Enable USB Serial (FTDI230X / Palette 2) on Flashforge Adventurer 5M (Pro)

Background

I replaced my original 3D printer with a smaller Flashforge Adventurer 5M Pro, but the Mosaic Palette 2 wasn’t connecting when plugged into the printer’s USB. dmesg showed the device was seen but not mounted, indicating the kernel was missing the USB-to-serial driver module.

I spent time trying to compile the modules using the kernel.org sources, but got “Oops” errors when enabling them on the printer. A forum comment pointed to a “Tina Linux” kernel source which supposedly worked for their own use case (compiling the wifi module).

Sadly, the comment was from 2024 and the repo was gone, but I found a copy and cloned it. On to the solution!

Prerequisites

A Debian/Ubuntu (or compatible) VM with root or sudo privileges
Network access to the printer (for scp)
Enough storage and CPU to compile kernel modules in a timely manner
Basic familiarity with make, scp, insmod, and editing files on the printer
In theory these commands won’t brick the printer, but do these steps at your own risk

Solution

1 – Start with a fresh Debian (or your favorite distro) VM with the basic configuration

2 – Update Packages

3 – Install build tools

apt-get install -y build-essential git wget xz-utils bc bison flex libssl-dev rsync file python3 pkg-config

4 – Setup Linaro 7.1 Toolchain

cd /root
mkdir -p toolchains
cd toolchains
wget https://releases.linaro.org/components/toolchain/binaries/7.4-2019.02/arm-linux-gnueabi/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabi.tar.xz
tar -xf gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabi.tar.xz
export CROSS=/root/toolchains/gcc-linaro-7.4.1-2019.02-x86_64_arm-linux-gnueabi/bin/arm-linux-gnueabi-

5 – Get the correct kernel source

cd /root
git clone https://github.com/cfelicio/tina-linux-5.4.git linux-5.4.61-tina
cd linux-5.4.61-tina
rm -rf .git

The Tina Linux source matches the kernel used on the printer (5.4.61).

6 – On the printer: get current kernel info and config

uname -a
zcat /proc/config.gz > printer.config

7 – Back on the VM: copy the printer.config file from the printer via SCP

scp -O [email protected]:/root/printer.config /root/printer.config

8 – Copy printer.config into the kernel tree as .config

cd /root/linux-5.4.61-tina
cp /root/printer.config .config

9 – The actual build process

chmod +x scripts/config
./scripts/config --disable CONFIG_LOCALVERSION_AUTO
./scripts/config --set-str CONFIG_LOCALVERSION ""
make ARCH=arm CROSS_COMPILE="$CROSS" olddefconfig

# Enable drivers as modules
./scripts/config --module CONFIG_USB_SERIAL
./scripts/config --module CONFIG_USB_SERIAL_FTDI_SIO

# Re-resolve dependencies and prep build
make ARCH=arm CROSS_COMPILE="$CROSS" olddefconfig
make ARCH=arm CROSS_COMPILE="$CROSS" modules_prepare

# Build only the subdir to save time
make -j"$(nproc)" ARCH=arm CROSS_COMPILE="$CROSS" M=drivers/usb/serial modules

(If you see warnings, the build & zImage sequence below avoids them), but this is not crucial

make -j"$(nproc)" ARCH=arm CROSS_COMPILE="$CROSS" zImage modules
make -j"$(nproc)" ARCH=arm CROSS_COMPILE="$CROSS" M=drivers/usb/serial modules

10 – Verify the modules were built successfully and match your printer’s kernel (from step 6)

file drivers/usb/serial/usbserial.ko
modinfo -F vermagic drivers/usb/serial/usbserial.ko
modinfo -F vermagic drivers/usb/serial/ftdi_sio.ko

vermagic must match the running kernel version (e.g., 5.4.61). If it doesn’t, you will get invalid module format errors.

11 – Copy the modules over to the printer via SCP

scp -O drivers/usb/serial/ftdi_sio.ko [email protected]:/root/ftdi_sio.ko
scp -O drivers/usb/serial/usbserial.ko [email protected]:/root/usbserial.ko

12 – Load the modules and review dmesg for any errors

insmod usbserial.ko
insmod ftdi_sio.ko

13 – Plug in your Palette 2. It should show up under ttyUSB0, indicating success!

14 – If everything worked well and you want to make the change permanent, move the ko files to your modules, and have them auto start

mv ftdi_sio.ko /lib/modules/5.4.61
mv usbserial.ko /lib/modules/5.4.61
vi /etc/init.d/S50usbserialmod
chmod 755 /etc/init.d/S50usbserialmod

Insert the following into your startup script:

#!/bin/sh
#
# start usb-serial modules for Palette 2 communication
#

insmod /lib/modules/5.4.61/usbserial.ko
insmod /lib/modules/5.4.61/ftdi_sio.ko

15 – Modify your printer.cfg to include palette2

[palette2]
serial: /dev/ttyUSB0
baud: 115200

Klipper Fix

Despite the connection being successful, I was getting an error when issuing the PALETTE_CONNECT command on Klipper. I opened a PR, but will likely take a while to make it downstream:

https://github.com/Klipper3d/klipper/pull/7085

Internal error on command:”PALETTE_CONNECT”
Internal Error on WebRequest: gcode/script
Traceback (most recent call last):
File “/opt/klipper/klippy/webhooks.py”, line 257, in _process_request
func(web_request)
File “/opt/klipper/klippy/webhooks.py”, line 438, in _handle_script
self.gcode.run_script(web_request.get_str(‘script’))
File “/opt/klipper/klippy/gcode.py”, line 216, in run_script
self._process_commands(script.split(‘\n’), need_ack=False)
File “/opt/klipper/klippy/gcode.py”, line 198, in _process_commands
handler(gcmd)
File “/opt/klipper/klippy/gcode.py”, line 135, in
func = lambda params: origfunc(self._get_extended_params(params))
File “/opt/klipper/klippy/extras/palette2.py”, line 173, in cmd_Connect
self._wait_for_heartbeat()
File “/opt/klipper/klippy/extras/palette2.py”, line 225, in _wait_for_heartbeat
currTs – SETUP_TIMEOUT) and startTs > (
TypeError: ‘<‘ not supported between instances of ‘NoneType’ and ‘float’
MCU ‘mcu’ shutdown: Command request

File location (might be present on multiple places on your printer, use find): klipper/klippy/extras/palette2.py

def _wait_for_heartbeat(self):
    startTs = self.reactor.monotonic()
    currTs = startTs
    while True:
        currTs = self.reactor.pause(currTs + 1.0)
        if (
            self.heartbeat is not None
            and self.heartbeat >= (currTs - SETUP_TIMEOUT)
        ):
            break
        if currTs - startTs > SETUP_TIMEOUT:
            self.signal_disconnect = True
            raise self.printer.command_error(
                "No response from Palette 2"
            )

Bonus: Building other modules

This guide is specifically designed for the Palette 2 with the FT230X USB to Serial chip, but you can use the same pattern for any in-tree module that you might need

1- Find the Kconfig symbol and path and grep the kernel tree for your driver (example for the CH341):

grep -R "config USB_SERIAL_CH341" -n .

#Enable the config symbol
./scripts/config --module CONFIG_USB_SERIAL_CH341

make ARCH=arm CROSS_COMPILE="$CROSS" olddefconfig
make ARCH=arm CROSS_COMPILE="$CROSS" modules_prepare

#Build the module
make -j"$(nproc)" ARCH=arm CROSS_COMPILE="$CROSS" M=drivers/usb/serial modules

For other classes:
- CDC ACM: CONFIG_USB_ACM; path: M=drivers/usb/class
- PL2303: CONFIG_USB_SERIAL_PL2303; path: M=drivers/usb/serial
- CH341: CONFIG_USB_SERIAL_CH341; path: M=drivers/usb/serial
- UVC camera: CONFIG_USB_VIDEO_CLASS; path: M=drivers/media/usb/uvc
Install to the printer and insmod in dependency order (core first, then subdriver). Examples:
- For serial: usbserial.ko before subdrivers (ftdi_sio.ko, pl2303.ko, ch341.ko)
- For USB storage: usbcore/usb-common dependencies load before storage class modules

Common failure modes and fixes:

Invalid module format; version magic ‘5.4.61+ …’ should be ‘5.4.61 …’
- Remove .git from kernel source, disable CONFIG_LOCALVERSION_AUTO, set CONFIG_LOCALVERSION=””
Invalid module format without details
- Verify uname -r is 5.4.61; your .ko vermagic must be 5.4.61 exactly
Built with wrong ABI/toolchain
- Use the vendor toolchain (Linaro 7.4.1 arm-linux-gnueabi-). Rebuild modules with that cross-compiler.

Conclusion

After all this work, you get to print with multiple colors. Yay! If you want to take the easy road, I have the modules pre-compiled here, but no guarantees it will work for your specific printer:

http://carlosfelic.io/5.4.61modules/modules.zip