Device Firmware Upgrade
To upgrade the firmware of the STM32 microcontroller on your Snickerdoodle, please consult
Additionally, we'll provide a few tips here.
No LED's in DFU mode
The LED pattern seen when booting in to DFU mode varies depending on the version of the firmware booted. Some of the earliest firmware versions do not light the LED's at all.
Various pages suggest that you hold down the Reset button and the Select button together when booting to enter DFU mode. This works for nearly all versions of the firmware, but some pages suggest that this be done for three seconds, others say four or more seconds. This might lead to some confusion.
If your Snickerdoodle is connected to a Win10 machine, you should be able to release those buttons as soon the Windows 10 machine emits the sound that indicates that a USB device has just been plugged in. For most versions of the firmware, that will also be when you see the LED's on the Snickerdoodle flash.
Win10 DfuSeDemo can not find the Snickerdoodle
If you follow the steps in the Firmware User Guide, yet the DfuSeDemo window does not seem to find the Snickerdoodle STM32, you probably need to take some additional steps.
First open up Window's Device Manager. You should see the "STMicroelectronics Virtual COM port (COMxxxx)" device active. If you instead see "STM32 BOOTLOADER" or even "STM32 BOOTLOADER" with a caution symbol, you might not have proper device drivers installed on Windows.
Right click on the "STM32 BOOTLOADER" icon and select "Properties". A new Properties window will appear. If the Driver tab indicates that the driver is not found or not correct, this is probably your problem.
Assuming that you have installed DfuSe, you probably have a DfuSe installation directory at a location like "C:\Program Files (x86)\STMicroelectronics\Software\DfuSe v3.0.6" , and it probably contains the device driver you need.
To resolve this problem, you will need to click on the "Update Drivers" button and then "Browse my computer for drivers". When asked where to search, specify the location of the installation (probably "C:\Program Files (x86)\STMicroelectronics\").