Hello everyone,
I’ve been chasing what I originally thought were two separate problems, but after several days of systematic troubleshooting, I now suspect they may be related.
Hardware
-
V1 Jackpot controller
-
ESP32
-
TMC2209 drivers
-
FluidNC v3.9.1
-
LightBurn (current version)
-
Windows 11 laptop
-
USB-C connection
-
Wi-Fi disabled
Machine:
- MPCNC used primarily as a laser.
Problem #1 - Requires RESET before LightBurn connects
Normal startup sequence:
-
Power on the Jackpot.
-
Wait for boot.
-
Connect USB to laptop.
-
Windows immediately recognizes the controller (USB connect sound).
-
Controller always appears as COM3.
-
Start LightBurn.
-
Connect.
At this point LightBurn reports:
Waiting for connection
The COM port opens correctly, but there is no response from the controller.
If I type:
$X
into the console, nothing happens.
If I then press the RESET button on the ESP32,
LightBurn immediately connects and communication begins.
LightBurn then performs the configured homing cycle normally.
Connection after RESET is essentially instantaneous.
Boot log after RESET
Immediately after pressing RESET I receive:
rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
FluidNC v3.9.1
Machine MPCNC
Board Jackpot TMC2209
…
Grbl 3.9 [FluidNC v3.9.1]
ok
Everything appears completely normal after RESET.
Problem #2 - Random job stops
Occasionally LightBurn stops during a job.
The LightBurn console suddenly shows a long stream of:
\xFF\xFF\xFF\xFF\xFF…
The job stops.
In another instance, after the garbage characters I also saw:
The interesting part is that I also see a long stream of 0xFF characters immediately before the ESP32 boot messages after RESET.
That makes me wonder if the controller is rebooting or the serial interface is becoming corrupted.
Troubleshooting already performed
-
Multiple USB cables.
-
Wi-Fi disabled.
-
Jobs split into smaller layers.
-
Windows reboot.
-
OpenBuilds CONTROL removed from Windows Startup.
-
Verified Windows immediately detects USB.
-
COM port is always COM3.
-
$X before RESET receives no response.
-
RESET immediately restores communication.
-
Once connected, the controller behaves normally.
Observations
The ESP32 LEDs illuminate immediately when external machine power is applied.
Windows detects the controller correctly before RESET.
LightBurn successfully opens COM3 before RESET.
The controller simply does not respond until RESET is pressed.
Questions
-
Has anyone seen a Jackpot require RESET before FluidNC will respond over USB?
-
Is this a known issue with FluidNC 3.9.1?
-
Could this indicate an ESP32 startup issue?
-
Has anyone seen repeated
\xFF\xFF\xFF…
characters associated with USB communication or controller resets?
- Would updating FluidNC be the first recommendation, or is there something else I should investigate first?
One other thing I’m planning to test is a USB-C power/signal isolator that blocks USB VBUS while leaving USB data intact, to eliminate any possibility of USB back-powering affecting ESP32 startup.
Any suggestions would be greatly appreciated.
Thanks!
