LZW36 - Slight Flicker

I’ve had the issue with all three firmwares so far (stock, 1.34, and 1.36).
I’ve tried the following bulbs, all had the same issue:

Fan info:
Harbor Breeze Crosswinds

I’ll try to get a recording of the blink as well

Eric_Inovelli I have noticed this flicker on both of the fan switches I have installed. I have been quietly following this post in hopes it could be fixed with a firmware update. But, from the sounds of it, its probably not the firmware. Do you want people with this problem to create a ticket so you can keep track of it, or wait till the problem is solved?

Ok good news everyone - the manufacturer has been able to replicate this and the engineers are looking into this. More to come!

@Tccshenkes - great question - let’s wait until we know what the issue is and then once we know, I can reach out to you via PM or provide a link in this thread for anyone experiencing this problem. Our ticketing system isn’t as robust with tracking issues :frowning:


I have the same bulb in each fan and all 3 fans are identical. All 3 fans installed the same day. So I had new bulbs that I had not used before, new fans and new switches all at once.

This is the bulbs I have.

This is the fan

Bump… Any updates? This quick off/on flash is beyond annoying.

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Hey thanks for bumping this – so the long story short of this is that there is an issue with the canopy firmware.

Here’s the analysis from the man, myth and legend @JasonL_Inovelli:

Bulb Flicker issue Cause Analysis:
Because the fan module needs to periodically obtain the current power and save it to the internal flash, when saving to the end of the storage space, it will be erased first and then saved again. The erase operation will forcibly stop all interrupts, causing the MCU to fail to enter the PWM control interrupt. , The zero-crossing detection is interrupted, which will cause the loss of the zero-crossing interruption and the abnormal PWM waveform, which will eventually lead to the problem of occasional bulbs flashing.

Adjust the flash read and write time dynamically according to the brightness level of the device, so that the flash erase time does not cover the zero-crossing interruption time, increase the PWM running time compensation after flash erase occurs, and reduce the impact of flash erase on the PWM waveform; When the zero-crossing interrupt is lost, the software delay is used to generate the zero-crossing point to ensure that the PWM operating waveform will not be lost after the zero-crossing interrupt is lost, and the device can still run according to the predetermined PWM timing.

Jason and I have no clue what that means as it came from the engineer, but the long and the short of it is: When the fan module erases the flash or the power supply is not stable, the PWM output will be unstable which cause the bulb flicker. So they revised the firmware to dynamically adjust the time of flash erase and used the software compensation when the power supply is unstable, to make sure the PWM output is stable

The GIF I used to respond to that was:

So, what we’re going to do is for anyone that is experiencing this issue, we’ll replace the canopy module with the new firmware for you. The manufacturer is working on creating a jig which we can attache to the PCB board to upgrade the firmware.

In other words, we need to procure x amount of units from the manufacturer with the updated firmware and when we receive the old modules from everyone, we can update the firmware via the jig so we can have some extras in stock to replace any further issues.

What does that mean to you? We are working on obtaining the replacements. The manufacturer is working on producing these for us in an emergency use. More to come on when they are available and when we can obtain the jig.


JasonL’s diagnosis makes sense to me! It also brings up a question about how often they are writing power data to the flash, and what the chip manufacturer’s specified write lifetime is on that flash?

Both of the LZW36’s that I have installed so far are showing the occasional dip. Is it annoying me so much that I want to drop the fans and send both canopy modules out? Not yet…

Yeah, I agree that will be a tough one to find the interest to do since we use the fan lights so infrequently but it is noticeable when we do so maybe. I wish it could be updated OTA like the switch module.

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So we will have to send back to you the faulty canopy module? What will happend to people that live outside USA?

Great news. I waited a long time for someone to create this type of switch, I can wait a little longer for this fix.

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Awesome - glad they were able to figure out the root cause! Thanks for the update

I’ve still got a LZW36 destined for a fan that I need to rent a 16’ ladder to reach … how do we get on the list for a swap out module or firmware upgrade once available? I’d rather not risk needing to rent the ladder a second time (the ladder rental costs more the switch, not to mention the logistics of getting it to/from my house).

Will future purchases have the update installed on them? Or, will you only do the update on the ones installed showing the symptoms? The reason I ask is, because I have two fans I still need to buy the switches for. If the new switches and modules had the updated firmware, I could swap out the two fans with the problem with the new switches and modules and avoid not being able to use the lights. I could then send in the old modules and wait for their return before installing the other 2.

Yup - I am in the same boat. Will be watching for updates. I do want to say, Thank you Inovelli for being open and transparent about the issues you seeing and what you are doing to fix them! Better to get it solved upfront instead of having to rent a ladder or scaffolding again to pull down the canopy module.


I completely understand, single core MCU trying to do multiple operations, and the scheduler has to disable interrupts to complete the flash block re-write request (critical operation that can’t be interrupted).

Next question you should be asking; what is the durability on the flash writes? How frequently does it write? What happens when writing to the flash module fails? Embedded engineers should know that constant block writes will eventually lead to module failures. Hopefully they have some module wear leveling in place to at least extend the life of the module.

They should be writing the values to SRAM or something that is made to survive constant writing to them.

Edit: Is there a way I can configure the canopy module to disable flash writes? Personally, I probably don’t use this feature (if this is related to power monitoring?).

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@JasonL_Inovelli – can you answer this? I’ll also shoot you a PM asking.

Yeah, this is something we regret not doing for sure. I think we’ll be working on this for the next round.

Yeah, that’s unfortunately the plan. As for the people outside the USA, I guess we’ll be paying extra for shipping to/from you lol! We’ll take care of you – this is our fault :slight_smile:

I appreciate it! It’s been a fun ride and we’re glad we’re ironing out the bugs now and appreciate everyone’s patience with this. We thought we caught everything and were excited to bring this to market, so these minor setbacks are frustrating.

You’re welcome!

Once we receive the new units, we will make an announcement here. Good news is that they are producing them now. Just shoot myself and @Courtney_Inovelli a PM and we’ll get you on the list :slight_smile:

So there are about 500 or so left out in the wild on Amazon/HQ to purchase that do not have this firmware on it. Right now, they are producing new switches in the next couple weeks (they want to make sure this flickering is completely resolved – initial testing shows it has been resolved, but they want to give it time). The new units will have the updated firmware on it, but I would give it a month or so to be certain.

We will likely be announcing it via the community when new stock comes in so if you want to shoot @Courtney_Inovelli and myself a message to confirm getting one with new firmware, that’s totally fine!

No worries, happy to be. It’s easier to get in front of a problem then have to clean up a mess afterwards by hiding it lol.

I’ll ask @JasonL_Inovelli! Great questions.


For those of us with the flicker and old switch firmware, will there be an option to swap both the switch and the canopy module? I have 2 units and have been debating on going through the firmware update process (would have to purchase hardware) or living with the original firmware and related issues (I’ve worked around the firmware issues based on recommendations in another discussion). First inovelli products, and love the switches overall.

Yeah totally, we can do that!


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I installed 3 of these switches last week and encountered the same issue with the lights randomly blinking on and off… this usually occurred within the first hour of the light being turned on… I’m glad that the cause of the problem has been found and that it is not due to any problems of my physical installation of the units…
Seeing that the issue was related to the unit reading power levels, I decided to try a quick experiment… I set parameters 28,29 and 30 all to 0… this disabled the power and energy reports as well as the timer for when the reports were sent.
I’m not sure if it is just a coincidence or not, but after doing this I have left the lights on for several hours and have not had a reoccurrence of the flickering … Perhaps someone else can try this and see if it fixes the issue for them as well?
I’m no longer able to see any updated power reports after doing this, but fixing the flickering takes priority…
If this is confirmed to help the issue, perhaps a firmware for the switch rather can canopy can be an alternative? I definitely am not looking forward to having to remove 3 modules, shipping and reinstalling … But if this method works for people who do not need or care about the power reporting, then perhaps this will save the trouble and the who choose not to send the units back can be compensated with a discount on other switches?