Using a Ikea Zigbee LED Dimmer as a PWM dimming source for another LED driver

[Garywoo]

I have a LED ceiling panel light, and I'm trying to build a Zigbee controller for a PWM dimmable constant current LED driver, in order to dim it for use at my workbench.

I have an old Ikea Tradfri LED driver lying around, and I knew that inside there were 2 distinct PCBs:



The 24v power supply board is on the right in the picture above, and the Zigbee dimmer board is on the left. The power supply board wasn't going to be suitable for my light panel, as the Ikea driver is constant voltage, so I'm not using it in this project.

The Zigbee dimmer part consists of a PCB to handle the LED dimming, and a white daughter board containing the Zigbee radio module and microcontroller. Here's a picture of the underside of the dimmer board:



These modules have been fairly well documented, and I was able to locate the PWM output pin of the Zigbee module from information posted in this instructable.

I purchased this dimmable constant current LED driver to power my light panel. It accepts a few different forms of dimming control via the dim+/- inputs: PWM, 0-10v, and Resistance.

I wired up the light panel to the driver, and then wired the PWM output from the Zigbee module to dim+ on the LED driver, and GND to dim-. I powered the Ikea module with 12v from an external supply, but ultimately plan to use the auxiliary 12v supply from the LED driver.

When I turn on the AC to the LED driver, the light panel works and can be dimmed by controlling the Zigbee module, however the dimming seems to be somewhat offset. The driver output only turns on at about 40% brightness of the Zigbee module, and at 100% it's only drawing 640mA out of the available 750mA, which it should draw at full brightness.

For what it's worth, I found this on the PWM specs of the Ikea module

How can I get proper dimming control using the parts I have? Do I need adjust the PWM voltage level like in the instructable, or is the PWM output of the Ikea module just not the right frequency to work with the LED driver I have?