Simucube Service Units in STM DFU Mode

Hi @Mika

We recently have x2 Simucube Serviced units we ordered as replacement for our sims,

We removed packaging and re installed the wires, moved over the old Drive IONI Boards onto the new boards.

1st thing we noticed that the old flashing light sequence would be the same on the new simucube boards and we even tried other IONI Boards with similar results.

This makes me think that the memory flash has stored the code and brings it into the new board, however when using a working Drive IONI device still does not appear in the simucube configator tool.

On Device Manager the board will show up but will read as STM Device in DFU Mode when connecting with the X3 USB port, I have flicked the too tiny switches and swapped to X4 Port to see if i can connect to granite devices configurator tool, but as I can not enable this on simucube firmware, we are not sure what to do.

From readying the wiki documents it has been mentioned that

“ Unused SimuCUBE from the factory will contain a special firmware that will place the device in DFU mode regardless of DIP switch setting. So another reason for persistent DFU mode may be that uploading of main firmware has failed, and the factory default FW is still inside.”

I believe we need to re-install the correct firmware as the device shipped is in DFU Mode and would like step by step instructions on how to do this if possible as both units have the same problem.

Thank You

I have also attached media for your reference

All Simucube 1 boards are shipped without firmware.

You will need to use ST Microelectronics’ supplid DfuSeDemo tool to install the Simucube-bootloader.dfu file into the microcontroller. Then Simucube configuration Tool will find it, and install the Simucube firmware.

Motor configuration is stored on the IONI servo drive, so when you have installed Simucube firmware, you will only need to run the motor configuration wizard by “use IONI settings as-is”.

Steps 3-7 in this section:

Thanks @Mika

Just to clarify

Step 1. Download ST Microelectronics’ supplid DfuSeDemo tool

This Link

Step 2.

Download Simucube Firmware - would this be the correct link?

Screenshot 2022-03-31 at 15.11.32

One I have done these 2 things,

What port should i connect the USB Device to on simucube and do I need to do anything else to prepare the install.

as seen in screen shot would i need to select a specfic file for the Dfu Demo tool to work.


Thats the link to very old beta version.

Simucube firmware is being published in our wiki:

You can just get the latest one.

The X3 USB port, i.e. the left port.

Yes, the file I mentioned in above post.

Hi @Mika

  1. I downloaded the DfuSeDemo tool.

  2. After I downloaded the newest Simucube firmware

  3. I right clicked on the file Simucube boot loader file and select open with DfuSe

But nothing happened, Simucube still shows device in DFU Mode on device manager

Iv never done this before and struggle to work out what I had to do exactly

Iv attached photos for reference, please share guidance


Install the DfuSeDemo tool.

Then launch it from the start menu.

And then follow the instructions in the link I provided.

Thanks @Mika

DFEsu tool is open and the device appears there

I followed the instructions by

  1. Selecting the file

  2. Clicking verify after download

  3. Upload

  4. Leave DFU Mode button selected
    I can hear the PC discount and reconnect the USB device but will still show device in DFU mode

  5. Restart PC

Any suggestions and what to do to resolve, PC is currently on Chrome Remote share so I can send share code if like to see.

Thank you

Pictures for reference

You chose “UPLOAD” button, which read the device memory content to a file. You probably overwrote the Simucube-bootloader.dfu file with the DFU mode thing now. Please unzip a fresh copy of that file from the software package and re-read the instructions.

Hint: in the instructions it clearly says that you must use the Upgrade button, on the right.



Thank you for the clarification,

Yes now Iv re downloaded fresh firmware and uploaded .dfu file and clicked UPGRADE with verify after downloaded selected.

On step #7 there should have been a message to click ok which did not appear but the file did upload successfully.

I then clicked the top button and selected leave DFU mode

But same issue appears of device discounted and reconnect appearing as STM Device in DFU mode on device manager

I have closed the demo tool and restarted PC with same results

I believe the correct firmware is on the board now just need to find way to exit DFU mode



Are you sure you flashed a freshly unzipped Simucube-bootloader.dfu file?


Thank you!

Just to make sure I downloaded a version before the newest the 1.0.37

Soon as I did this it’s successful flashed and was able to disable DFU mode.

Simucube opened and followed the steps but now shows error

Operating Mode: waiting for drive to get ready
E stop Motor Status: Fault Location ID:0

But I believe now the device is connected and talking to each other as it appears on device manager and Simucube sees it also,

Would you be able to suggest next.

Thank you

Images referenced below

What happens if you click “enable ioni usb configuration” and connect to the servo drive via Granity and the other USB port? The status information on the last tab would be of interest.


On location now with the sims and did the above.

I have attached video of THE led lights and each page on granite devices

I also swapped the IONI Board over as they show different messages but both have there faults as seen here,

The wheel feels stiff once Simucube is on,

Please look at media as reference and give suggestions on next step.

Simucube picks up the device just not connect to motor

Thank you

Can you show all data from the fault limits tab (scroll down) and also click the software enable button on the first tab.


As requested

This unit is showing the Feedback Fault which I believe one of the Simucube units you had was showing. Is this the same motor?