[HACK] Updated - 5v DC Zigbee module from Sengled BR30

I've always wanted to hack a Zigbee lightbulb, but have hesitated for a couple of reasons:

  • I'd have to destroy an otherwise perfectly good bulb
  • Bulbs were often difficult to open
  • Modules were often difficult to extract
  • Posted "How-To" articles couldn't explain how to pair and reset the separated Zigbee modules

While shopping Lowe's Black Friday deals, I came across some Sengled BR30 Zigbee bulbs on clearance for $5.99 CAD. Now, I have no fixtures in my home that use BR30 bulbs, but I figured if the incandescent bulbs in my deck light ever decided to die (They've been going for the 19 years I've owned this house, who knows how long before that), then I would remove the smart switch and use these in their place.

To my shock, these non-repeating Zigbee HA bulbs, that can be directly paired to Hubitat Elevation with no ill effect on the Zigbee network, actually rang up at $3 CAD per bulb! So of course I went back and grabbed more! :rofl: And at this price, I had no reservations against potentially destroying at lease one bulb for the sake of exploration. :wink:

To my surprise and delight, these bulbs are incredibly easy to hack. I mean, really easy. After figuring out what was required, I can open the bulb and extract the Zigbee HA module in less that 3 minutes. What's even better is that it can be driven by a standard 5v DC source, and you can trigger a solid state relay, allowing you to close dry contacts for just about anything.

These modules cannot be battery powered since the original intended use case is mains powered only, they draw 30mA at 5v DC, and so are not suitable for battery powered use, but are easily powered with a common 5v DC USB power adapter.

How to open the bulbs

Recommended tools to make the job easier - (left to right) Diagonal cutters, needle nose pliers, small blade screw driver, small philips screw driver, plastic spudger

  1. Start by using your thumb nail and run it around the circumference of the bulb until you find a spot where there is a small gap between the defuser and the bulb housing. In the two bulbs I've opened so far, this has been very easy to find.

  1. Once a gap is found, insert the blade end of a spudger into the gap.

  1. Work the plastic spudger around the circumference of the diffuser. The sealant/adhesive used on the diffuser is very easily parted from the housing. There are four locations on the diffuser where it also clips to the housing. They will become evident as you begin to pry the diffuser away.

  1. Pry the diffuser away from the housing and you will see how it was sealed and clipped in place

  1. There are now 5 Phillips screws (circled in RED) that must be removed. The 3 in the center hold the LED heat sink to the housing, and the 2 outer screws hold the Zigbee radio antenna to the housing.

  1. Now the Edison screw base must be detached from the bulb housing. The Edison screw is crimped at several points to the housing. Removal is simple, but be careful here and wear gloves so you do not cut yourself. Start by using a small flat head screwdriver to pry up at one of the points where the Edison screw is crimped to the housing. I've found that there will be a slight gap where the neutral wire is sandwiched between the housing and the Edison screw, and this is an easier place to start prying.

  1. Once you get a bit of the Edison screw pried up, you can use needle nose pliers to simply peal it back, and this will release it from the housing.

  1. Now that you have the Edison screw detached, you can see where the HOT wire is soldered to the base of the Edison screw. Simply take diagonal cutters and cut the wire from the base.

  1. Now just lift up on the housing to reveal the LED driver board with the Zigbee HA module attached.

  1. The LED driver and Zigbee module simply unplug from the LEDs and heat sink. You can also attached wires to the module and the LED/heat sink assembly to create your own custom LED fixtures, allowing the LEDs to be mounted flat with ready made screw holes and supplied screws to hold them in place. If you're curious, the output voltage from the driver with the LEDs under load is 70v DC at 100%, and 62.3v DC at 1%.

It is also possible to skip the removal of the module from the driver board, and instead use it attached to the driver board with a 110v relay. AC relays work fine. However since the bulb was originally designed to fade to off, a mechanical relay attached to the driver output connections does not turn off instantly. If you don't need the device you're controlling to turn off instantly either, then this is a viable solution and less expensive to build.

  1. The Zigbee HA module unplugs from the controller board by simply pulling it away. Use the flat end of your spudger to pry up at an angle on the antenna plug from where the wire is attached to it, separating it from the Zigbee module.

  1. The LED array is not glued to the heat sink. It lifts easily away, since once the screws were removed in step 5, the only thing left holding it in place is thermal paste. The paste is messy, but it's not caustic.

  1. With the LED array detached from the heat sink, you can manipulate the antenna plug through the hole to remove it from the heat sink. It won't just easily pull out unfortunately, but I found that once I got it almost out, I could then just press firmly with the flat side of the spudger to force it through the hole without damaging it. However, you must separate the LED array from the heat sink, or the combined thickness will make it impossible to force the antenna plug through the hole.

Don't do this. :point_up: It worked once for me, but when I built the Switchmate project below and tried it again, I came close to causing permanent damaged the antenna connection. I now advise de-soldering the antenna wire from the antenna board, or if you are not going to reuse the LED heatsink, you can likely just use large diagonal cutters to carefully cut through the aluminum without damaging the antenna cable.

  1. Once the antenna is free from the heat sink, re-attach it to the Zigbee HA module. You will not be able to pair or control the Zigbee module if the antenna is not attached to it.

Zigbee HA module operation

Here are the operational pins. These same pins are combined with the circuit ground connection and the reset test point to factory reset the module, and to pair.

From left to right:

5 volt input from your power supply.
The most logical choice is to cut off the micro USB end of a USB power cable, and supply power to the circuit by plugging the USB A connector into the power adapter. These cables seem to come with all kinds of devices today, and typically have just two wires in them, making the task very easy. Quite often I've found that these USB power cables have a RED insulated (+5v DC) and either a BLACK insulated or bare wire (negative or ground wire).

When the module is paired and turned ON either manually (as described here later) or via the Sengled bulb driver, Pin PA6 supplies 3.4v DC. When the module is OFF, there is no power on Pin PA6. This is a high level output, suitable to trigger a solid state relay, but is doesn't have enough current to drive a mechanical relay.

AKA the negative power terminal, but more accurately, it is ground. Ground is where the negative wire from your power supply goes, but when Pin PA6 is briefly shorted to ground following a factory reset, the module will enter pairing mode.

I was able to determine two uses for Pin PB0. The first as mentioned before is that it functions as a manual ON/OFF for the module output. So if the Pin PB0 is closed with the ground pin and held in that state, the module will stop supplying 3.4v DC to Pin PA6. If the connection between PB0 and ground is again opened, this overrides an OFF state that may have been sent from the driver. The module state will now be ON, and 3.4v DC is supplied to Pin PA6. Pin PB0 has a second important function, and that is when contacted briefly to the reset test-point on the Zigbee module 10 times in a row, the module will factory reset.

Zigbee module reset and pairing procedure

  1. Factory reset to prepare for entering pairing mode by shorting Pin PB0 with the reset test point on the board 10 times in a row. I could not just initiate pairing on the module. A factory reset was always required first.

  1. Initiate pairing (always AFTER a factory reset) by briefly shorting Pin PA6 to ground and then PA0 with the RST test point for 2 seconds (updated instruction). I would suggest that you DO NOT leave these pins shorted. It may have no ill effect, or it may damage the module. Remember that PA6, when the module is in the ON state will have 3.4v DC coming from it. I don't know what shorting it to ground for too long might do, but I'm guessing it won't be good. However, briefly is no problem. I tested removing and pairing the module many times in a row, and saw no issue from briefly shorting the connections.


The module will pair with HE as a Sengled Element Classic bulb.

As mentioned from the beginning, the primary use I envision is triggering a solid state relay to close dry contacts. Another possible use is to convert a Bluetooth actuator such as the Switchmate devices. Of course, this would have to be powered by a 5v power adapter, because as I wrote before, the power drain from this module is 30mA. But this is a way to make your own actuators, which can do all sorts of things if you convert the linear motion of the Switchmate by using a lever in place of a light switch.

[UPDATE] See post below for complete instructions

I have a project in mind where I intend to convert two Switchmate devices into Zigbee, and then build an apparatus to press the lock and remote start buttons on an extra car remote, since my vehicle doesn't have the fancy Volvo API.

Another possible use is to convert a Switchmate to Zigbee, and then have that flip a high amperage 110-120v toggle. This would allow for reliable Zigbee ON/OFF control of large loads, without the 15 AMP limits or high cost of most switched outlets.

It's quite easy to have a two-stage relay setup. When the solid state relay engages, you could easily wire it so the 5v DC supply voltage for the Zigbee module will be sent to a 5v DC coil of a mechanical relay, giving you very high amperage contacts for use in a variety of applications.

Basic working schematic - example

Solid State Relays

I have no reason to believe that the Zigbee module on its own cannot trigger a solid state relay that an Arduino can triiger, but full disclosure, I have not tested that yet. I have two solid state relay types on order, One is less expensive, but I don't like it as much because I will have to reverse ON and OFF. That lower cost solid state relay is OFF when the input voltage from the Zigbee module (3.4v) is high, which is the opposite of the Zigbee module ON/OFF state. The more expensive module is ON when the input voltage (3.4v) is high.

Update: I have now tested both solid state relay modules and I prefer the more expensive module because it doesn’t allow any voltage to pass through when it’s OFF. The less expensive module if, for example I pass 5v through it, when it’s OFF, it still passes 1.36v

Just for clarity as well, solid state relays pass a voltage, or do not pass a voltage. So in cases where you need fast response, but also need a no voltage contact, you will need to add a 5v relay to the output of the solid state relay. So when the input voltage from the Zigbee module is high, the solid state relay would pass 5v to a mechanical relay.

Let me know if you try this. With the cost of IKEA plugs being so low right now, I don't think this is a less expensive option. Even at my low cost of $3 CAD per bulb, and if I use a 110v mechanical relay with the original LED driver output, it still would be at least $9 per switch, and that's not an ideal switch either, because it's slow to turn off if I use with the LED driver as the power source.


Where I think this might be a good project, and therefor worth the effort, would be customized lighting fixtures, multi-channel arrays, or situations where a high amperage load needs to be controlled. You can get controllers such as the Sinope 50 AMP load controller, and don't get me wrong, that's a good controller and it measures power consumption too. However, the Sinope controller is $100 USD ($133 CAD). Using this Zigbee module, a solid state relay, and a mechanical relay in combination, I can build a 30 amp controller for around $20 CAD. So having power measurement (which I personally already have with my Aeon HEMs), the $113 price difference does take some of the shine off the Sinope load controller. :wink:


You are fantastic for figuring this all out! I'm particularly interested in this usage, having bought several Switchmates before knowing what I was doing. :slight_smile: I was thinking about trying to put the inside of an ST button under the paddle, but everything was way to small for me to solder (someone better at this than me could probably handle it). This might be a better option, except all I have are A19 Sengleds. Maybe I can find these on sale somewhere in the US...or see if other cheap bulbs I don't care much about anymore (Trådfri? Cree? Though I'd have to keep those on the Hue Bridge, I guess) could work the same.


Excellent write-up, really top notch.
PS- I always feel bad for you guys up north with your high prices, although this time looks like you made out like a bandit- 3 bucks!


This works. No relay needed, but there’s a catch. I couldn’t find a point on the circuit where applying 3V would do anything other than flip-flop the Switchmate, just like pressing the button. This is fine, but it doesn’t tell you the state because you have to pulse the Zigbee module on and off again to move one direction, then on and off again to change direction.

Pulsing 3V from the Zigbee module here will flip the direction of the Switchmate

It’s a little kludgy, but I could add two modules since they’re small enough. Might just have to cut away part of the battery compartment which won’t be used anyway. First module would control, second would capture state by connecting pins PB0 and GND to the common and open (no voltage) contacts of one of the two limit switches in the Switchmate, and then using the on/off state of that module like the open close state of a contact sensor. But that means careful pairing, labelling, and tracking of two Zigbee modules. :crazy_face:


Great write-up and details. Must be a couple of enjoyable days of hacking for sure. I think this will be great for my mag lock project.


Excellent! Thank you!

Is the output from the Zigbee module fixed or is it PWM? I'm guessing it's PWM since it has to control the dimming of the bulb. You just might want to be careful attaching the output to the input of anything else until you figure out if the signal is constant or not. If you don't have an oscilloscope, you could attach a 5v LED (with a resistor of course) to the output from the module. Then if you dim/brighten the "bulb" from Hubitat you can see if the LED gets brighter/dimmer. If it does, well, then you've got a PWM signal. You can minimize the impact of that by having the transition in Hubitat to ASAP and only ever having it on at 100% or off. But you should still be careful about attaching it's output directly to anything until you get an oscilloscope hooked up to it.

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I'm sorry, I don't understand this statement. Why would you need two relays? All relays, mechanical or solid state, either pass current or block current. That's the definition of a relay. How would having two relays in series help you in this case?

This tells me that your zigbee module really isn't "off", instead it's PWM signal is very low. So, your relay is closing and opening rapidly, allowing voltage to pass through. When a relay is off, mechanical or solid state, no current should pass through it. The resistance between COMMON and NO should be infinity when the relay is off in ALL cases. Mechanical or solid state. The reason the PWM signal at a low level will affect a solid state relay is because the reaction time is so much lower than a mechanical relay. A mechanical relay will have a 10-15 millisecond reaction time and a solid state is < 1 millisecond. So, your mechanical relay won't work up enough voltage to trip the relay before the pwm signal is shut off again. Where the solid state will open and close very rapidly.

I would check to see what the resistance is between your NO and COMMON contacts on the relay with the zigbee module hooked up. It might not look like you're getting voltage out but I am willing to bet that you are.

No, that's voltage. But if you are seeing current flow through a relay, then it is not OFF. The impedance between NO and COMMON on a relay that is OFF should be infinity, whether you have a solid state relay or a mechanical relay, agreed?

The whole point is that a relay isn't going to provide electricity to the switch side. It will just connect the NO to COMMON when the coil side is energized. So, this 1.36 V that he's detecting....well, what is the voltage of the device that is connected to the relay? You should not get any voltage leakage from the coil side to the switched side. That would short out whatever the relay was wired to.

Went to Lowe's today. Can't find a single Sengled smart bulb left :sob:. Ended up with 5 Phillips Hue strips for $25 bucks each instead.

@SmartHomePrimer You do realize you have voided the warranty and don't even think about returning it. :wink:


Uhm...i think you need to either reread my statement or google it youself. When the control side is de-energized, the relay does not allow any current to pass through it. AKA, it;s impedance is infinite. How else would it act like a switch?

You're saying that when an SSR is off, it still allows current to flow through it?

He's returning them back to Costco so no problem there.

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But voltage from the control side is not what leaks to the switched side. And in this type of circuit, where we are talking 5v max, 1.3v (or 20%) isn't just leakage. You're just being trying to cover yourself now.

We are talking a 5 v circuit. Not a mains circuit. If I apply 5v to this chip and get 110v out now THAT would be something. We are also talking a DC circuit. So there is no line and neutral.

Ok Ryan I think you are right. Sorry for covering up my mistake.

I would assume it is. Don’t know how they would dim otherwise. There’s almost no current from it (no idea how much though). I don’t own an oscilloscope. I’m not concerned about the solid state relays being fried by it. The output is well below what the ones I listed here can handle. I tried a small 3V relay on the output and it couldn’t close it.

I think it’s just a cheap relay or a bad optocoupler maybe? The other one didn’t do that and the voltage went right to zero.

If you just need a contact closed with no voltage like maybe closing the contact on a remote like I did with my iSmart Alarm remote for HE, you don’t get that. I confirmed that with my multimeter that has a continuity test. This is my previous experience with Solid State Relays too. So adding a mechanical relay would solve that issue. It would be nice if you only needed one relay, but that won’t work for all scenarios, and the output is too weak to close an electromagnetic relay.


Although...it appears Lowe’s will take anything back! :rofl:

And yes, these two Hue Ambient Spots that retail for $51 CAD and the Hue Ambient bulb that retails for $28 CAD were just $1.35 each and all of them work perfectly :smiley:

Why not just use the mechanical relay? Why do you need both? That's the part that I don't understand.

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