feat(swan_r5): blink the LED on startup. set VUSB_SELECT and DISCHARGE to floating to avoid any potential issues with them being outputs.

Author: m-mcgowan

ports/stm/boards/swan_r5/board.c

@@ -33,14 +33,19 @@
 void initialize_discharge_pin(void) {
     /* Initialize the 3V3 discharge to be OFF and the output power to be ON */
     __HAL_RCC_GPIOE_CLK_ENABLE();
+    __HAL_RCC_GPIOC_CLK_ENABLE();
+
     GPIO_InitTypeDef GPIO_InitStruct;
-    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_OD;
+    /* Set the DISCHARGE pin and the USB_DETECT pin to FLOAT */
+    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
     GPIO_InitStruct.Pull = GPIO_NOPULL;
-    GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
     GPIO_InitStruct.Pin = GPIO_PIN_6;
-    HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
-    HAL_GPIO_WritePin(GPIOE, GPIO_PIN_6, GPIO_PIN_SET);
+    HAL_GPIO_Init(GPIOE, &GPIO_InitStruct); /* PE6 DISCHRG */
+    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct); /* PC6 is USB_DETECT */
+
+    /* Turn on the 3V3 regulator */
     GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+    GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
     GPIO_InitStruct.Pin = GPIO_PIN_4;
     HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
     HAL_GPIO_WritePin(GPIOE, GPIO_PIN_4, GPIO_PIN_SET);
@@ -53,14 +58,26 @@ void board_init(void) {
     //  Set tick interrupt priority, default HAL value is intentionally invalid
     //  Without this, USB does not function.
     HAL_InitTick((1UL << __NVIC_PRIO_BITS) - 1UL);
+
+    initialize_discharge_pin();
+
+    __HAL_RCC_GPIOE_CLK_ENABLE();
+    GPIO_InitTypeDef GPIO_InitStruct;
+    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+    GPIO_InitStruct.Pull = GPIO_NOPULL;
+    GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
+    GPIO_InitStruct.Pin = GPIO_PIN_2;
+    HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
+    HAL_GPIO_WritePin(GPIOE, GPIO_PIN_2, GPIO_PIN_SET);
+    HAL_Delay(50);
+    HAL_GPIO_WritePin(GPIOE, GPIO_PIN_2, GPIO_PIN_RESET);
 }
 
 bool board_requests_safe_mode(void) {
     return false;
 }
 
 void reset_board(void) {
-    initialize_discharge_pin();
 }
 
 void board_deinit(void) {