USB device stack with Nucleo F401RE support. NOTE: the default clock config needs to be changed to in order for USB to work.

Fork of USBDevice by Tomas Cerskus

Slightly modified original USBDevice library to support F401RE.

On F401RE the data pins of your USB connector should be attached to PA12 (D+) and PA11(D-). It is also required to connect the +5V USB line to PA9.

F401RE requires 48MHz clock for USB. Therefore in order for this to work you will need to change the default clock settings:

Clock settings for USB

#include "stm32f4xx_hal.h"

RCC_OscInitTypeDef RCC_OscInitStruct;
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = 16;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
RCC_OscInitStruct.PLL.PLLM = 16;
RCC_OscInitStruct.PLL.PLLN = 336;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV4;
RCC_OscInitStruct.PLL.PLLQ = 7;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
    error("RTC error: LSI clock initialization failed."); 
}

NOTE: Changing the clock frequency might affect the behavior of other libraries. I only tested the Serial library.

UPDATE: Clock settings should not to be changed anymore! Looks like the newer mbed library has the required clock enabled.

Revision:
15:849c0c0f2769
Parent:
1:80ab0d068708
Child:
19:fcb63a105965
--- a/USBSerial/USBSerial.h	Thu Sep 12 14:45:27 2013 +0100
+++ b/USBSerial/USBSerial.h	Tue Nov 05 09:45:23 2013 +0000
@@ -55,7 +55,9 @@
     * @param product_release Your preoduct_release (default: 0x0001)
     *
     */
-    USBSerial(uint16_t vendor_id = 0x1f00, uint16_t product_id = 0x2012, uint16_t product_release = 0x0001): USBCDC(vendor_id, product_id, product_release), buf(128){ };
+    USBSerial(uint16_t vendor_id = 0x1f00, uint16_t product_id = 0x2012, uint16_t product_release = 0x0001): USBCDC(vendor_id, product_id, product_release), buf(128){
+        settingsChangedCallback = 0;
+    };
 
 
     /**
@@ -79,6 +81,22 @@
     * @returns the number of bytes available
     */
     uint8_t available(); 
+
+    /** Determine if there is a character available to read
+     *
+     *  @returns
+     *    1 if there is a character available to read,
+     *    0 otherwise
+     */
+    int readable() { return available() ? 1 : 0; }
+    
+    /** Determine if there is space available to write a character
+     *
+     *  @returns
+     *    1 if there is space to write a character,
+     *    0 otherwise
+     */
+    int writeable() { return 1; } // always return 1, for write operation is blocking
     
     /**
     * Write a block of data. 
@@ -110,19 +128,33 @@
      *
      * @param fptr function pointer
      */
-    void attach(void (*fn)(void)) {
-        if(fn != NULL) {
-            rx.attach(fn);
+    void attach(void (*fptr)(void)) {
+        if(fptr != NULL) {
+            rx.attach(fptr);
         }
     }
 
+    /**
+     * Attach a callback to call when serial's settings are changed.
+     *
+     * @param fptr function pointer
+     */
+    void attach(void (*fptr)(int baud, int bits, int parity, int stop)) {
+        settingsChangedCallback = fptr;
+    }
 
 protected:
     virtual bool EP2_OUT_callback();
+    virtual void lineCodingChanged(int baud, int bits, int parity, int stop){
+        if (settingsChangedCallback) {
+            settingsChangedCallback(baud, bits, parity, stop);
+        }
+    }
 
 private:
     FunctionPointer rx;
     CircBuffer<uint8_t> buf;
+    void (*settingsChangedCallback)(int baud, int bits, int parity, int stop);
 };
 
 #endif