RevPi Core S not detected by RPiBoot for image flash (but Core 3 works)

[Pablo_ros]

Hi everyone,

I’ve been working with a RevPi Core S and I’m trying to update the image from Buster (2022-07-28-revpi-buster.img) to Bullseye in order to use it with CODESYS. I followed all the steps from the official documentation and YouTube tutorial.

The device works perfectly: I can SSH into it, access PiCtory, and configure a DIO module without issues. Everything functions correctly, but I’m stuck at the image reinstallation step.
At the “Installing Checked Image” step, RPiBoot is supposed to detect the device and mount it as a removable drive. However, nothing appears.

What I’ve tried:
- Two different PCs (Windows 10 and Windows 11)
- Multiple micro-USB cables
- With and without device powered on
- No USB hubs; verified USB ports supply 900 mA or more
- Ran RPiBoot as Administrator
- Checked Windows Device Manager — device does not appear at all, not even as an unknown device

However, I tried the Same Cable, same USB port, same host PC, with a RevPi Core 3 and it is detected successfully by RPiBoot.

Also, I read about bridging pins 6 and 7 on the X4 connector to disable the watchdog, but since the Core S only has 4 pins there, as far as I understand, no watchdog is active.

When I run RPiBoot, the console just says: "RPiBOOT: build-date Feb 11 2025 version 20250129~123632 d7b8ca40 Please fit the … Waiting for BCM2835/6/7/2711/2712..."
It just stays there. No new device appears.

Has anyone else had trouble flashing a Core S model like this?

Thanks in advance for your help!
Pablo

[RamiGspo]

Hola Pablo,

Great to hear that you’re working on updating your RevPi!
Just a quick note: Our latest official image is Bookworm, not Bullseye. We strongly recommend using the most up-to-date image to ensure compatibility and best performance. Here’s the link to the latest 64-bit Lite image (April 2025):
250430-revpi-bookworm-arm64-lite

Regarding your issue with RPiBoot, please make sure to follow this exact connection order:
- Disconnect the RevPi from power supply.
- Connect the mini-USB cable to your computer first!
- Then connect the RevPi to the power supply.

After this, you should be able to run RPiBoot successfully.

If you power the device before connecting the USB cable, RPiBoot will not detect the device properly.

After flashing, make sure to do the following:
- Disconnect the power supply from the RevPi.
- Disconnect the mini-USB cable from the RevPi.
- Reconnect the power supply to the RevPi.

If this still doesn’t work under Windows, would you have the possibility to try the process on a Linux environment? Maybe using your other RevPi?

You mentioned that everything works fine on another device - maybe there is not a good contact on the RevPi mini usb port or there may be a hardware problem?
Good luck and let us know how it goes!

Best regards,