmaple/usb/stm32f1/usb_cdcacm.c

@@ -384,9 +384,13 @@ void usb_cdcacm_enable(gpio_dev *disc_dev, uint8 disc_bit) {
     /* Present ourselves to the host. Writing 0 to "disc" pin must
      * pull USB_DP pin up while leaving USB_DM pulled down by the
      * transceiver. See USB 2.0 spec, section 7.1.7.3. */
-    gpio_set_mode(disc_dev, disc_bit, GPIO_OUTPUT_PP);
-    gpio_write_bit(disc_dev, disc_bit, 0);
-
+	 
+	if (disc_dev!=NULL)
+	{	 
+		gpio_set_mode(disc_dev, disc_bit, GPIO_OUTPUT_PP);
+		gpio_write_bit(disc_dev, disc_bit, 0);
+	}
+	
     /* Initialize the USB peripheral. */
     usb_init_usblib(USBLIB, ep_int_in, ep_int_out);
 }
@@ -395,7 +399,10 @@ void usb_cdcacm_disable(gpio_dev *disc_dev, uint8 disc_bit) {
     /* Turn off the interrupt and signal disconnect (see e.g. USB 2.0
      * spec, section 7.1.7.3). */
     nvic_irq_disable(NVIC_USB_LP_CAN_RX0);
-    gpio_write_bit(disc_dev, disc_bit, 1);
+	if (disc_dev!=NULL)
+	{
+		gpio_write_bit(disc_dev, disc_bit, 1);
+	}
 }
 
 void usb_cdcacm_putc(char ch) {

STM32F1/variants/generic_gd32f103c/board/board.h

@@ -70,8 +70,8 @@
 #define BOARD_JTDO_PIN            19
 #define BOARD_NJTRST_PIN          18
 
-#define BOARD_USB_DISC_DEV        GPIOB
-#define BOARD_USB_DISC_BIT        10
+#define BOARD_USB_DISC_DEV        NULL
+#define BOARD_USB_DISC_BIT        NULL
 
 // Note this needs to match with the PIN_MAP array in board.cpp
 enum {

STM32F1/variants/generic_stm32f103c/board/board.h

@@ -70,8 +70,8 @@
 #define BOARD_JTDO_PIN            19
 #define BOARD_NJTRST_PIN          18
 
-#define BOARD_USB_DISC_DEV        GPIOB
-#define BOARD_USB_DISC_BIT        10
+#define BOARD_USB_DISC_DEV        NULL
+#define BOARD_USB_DISC_BIT        NULL
 
 #define LED_BUILTIN PC13
 

STM32F1/variants/generic_stm32f103r8/board/board.h

@@ -70,8 +70,8 @@
 #define BOARD_JTDO_PIN            19
 #define BOARD_NJTRST_PIN          18
 
-#define BOARD_USB_DISC_DEV        GPIOB
-#define BOARD_USB_DISC_BIT        10
+#define BOARD_USB_DISC_DEV        NULL
+#define BOARD_USB_DISC_BIT        NULL
 
 // Note this needs to match with the PIN_MAP array in board.cpp
 enum {

STM32F1/variants/nucleo_f103rb/board/board.h

@@ -102,11 +102,8 @@
 /**
  * Note: there is no USB in this board.
  */
- // Roger Clark. These USB disconnect pin definitions have been added as a temporary fix in order that the this board compiles
- // following changes to add usb serial to other boards
- // I will remove them when the code in the core usb_serial.cpp has been tidied up so that they are no longer needed.
-#define BOARD_USB_DISC_DEV        GPIOB
-#define BOARD_USB_DISC_BIT        10
+#define BOARD_USB_DISC_DEV        NULL
+#define BOARD_USB_DISC_BIT        NULL
 
 /* Pin aliases: these give the GPIO port/bit for each pin as an
  * enum. These are optional, but recommended. They make it easier to