The comments/feedback is crazy!! Thank you all for your awesome ideas, suggestions, tips, tricks and whatnot. Really awesome to hear so many advices, opinions. I think part 2 of this project will be a "community" video in which I will partly test your ideas. Will be lots of fun. But it will certainly take a while until I get to that. So stay tuned ;-)

I appreciate more the "I failed" videos than the "here how do to X perfectly". This is the best way to learn something and understand a project.

I found where you have the problem!!!! I also double checked with a electronics technician that has 50+ years in component level troubleshooting and high frequency circuit design who just happens to be my father that my suspicions where correct. He was able to give a solution and explain why it was happening along with why you were getting that specific frequency. Your driver circuit for the LED needs a second filter on the other side of the coil (U6) but before the diode (D3). In the current configuration, with the PWM being fed into there, you are pumping a RLC circuit in a single direction that has no where to release its energy other than ground and the power monitoring pin of the micro-controller (pin PA6 of part U3). Since it is going though a series of diodes, it is reflecting off of them and this is causing a doubling of the frequency. If you run a RLC calculation f = 1 / [2π × √(L × C)], you get 7.341 kHz for with the ideal component values and 14.682 kHz for the doubled, which is within 95% of the ideal component values, so accounting for the variance in the parts and the sub-harmonics we are seeing on the oscilloscope, this is pretty good proof that the hypothesis is correct. To test it further, removing a single unit for testing would be advisable and then replacing filter capacitor C10 with a different value or adding one in parallel to change the value and then checking with an oscilloscope might be a possible way to check for it. It is also possible that the oscillating circuit is internal to the LED driver IC, so adding this cap may do nothing, but adding the filter at the location that I specify as the solution is going to still work as that is the correct filter location in the circuit. You are going to need to put rejection filters between U6 and D3 that only pass DC and the fundamental frequency for your PWM signal. You could also get away with a low pass filter if the fundamental frequency for the PWM is low enough. I would suggest changing the PWM frequency to a lower value so that you can just use the low pass filter as high frequency noise is easiest to filter out. The datasheet for the micro-controller shows how to do this. As long as the resulting frequency is at least 10% below 7 kHz it should get rid of the noise. Assuming you are on the default settings for it, you should be well below that, but double check. Now as to the why on why this was causing so many problems with the micro-controller. The default clock speed of the micro controller might be set to 16 kHz (+/- 3% over voltage range and +/- 2% over temp. range) by default, so, if you have a signal on the other end of the PWM output pin that is close to that and really noisy while being unstable, like you have, and that pin isn't optically isolated (which this micro-controller doesn't have optical isolation on its I/O pins and problems like this are why you want optically isolated I/O pins) the interference can be feeding back through the circuit and causing problems with the PWM circuit. 97% of 16 kHz is 15.52 kHz, which is close enough for some signal coupling, so it can feed back into the circuit and cause the clock for the PWM to start having errors that the processor will have to correct, which will cause all sorts of strange behavior. I would change the internal clock that the PWM is using to the 20 kHz mode that the micro-controller has the option of using to just completely take it out of using a similar frequency. Make sure that the fundamental frequency that gets produced by the PWM still stays below the 7 kHz range using the equations given in the datasheet for how resolution and clock selection and clock type result in the output PWM signal's fundamental frequency. Just putting the filter in will probably fix most of the noise, but lowest noise possible is the best thing to do when dealing with micro-controllers. I would suggest in future only using micro-controllers with optically isolated outputs and always make sure that if you have a cap and coil in series in an oscillating circuit with diodes that you have a filter for both directions that the coil can discharge unless you are trying to make it oscillate or build a higher voltage.

6:50 you can use a diffuser cover and drill tiny (1mm diameter should suffice) holes right in front of the IR sensor.

The design of the data lines won't work as indended as described at 5:12, there should be one diode for each OUT pad, not one for both. In your current design, every other board is commoned together via the OUT-Line of the board in between: Board A In2↔Board B OUT1/OUT2 ↔Board C IN1/IN2 ↔Board D OUT1/OUT2↔Board E IN1/IN2... Most likely that's why all the boards were lit in most of your initial trouble shooting. The boards at the top of the stair (which later you found missbehaving) pulled all the other inputs low, until you introduced smaller pull-ups until the voltage drop was enougth to be registered as low.

Perhaps use a white Pcb next time? Might blend in a bit more. Canny help debug unfortunately.

If you redesign the boards, it might be easier to use connectors to slide them together, soldering them all together will have to many failure points and you cant take it apart to diag and repair.

I did this using an addressable strip, arduino and 2 pir sensors for top and bottom, it's been working great for around 7 years now

To be honest this was one of the most eye-opening of your videos to me. Seeing such a theoretically simple and trivial project experience issues due to noise and other things.

It's legit more enjoyable to watch the fail videos than the success videos. The fails are where you REALLY learn something new.

@greatscottlab LED Lighting Electronics Engineer here. I reviewed your project files and a few things: 1) put 0.1uF and 10uF cap on the input and output of your LED switcher. You actually need a high freq cap and lower freq cap to cover the freq range for input and output ripple 2) I like the 4-layer idea, but do 2 internal layers of ground, and only route on top and bottom. Also, make sure to sink a ground via right next to every signal line via (this will help the signal keep good ground reference and force the inductive coupling on the internal layers to follow a set path. Try to reduce the number of vias per net as much as possible (don't want added inductance) 3) Make sure to look at the recommended switcher layouts and make your switching nets small, and DO NOT let them go onto other layers (don't want to have inductive coupling between layers). Also, try and get ground between traces so you don't get cross talk. At the lengths of your PCBs, I'd expect you could get Volts worth of cross talk, even at sub 100MHz freq. 4) I'd add a common mode choke to the input of every PCB and a Pi-Filter too. It may be overkill, but for a few extra bucks you grantee each board isn't getting noise on the input. Make sure to route this all on the same layer as the connection between boards (so top layer for you). The shear length of the boards all ganged together is working against you and stray fields from surrounding power lines and appliances/electronics could get onto the boards and cause some weird behavior. Better to go all out and find you you don't need it then to find out you do need it haha. I highly recommend "philslab" on youtube as has some great videos giving best practices. The whole FEDEVEL group is very helpful for PCB design for EMI / EMC. Wish you the best of luck man! I love your videos and love the idea ;) Keep it up man!

Frugal Engineer : This can be done with two proximity sensors, the 1st at the beginning of the staircase and the 2nd at the end. Keep the entire LED strip on until you pass the ladder. Use reliable MCU and LED drivers. As per my understanding, you don't want to manually turn on/off the house lights, and you don't want big bulbs to be lit

i don't know why your impression of your girlfriend was so funny to me

Nice to have pictures of yourself everywhere on the walls. 😂

When I made some under cabinet led tape lights integrate with doors and mains power about five years ago, I had a similar story. A "weekend project" spiraled into about 8 work days of effort and required a one year break for "finishing touches". I could not be happier with the results, even thought it needs another minor touch up. Your project is so much more ambitious and I cant wait to see how it turns out!

I appreciate you sharing this even though it didn’t go to plan. Being able to see how other people investigate and solve faults is incredibly useful 😊

Maybe the IR distace sensors are interfering with each other. Try to place a narrow tube infront of the sensor to narrow it's field of view.

it's actually really nice that you share the files and a list of the used components for the projects you do, kodus:)

I feel your pain, my friend… we all have those frustrating project experiences. Thank you, for sharing yours. I’ll look at the files and think about this and send any thoughts later. Great video, as always! 👍😊👍

I love that you show what didn't work. I'm still at the beginning and my first thought would be to illuminate the whole staircase dimly with a few presence detectors (including beginning & end) or use buttons for simplicity and use a timer to turn it off after a suitable amount of time. Illuminating each few steps individually seems like an anti-feature feature because we literally lookahead to plan our steps in advance.

You could use the WS2811 IC, it's the one that is in the neopixel, just replace the RGB LEDs with white LEDs, like that you can control 3 white LEDs with one data line. That way removes the need to have a constant-current source (or sink) to drive the LEDs with a PWM (or any switching power regulation), and then also removes the high frequency noise that could be induced in the circuit.

Modifying things as soon as we get them is how we operate.

I was going to make animated lights on my staircase but decided a simple "all on", when a person is detected, was safer. I used a multivibrator circuit to turn on the lights for 30 seconds, and re-trigger whenever motion is detected. Fancy lighting effects look cool, but are distracting and dangerous IMHO. I love your method for mounting the LEDs. I chose to do the massive wiring to each LED approach, lol.

Great project! Thanks for honestly sharing that not everything worked as expected!! Super helpful for the listeners to learn as well!

Great attempt for a sleek solution, good luck for v2 when you'll get back to the project 🤞🏻

You have noise on the Input Pin (PA7) Add a 100nF capacitor between PA7 and GND. Place the capacitor close to the ATtiny402. When using long wires, in your case long traces, you made a Antenna. All input pins should have Capacitors on them, but the higher the capacitance, the lower the switching speed, so you'll have a lower transmission rate

This reminds me of a project I built back when I first started tinkering with electronics: A motion sensor based light controller with a PIR motion sensor. It worked beautifully most of the time, but whenever someone would flip on the light in the next room over, it would trigger the motion sensor resulting in the lights coming on in the middle of the night. I suspect I had similar issues with the input voltage fluctuating too much and confusing the sensor. Thank you for the great video, keep up the good work and don't give up!

What a great project. Well thought out and implemented (almost). I look forward to the next episode. As always, keep up the good work.

Can you maybe do a video about "Choosing the right microcontroller for your project"? Or generally explain how you search for a suitable microcontroller

Oh man I LOVE the "we just got this staircase, you will not damage it in any way". Any tech man needs a woman like this to keep things sane. My girl does the same. You girl is a keeper :)

Had very similar idea back in 2021 while building my stairs. Wanted to do all just using analog discrete parts. Never actually got to it. Good luck with your project and thanks a lot for the kick I probably needed to get back to this project.

Great project! And nice to see you working on a solution! I hope you will get it working!

Is the prox sensor seeing the stair itself and activating? I noticed in the video it appeared that your knee was activating the stair above.

Great that you’re also sharing failures! Do you really think the noise on the VCC is causing this and not a coding issue?

One of the cleanest projects of yours.craftsmenship is great.👍👍

I love it, amazing project. No matter if it was a fail. Thank you for show us that sometimes something could be wrong. I enjoyed a lot with the concept, process and the creation. My wife also sit next to me often and say to me: Do it but don't broke it 😅 I'm looking forward for the V2 and probably you should consider to sell it! Could you consider to use a white cover for the Ledstrips and a small transparent section for the sensors. Great job!! 👍

My solution: Up and down is one HLK-LD2410, both connected to ESP8266. The bottom one has one pin connected to LED strip with WS2812 LEDs on the whole path of the stairs. Once motion is detected near the bottom one, the LEDs will light up from bottom to top. Once the motion is detected on the top one, it sends the signal to the bottom one and the stairs will light from top to bottom in "usual" walking pace. Works great, keeps the light on for next 5 seconds, to allow kids to, for example, find the entrance to bathroom, or to the next staircase, then the lights "go out" in the same way the came in. Works great, the whole solution costed less than $30, if I do not include the aluminum LED channels - those were the most expensive part of the project in the end :) And as this is radar, I have no problem with transparency of the plastic ;)

An addressable led strip with a ESP32 with WLED and two IR sensors (one on top of the staircase and one at the bottom) could do the trick relatively easy (even change the effect/brightness at certain times of day). Maybe even coupled with home assistent to intergrade in the smart home.

I did a similar project with a lightstrip and two movement sensors, one at the top and one at the bottom. This way you can program the lightstrip to light up gradually starting at the sensor which was activated. Looks pretty smooth. And quite easy to implement!

Thank you for sharing this and your frustrations. I recently pushed myself really hard on a very large project and kept running into roadblocks over and over again that were very difficult like these and it was incredibly difficult to keep pushing myself forward but I finally did and I finally worked through them all and finally figured it all out. Hang in there you got this you will eventually figure it out it's probably just a silly piece of code that you didn't realize because you were going so fast

Scott imitating his wife was gold.

You simply should enable only 1 distance sensor at a time, not all at once. Distance sensors are interfering with each other when they are simultaneously firing . Also most probably the distance sensors are the ones that create the noise.

This is a pretty nice project. Happy you made it available to everyone!

That is such an excellent project! I see where you were headed with it, (and kudos for working as a carpenter for a bit- THAT can be quite frustrating if it's not something you do all the time!) I learned some things, and JLCPCB pricing info... I can't wait to get home so I can work on some original design boards to try them out! Don't feel bad, that try, fail, retry, walk away loop happens to all of us!

Wouldn't the ground and/or VCC planes act as a rather large antenna like this?

Love the part where he tries his best to sound like his girlfriend.

Love the project! Me and my brother has been thinking about a similar solution for his stairs! Not sure I can help too much but really nice work! 🎉

Finally the content im expecting from this channel. Great idea with good approach about ho to solve it. Not matter failed or not.

Was this the first appearance of the angry girlfriend? 😂

100% need the next iteration of these and update video! Been wanting to something like this for a long time. I did a much "older" variant using lasers and LDRs on each step as well as some ultrasonic stuff -- this is a much nicer solution once the bugs get ironed out

It's immensely relieving for me to see that I'm not the only one who doesn't get it right immediately. Thank you GreatScott! And: would love to hear how you'll fix this (and I know you will!)

Your girlfriend is very strict 💀

Why just use Fiber Optics instead, just distribute the optics on each step.

Great project. I love the fact that you take us all through the design, build and problem solving and not just "look I build X and it's working". I can't wait to see how V2 gonna be.

Loved the video! That is a really interesting project and an original idea on how to tackle this

This looks like an excellent project. Well done for taking a break. When you pick it up again I bet that you find a solution. Good video as allways.

I love your idea and execution... Was thinking about a project like this before but sadly I'm not smart enough to get it happening like you... Respect I appreciate each and every of your videos for the knowledgeable content... Weiter so...

It took me three weeks four different tries with the programing (worse than you in that area). Finally went to a friend about the code he showed me that using a state machine was the best case and it mostly works. The issues on the board like noise and signal integrity were mostly the board layout and lack of proper filtering. I have built this in two different places, and for the most part they are still working. Had an LED go out on one about a year back. Mine are made to react to the step before being on or off state. Also had to angle the motion sensor up at a thirty five degree angle to keep the cats from playing with the lights. Peace

Great project, you will make an amazing second version down the road. In the meantime taking a break sounds like a good idea it can get pretty frustrating at times. Great work as always!

Great ingenuity! Awesome video, as usual.

Thank you for the video, i really like it when you show that failure is Part of the process

Nice project! Thank you for sharing your experiences!

I LOVE THIS PROJECT!!! I know you feel frustrated by it but you definitely when through all the troubles and troubleshooting problems someone would have gone through when developing a small project and i love it!!!

I came accross this brilliant video a couple of weeks ago and absolutely loved it, including the issues and how you try to deal with them. All of a sudden, I don't feel alone anymore :). I found the idea very good, so I had to try it and sourced a few components and knoked up a few boards on the micro cnc and wired everything > I modified ever so slightly the schematic and the code to address some logic issue with the pin In and Out. On one board everything works, but as soon as you connect several boards they start firing up randomly. Like you I spent a bit of time trying to figure out what happened. My conclusion was that it was nothing to do with the noise on the in/out line. In fact the issue is the variance in the response from the VCNL4200 sensor from one unit to the next and also within the same unit!. So I finally got it to work by measuring a "reference threshold" in the setup of the code (so I might have different value for each sensor) and also by taking the average of 11 samples for each reading of the proxy sensor. That completely fixed my issue! (I think ;) ) If you are interrested in the code or schematic I can of course share it. Thanks again for your great work!

VL53L1x is a Lidar sensor from ST. it worked well and came cheap at cost. Program the sensor to turn LEDs "ON" position for the next two LEDs. I learned many things from you.

Great idea, seems like most electronics projects i take on, always hidden problems, would love to play with your design, singularly they work well.

This is great, Scott! As other comments mentioned, I would consider using addressable led strips, but also taking advantage of the different colors you can turn on. At night, the blue light is the one you should avoid, so you might turn on the leds on yellow color.

I’ve learnt 1000 times more from projects that don’t work as expected than ones that do. I love the concept it looks fantastic. 👍🏻

Great idea, I hope you get it working soon.

Thanks for posting this! I am looking to do some diy stair lighting also and I learned a lot

Its nice to see pros like you failing sometimes. I curently have a similar project wich makes trouble over and over again.

Really nice project! I gotta be honest, kinda felt good to see others having unexpected noise problems ruining their projects ^^' You definitely have to make a video about the solution (whenever you get back to this). Can't imagine to work involved in make these videos, but it's really nice to see the development and debugging process done by others. Great video and good job!💪

Fun project and especially when you get it resolved. It reminds me of a stair case in the Science Museum of Minnesota. Each step triggers a tone and as you go up, the tones trigger and get higher with each. Reverse when going down. Quite fun.

WS2812b wled with custom PCB is what you need, has staircase mode now also.

I love this kind of video! I recomend you a lot of times in my classroom :P

I love the I tried it this way and it failed, and tried it another way and it failed over and over relentlessly. the break is going to help you piece together all those moments and you're probably going to discover the cause: whether it's some frequency, heavy pulldown, floating grounds etc. Kudos "Great Scott" for the endeavours.

I think you should use higher voltage such as 12 volt with an optocoupler as low voltage is easily get affected by noise, and also use a 555 timer ic for PWM and time delay which can be triggered by a normal IR sensor. No need for a attiny. But all and all It was a very nice video for me because it gave me a chance to think.

Im really looking forward to see finished product

I had a project like this but in the end i used a commom led strip, cut it in the minor lenght (3 LEDS) per step, fixed it in the handrail facing downward and used a PIR sensor to turn on the hole stair case. Also its integrated in Homeassistant so it can serve as indirect light for the living room. It's not that fancy indeed, but helps a lot

brilliant idea..nice execution as well

A bunch of sensors can mess with each other. I went with radar (Doppler GHz) at top and bottom, they are far enough to not see each other. Then you can turn on all the LEDs in sequence (away from motion) and control them all from nice microcontroller. Giving you tad more time to move past them. Then shut them down again in sequence. And those radar sensors are so awesome!! Oh, addressable LED’s could share power and data. And I agree, we love learning along side you. My projects go the same way! ;)

This is a cool concept, we were thinking about upgrading the lights in our staircase soon, maybe something similar would work nicely.

Hey, i made it once for a project expo when I was a kid, and the thing is it works perfectly and as i remember it consists of components like ir sensor (photodiode n ir led), lm358 ic, ne555 ic, and transistor as a switch.

Awesome project (-idea). I hope you get it working soon! 👍

great project I have never heard about, but I would never get idea to do such project since I never had issue to walk on stairs during total dark.

You could use your clear covers and add defusion to them and leave the area in front of the sensor clear so they still work as intended. Projects like this rearly work right off so it's nice to see a realistic expectation here where it doesn't work right the first time. I like your solution for mounting the light strips and not attaching to the staircase itself you even got a good colour match, well done.

Thanks for sharing the failures and not only the successes. It's very educational and shows how making projects normally go. It's never pure success. One though I had during the video; I guess you can still use a diffused LED cover as long as you cut or drill "windows" where the sensors are.

You are indeed making me feel my age. When I was young, from birth to age 12, we lived on what was called the "home place' an old house built by grandfather in 1910. While REA came through and put a high line pole in our yard, nobody bothered to run a wire to the house or for that matter wire the house for power. So it was, when we went to bed in the 2 rooms that were "upstairs" we climbed the steps which were painted white but have a black mat on each step so there was pretty much no light other then that small flickering lamp that mom had lite in the kitchen below, that being a kerosene lamp. We would go up-stairs using all 4 limbs, hands on the step above and feet on those below till we reached the top which had no landing to speak of, just turn and you were in the first upstairs room, there was a drop down door that we had to lower once we were up there to keep the heat in for the downstairs, In the second room were two beds, one large for my sisters, and one small for me. That room had a lover that could be opened to allow heat from the coal space heater in the living room where my folks slept in winter to stay warm. The upstairs had no finish on the walls or ceiling, in the winter the shingle nails on the roof would have heavy frost on them, and when we woke up it was common to see your breath in the morning light that came from the one window that faced the East. It was a good life though, we all grew up to be successful, and all of us were very creative, you see you had to be because there were no televisions, phones just a battery pack radio that was high enough that we could not reach it to turn it on without a stool to stand on (batteries were expensive in the 50's)

Thanks for sharing your problems so others don't "fall" into the them. Engineering is all about iterating so no shame in prototyping. Can I suggest having LIN bus or another com line among all the sections so not only will they light up where you step but where you are going to step. The LIN bus would also help you debug so you only have to talk the primary chip to debug the entire strip.

looks like my advice for micro-controller worked. Happy to see that.

I have that same tiny hotplate. I cut a couple of blocks out of wood the same height as the hotplate to help support larger boards. It's a lot safer to use!

i loved this project soo much, this is can turn into a wonderful product. please think into that.

Please share more " I failed" videos. These help us so so much. Thank you.

I love this project in particular. One thing that I could try if I was you is to try to optically isolate the sensors in a sort of rectangular tube, because it seems to me that the sensors are receiving bouncing IR from each one as you move into the stairs. Happy debugging!

You can use the diffused covers and drill small holes at the sensor places :)

I love the idea and design. As I am a software guy I sadly lack the tools to tackle such a project and my last soldering was 15 years ago at university. For aesthetic I would recommend you testing again with the diffusor and some drilled sensor holes, maybe even with a clear plug as dust cover.

Cool Project! Two ideas i got: Maybe the sensors see each others signals and get confused? and you could use the aluminum profile as a ground, by having exposed ground pads along the edges of the pcb

Thank you Scott for sharing this video

On a similar project that I worked on; we needed to send a signal across interconnected PCBs without limiting the number of boards that could be connected. We used a buffer IC to refresh the signal from board to board so no significant voltage would be lost if the user wanted to connect several boards together.

you can use wled,they have a mode that you can attatch ws2812 addressable led and will light up one by one with ultrasonic distance sensor,designed exactly for this use