This is a mighty fascinating video! Reverse engineering is really where I'm at, and I love learning how others go about it. I learnt something new again! Thanks for that.
great stuff, but still didn't understand how the auto addressing works, say if an LED module dies mid string does the address of the next working one change i.e. does the address get shifted down. Not clear how exactly the address gets set, what happens if there is a failure whilst powered and after power off & on again.
If a module dies in the middle of a string taking out its power supply, it no longer exists on the bus. It is no longer able to do anything to the data when that relay is in its default no-power condition of Normally Closed. Assuming there's no power to the microcontroller, there should also not be any lighting happening as it would not have any way of listening to packets or driving the LED drivers. You are correct that, if a module dies in a way that's not just the power supply circuitry or while it's powered on, there will be anomalies. If a module dies in a way where it behaves abnormally but with the STC microcontroller still working just fine, it may take up an address and otherwise be a dud not responding. It may get stuck on a certain colour if the microcontroller fails in a very particular way. Regarding the addressing: The circuitry inside each of the lights is capable of essentially deafening everyone in the string that comes after it by not repeating the data. So the string gets enumerated one by one, where each of the lights gets told "pick an address, and tell the next one to start at 0x06" (or whichever address the previous one was). The next light is always told what address the previous light took, and they are programmed to sequentially take an address that's n+1, i.e. address 0+1 for light nr1, address 1+1 for light nr2, address 2+1 for light nr3. Since each light is capable of deafening the outputs, the light that's currently being told to pick its address (by the previous one) always prevents any lights that come after it in the series from hearing any data until it has picked its address, and has started sending out modified data containing its own address and the command to the next light to count one up from there. I assume the length of the entire sequence is because the controller is blind to this. It doesn't know when it has stopped enumerating lights. It's a one way street. So the controller just runs the auto addressing (sequential enumerating) programme for as long as the developers have programmed it to, which is likely in some way inclusive of some kind of worst case timing or dropout time added. It just runs the sequential enumeration until it logically makes sense that all lights that *can* do so, have picked an address. At the end of this sequential enumerating sequence, the controller tells the string of lights to come out of this mode where they pick an address on their turn, and that probably switches the circuitry into passthrough mode using the logic IC's. Since every light now knows their own address (self-assigned), they will respond only to data that's destined for them. From there on out, it's free real estate. The lights run on their own from there on out, and it's up to you writing the lighting programme (scheduled changes etc) to know how many lights are in the series for you to address.
Fascinating. I don't understand a large proportion of what you are doing but I find that I learn so much from watching your videos. Your analysis and explanations are top class. Thank you for sharing.
Could it be, that the protocol being used is DMX TTL 1024? have you tested how much you can connect after eachother? I would not be surprised if it was just that protocol. I do like what you show in this video, it really breaks down what can be done to use something, that has a proprietary controller in place.
Nice find. Quite a few years back I picked up a set of DMX floodlights that had been removed from the London Eye when they revamped it. Even older LEDs than these, with a row of lenses above the LEDs in each unit. Again, nicely made units for daisy chaining, and still going strong.
Hi! Is it possible to measure some standby current for some of these lights and controller? I'm trying to develop a PoE lighting system with either RS485 or CAN-bus over CAT5-6 cable. Standby power usage is one of the most important factors for me, this is quite similar. Thanks!
Very interesting, love just how solid the pixels are. They could take a bit of abuse before anything leaked or broke. You can see why they would have been very expensive.
6 years of schooling for electronics and electronic engineering and i still dont understand how developers/ engineers compile all of the different components and circuitry in their heads creating a boardset for things.. while maintaining proper voltage and current levels, mitigating noise and feedback/ emi and incorporating it all in the matrix to complete the task at hand. I got a job as an intern at bose sound and audio engineering which made me just forget about electronics and focus on high voltage. They have a team of engineers, 4 at the location i was at, who all are assigned a task in the development of something. While i was there they were on the topic of real time spacial audio noise cancellation with audio replication of supersonic and subsonic frequencies. this was back in 2007.. and was technology that was not and is not even available yet. But is probably for the military. Anywho these guys each had a dining room meeting size table in their offices each piled with paperwork, doodles, equations, designs everything. Multiple whiteboards with scribbles of ideas and whatnot and also a bunch of broken crap where they got pissed something didnt work and relieved their anger. All of em were bald and obviously stressed out. None had any home life and would sleep at the office much of the time. But they told me that theyd get a timeline with the task at hand and get around 10 of these at a time varying from the impossible to simple phase filters and passive audio builds. But as soon as they would finally complete one theyd immediately have to wipe their minds and get handed a new task. 24/7.. a life of being frustrated trying to figure out why a simple networking circuit keeps blowing a fett and making one change in turn makes the entire compilation completely change components.. then finishing with that sense of accomplishment just to have to do it all over again until you have an aneurysm or heart attack or stroke.. which out of the 4 guys there 3 have already had 1 of the 3 but were still there.. meanwhile the breakthrough tech they develop goes on to make the company billions while they are paid their salaries with no benefit because its all proprietary and they own your genius.. lol. Fuck that.. i set up warehouses and factories now..
And yes, at some point many of the things you do are just that way because "we just do it that way". Like picking pullup resistor values; we don't often go out and calculate the exact ideal value. We just kinda slap something on there which we kinda know to work and... evaluate in hardware whether it works or not.
PCBWay 3D Printing and Fabrication: www.pcbway.com/rapid-prototyping/
Support the Channel with Patreon: www.patreon.com/sdgelectronics
Could be someone out there willing to pay a lot for a working controller if they have these lights installed.
That's a lucky find on ebay.
I'll have to step up my search game.
This is a mighty fascinating video! Reverse engineering is really where I'm at, and I love learning how others go about it. I learnt something new again! Thanks for that.
Amazing reverse engineering and a nice find. It looks like quality gear - I hope your neighbours appreciate the rave in the garden!
great stuff, but still didn't understand how the auto addressing works, say if an LED module dies mid string does the address of the next working one change i.e. does the address get shifted down. Not clear how exactly the address gets set, what happens if there is a failure whilst powered and after power off & on again.
If a module dies in the middle of a string taking out its power supply, it no longer exists on the bus. It is no longer able to do anything to the data when that relay is in its default no-power condition of Normally Closed.
Assuming there's no power to the microcontroller, there should also not be any lighting happening as it would not have any way of listening to packets or driving the LED drivers.
You are correct that, if a module dies in a way that's not just the power supply circuitry or while it's powered on, there will be anomalies. If a module dies in a way where it behaves abnormally but with the STC microcontroller still working just fine, it may take up an address and otherwise be a dud not responding. It may get stuck on a certain colour if the microcontroller fails in a very particular way.
Regarding the addressing: The circuitry inside each of the lights is capable of essentially deafening everyone in the string that comes after it by not repeating the data. So the string gets enumerated one by one, where each of the lights gets told "pick an address, and tell the next one to start at 0x06" (or whichever address the previous one was). The next light is always told what address the previous light took, and they are programmed to sequentially take an address that's n+1,
i.e. address 0+1 for light nr1, address 1+1 for light nr2, address 2+1 for light nr3.
Since each light is capable of deafening the outputs, the light that's currently being told to pick its address (by the previous one) always prevents any lights that come after it in the series from hearing any data until it has picked its address, and has started sending out modified data containing its own address and the command to the next light to count one up from there.
I assume the length of the entire sequence is because the controller is blind to this. It doesn't know when it has stopped enumerating lights. It's a one way street. So the controller just runs the auto addressing (sequential enumerating) programme for as long as the developers have programmed it to, which is likely in some way inclusive of some kind of worst case timing or dropout time added. It just runs the sequential enumeration until it logically makes sense that all lights that *can* do so, have picked an address.
At the end of this sequential enumerating sequence, the controller tells the string of lights to come out of this mode where they pick an address on their turn, and that probably switches the circuitry into passthrough mode using the logic IC's. Since every light now knows their own address (self-assigned), they will respond only to data that's destined for them.
From there on out, it's free real estate. The lights run on their own from there on out, and it's up to you writing the lighting programme (scheduled changes etc) to know how many lights are in the series for you to address.
Great video! Thank you.
looking good. I think I'll be able to see the reflection in the clouds from here. 🙂
Fascinating. I don't understand a large proportion of what you are doing but I find that I learn so much from watching your videos. Your analysis and explanations are top class. Thank you for sharing.
Could it be, that the protocol being used is DMX TTL 1024?
have you tested how much you can connect after eachother?
I would not be surprised if it was just that protocol. I do like what you show in this video, it really breaks down what can be done to use something, that has a proprietary controller in place.
Nice find. Quite a few years back I picked up a set of DMX floodlights that had been removed from the London Eye when they revamped it. Even older LEDs than these, with a row of lenses above the LEDs in each unit. Again, nicely made units for daisy chaining, and still going strong.
Hi! Is it possible to measure some standby current for some of these lights and controller? I'm trying to develop a PoE lighting system with either RS485 or CAN-bus over CAT5-6 cable. Standby power usage is one of the most important factors for me, this is quite similar. Thanks!
Standby when all lights are off, no data being sent?
@@AnnaVannieuwenhuyse yes, that's the most important metric for power usage in my opinion!
Great video!! Do you know the part number of those board-to-board connectors in the LED board? Best regards
Very interesting, love just how solid the pixels are. They could take a bit of abuse before anything leaked or broke. You can see why they would have been very expensive.
Wow. Complex.
awesome! Waiting for part 2 😄
amazing!
6 years of schooling for electronics and electronic engineering and i still dont understand how developers/ engineers compile all of the different components and circuitry in their heads creating a boardset for things.. while maintaining proper voltage and current levels, mitigating noise and feedback/ emi and incorporating it all in the matrix to complete the task at hand. I got a job as an intern at bose sound and audio engineering which made me just forget about electronics and focus on high voltage. They have a team of engineers, 4 at the location i was at, who all are assigned a task in the development of something. While i was there they were on the topic of real time spacial audio noise cancellation with audio replication of supersonic and subsonic frequencies. this was back in 2007.. and was technology that was not and is not even available yet. But is probably for the military. Anywho these guys each had a dining room meeting size table in their offices each piled with paperwork, doodles, equations, designs everything. Multiple whiteboards with scribbles of ideas and whatnot and also a bunch of broken crap where they got pissed something didnt work and relieved their anger. All of em were bald and obviously stressed out. None had any home life and would sleep at the office much of the time. But they told me that theyd get a timeline with the task at hand and get around 10 of these at a time varying from the impossible to simple phase filters and passive audio builds. But as soon as they would finally complete one theyd immediately have to wipe their minds and get handed a new task. 24/7.. a life of being frustrated trying to figure out why a simple networking circuit keeps blowing a fett and making one change in turn makes the entire compilation completely change components.. then finishing with that sense of accomplishment just to have to do it all over again until you have an aneurysm or heart attack or stroke.. which out of the 4 guys there 3 have already had 1 of the 3 but were still there.. meanwhile the breakthrough tech they develop goes on to make the company billions while they are paid their salaries with no benefit because its all proprietary and they own your genius.. lol. Fuck that.. i set up warehouses and factories now..
It's like learning the piano. You take lessons to learn the basics, then you have to practice and practice!
And yes, at some point many of the things you do are just that way because "we just do it that way". Like picking pullup resistor values; we don't often go out and calculate the exact ideal value. We just kinda slap something on there which we kinda know to work and... evaluate in hardware whether it works or not.
hey SDG, when will your website be revamped?