Add instructions to erase flash settings with DFU

README.md

@@ -65,7 +65,7 @@ On a Windows machine install [st.com](https://st.com) DfuSe USB device firmware
 - cycle power to leave DFU update mode
 
 ### Erasing Flash Settings
-The flash settings are stored in the last flash sector(ID: 11) of bank 0 of stm32f405. With JTAG/SWD adapter connected, you can erase the flash settings without erasing the firmware with the following commands. You may find it useful if you have set the wrong IP settings.
+The flash settings are stored in the last flash sector(ID: 11) of bank 0 of stm32f405. You can erase it with JTAG/SWD adapter or by putting the device in Dfu mode. You may find it useful if you have set network settings incorrectly.
 
 With JTAG/SWD adapter connected, issue the following command:
 
@@ -73,6 +73,12 @@ With JTAG/SWD adapter connected, issue the following command:
 openocd -f interface/stlink.cfg -f target/stm32f4x.cfg -c "flash init; init; halt; flash erase_sector 0 11 last; reset; exit"
 ```
 
+With STM32 in DFU Mode, connect the USB Type C cable and then issue the following command:
+
+```
+dfu-util -a 0 -s 0x080E0000:leave -D erase_flash_settings.bin
+```
+
 ### OpenOCD
 ```shell
 openocd -f interface/stlink.cfg -f target/stm32f4x.cfg -c "program target/thumbv7em-none-eabihf/debug/kirdy verify reset; exit"