Hacking A Non-Dimmable LED Fixture

For most of us, the solution to having a non-dimmable LED light bulb but needing a dimmable one is a simple as a drive to the store to get the right kind of bulb. But that seems downright boring, not to mention wasteful, so when [Leo Fernekes] was faced with this problem, he looked for a way to make a non-dimmable bulb dimmable.

To be fair, there was a financial aspect to this hack, too. [Leo] had a bunch of cheap non-dimmable light fixtures he wanted to put to use. He started with a teardown and reverse-engineering of a light strip, which contains little more than LEDs and a small buck converter. His analysis of the circuit led him to a solution for dimming the light: inserting a MOSFET as a shunt around the LEDs. That and the addition of a diode to isolate the LEDs from the current regulator would allow for simple PWM-control of the lights via a microcontroller.

As is typical with these things, there were complications. [Leo] found that a timing problem resulted in flickering LEDs; the fix came from adding a sync circuit that cleverly leveraged a flip-flop inside the PIC16 microcontroller he chose for the circuit. His prototype incorporates these modifications, plus an interface that supports the DALI protocol for architectural lighting control. As always, [Leo] is quick to point out that mixing line voltage into your projects is not without risks, which he takes pains to mitigate. And as is also typical for his projects, [Leo] gives just the right amount of detail to understand the theory behind his design.

Continue reading “Hacking A Non-Dimmable LED Fixture”

TP-Link Router Turned Into A DALI Automated Lighting Controller


The members of Shackspace continue to put up impressive hacks based around the tiny TP-Link routers. This time around [Timm] has shoehorned a DALI controller inside the router case. This is a protocol we don’t remember hearing about before. The Digital Addressable Lighting Interface is a control network for commercial lighting. That way people responsible for taking care of large buildings can shut off all the lights at night (to name just one use). The new room at Shackspace has this style of controllers in its lights.

The two brown wires coming into the router make up the data bus for the DALI system. It connects to the add-on PCB which uses an Atmel AT90PWM316 microcontroller. The chip is specifically designed for DALI networks which made the rest of the project quite easy. It talks to the lights, the router talks to it, bob’s your uncle, and you’ve got network controlled lighting. Get this in a big enough building and you can play some Tetris.

In case you were wondering. Yes, this project has already been added to their TP-Link firmware generator.