Unsolved LED Connected to fan output blinks on startup

[akhilraju]

Hi all,

I have a Duetwifi+Duex2 setup. I've connected a LED strip to fan 4 on the duex. When I turn on the machine the led turns on for a moment and then turns off. Is there a way to stop it from blinking on startup? Why is it happening?

FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 2.02(RTOS) ELECTRONICS: Duet WiFi 1.02 or later + DueX2 FIRMWARE_DATE: 2018-12-24b1

Thanks in advance .

[dc42]

Added to my list of things to look at. There is already a pulldown resistor on the gate of the fan mosfets on the DueX, so this may just be a feature of the SX1509B chip that drives them.

[akhilraju]

@dc42 Thank you for your reply.

[r123]

I have the same question.

The white LED strip flashes like a strobe: am definitely looking for a fix.

[r123]

Failed to figure it out from the datasheet: it would be fun to put an oscilloscope on various power, pin and gate lines to see the timing of the thing, but much too lazy to take the board out of my printer!