Gunners TekZone Posted January 17, 2025 Author Posted January 17, 2025 12 minutes ago, Toastie said: the Star Trek folks teleported without any device present on the target site Theoretically, they had to scan the area?. But I would probably prefer the Jumper method (required a viewpoint of destination??). Cross over whole at a joined time/space local as opposed to getting "killed" (however you look at it, that's what seems to happen) and "rebuilt" after transmission. The spirit is immortal, this body... not so much, and I would like to keep it together for as long as possible However the geeks and nerds debate it... I personally think a jet might have to be involved :D But for now, I will follow along in these fun technical LEGO discussions! Quote
Toastie Posted January 17, 2025 Posted January 17, 2025 48 minutes ago, Gunners TekZone said: But for now, I will follow along in these fun technical LEGO discussions! Yeah, you are right. So we settle on 2A max. for the Interface B 12V AC juicer transformer? Best, Thorsten Quote
Gunners TekZone Posted January 18, 2025 Author Posted January 18, 2025 (edited) Wow... I can see if I m going to get back into electronics, I need to seriously upgrade my desoldering toolset. Those cheapy spring pump things are bad, but I have nothing else, not even wick. Thankfully I need not make use of those pads anymore. BUT... I was clearly in a zone (twilight zone?)... I didn't realise that if I expect to put this USB-TTL adapter in there, I need to relocate that capacitor, which is so nicely gooped in :/ Edited March 16 by Gunners TekZone Quote
Gunners TekZone Posted January 18, 2025 Author Posted January 18, 2025 (edited) Whew... desoldering (and resoldering) with a dual sided ground plane is surely fun for the whole family! NOT! Thankfully, I had a new capacitor of same value (higher voltage rating, which doesn't matter) and the new leads allowed me to reorient it along the back. I didn't really need to use the leftover lines on the ribbon cable, so I got them out of the way as well. The USB-TTL board nestles in with Tessa tape on the capacitor side and Kapton tape over the regulator...Followed up by a few layers of "alien" tape. Basically thick double sided adhesive tape. I highly suspect I will need to flow a generous amount of hot glue around there to keep that board in place as one plugs and unplugs it. Instead of trying to figure out how to safely solder to the CPU pins, I traced both TDX and RDX leeds to where they entered and exited the serial circuitry, which is now isolated by removal of the resistors, and soldered my leads there instead. As well as to the ground plane. Please don't judge my messy work, Hah! It is much much smaller to work on, even with magnification, than it appears in this image. A little hot glue or superglue will keep everything in place once I have thoroughly tested. Another sanity check and plugged everything in. Yay, it still works!... Always a good thing! ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Hmmm... Well, this is a bit disappointing... Everything is working on the inputs and outputs, but slower and dimmer on the outputs. My initial power checks showed 8.9v on the test port. But now I only have 4.6v with nothing else running. Hmmmmmm... The USB-TTL is powered by the PC, so that shouldn't be drawing any power. So now I have to figure this out, or forever run this at half power... Something I can relate with, but not approve of :P Oh well, thank heavens I still have some issue to nag at me... I was concerned I might be done thinking and have to go back to some Netflix bingeing :D I think I am going to have to double check that capacitor I replaced. It is the correct 220pf but perhaps it is not making a good board connection... Those ground planes do make for difficult soldering. I am not well versed enough to be sure, but if I messed up that capacitor, then it should affect the 5v logic (which is apparently working fine), not the 9v output port voltages... Gotta open it up again :P Edited March 16 by Gunners TekZone Quote
dr_spock Posted January 18, 2025 Posted January 18, 2025 6 hours ago, Bliss said: The original Lego PSU is 12VAC 7VA so we talk basically of 600mA at 12 VAC for the whole box... It not much... Can the Box use more amps if we connect a bigger PSU say 12VAC at 2A (24VA)? No matter USB-C or USB-A, from a computer port it is not like a PD Charger I think... I would use the USB from a computer to have both DATA and Power. But anyway, saying this, google tell me: Most computer USB ports supply 5V of electricity with a maximum current of 0.5A. So maybe not enough to use the interface at least like the spec... but still... How about wiring a USB connector directly to the 5V rail of a PC power supply? This old PC PSU lists 22A max on the 5V. Quote
Gunners TekZone Posted January 18, 2025 Author Posted January 18, 2025 (edited) On 1/17/2025 at 6:17 PM, Gunners TekZone said: I am not well versed enough to be sure, but if I messed up that capacitor, then it should affect the 5v logic (which is apparently working fine), not the 9v output port voltages... Gotta open it up again :P Well... It only took me 5 hours to diagnose and fix... (and I really was at it the whole time... I is tired)... But it turns out I DIDN'T mess anything up with the capacitor relocation... Wow And FYI, isopropanol will weaken hot glue connections, so that was easy to remove. I was getting very high resistance over the 9v line (14+kohm). And while testing, it broke at the main board joint. So I replaced it... only to have the grounds also break... AH HA!!! It was the 30 year old ribbon cable solder joints (EDIT: Actually, the solder joints were fine, the rather rigid and non-copper wire in the cable simply fatigued very quickly and snapped right at the joint). For all I know, that ribbon cable might have been a contributing factor in the serial connection??? I did so many tests, but didn't see any visible issues. Oh well, too late now, it is "improved", deal with it So anyhow, after way too much time and effort to remove, not the ribbon cable, as that all but fell off in spots, but the remaining little bits in the both board's through hole connections. I then replaced with new wire, tested voltages as good, and reassembled it. It works great! End of story... ... I hope Edited March 16 by Gunners TekZone Quote
Wapata Posted March 16 Posted March 16 (edited) Hello there ! I'm not creating a new topic because I think the solution may be here. I had a particular issue : I can see that i'm sending Data to the Lego Dacta Interface-B as the red light turn off (to think about life etc) but then... no answer. Two interface, a good null modem cable, some jumpers, multiple usb ports, a computer that is cool with serial-usb interfaces... nothing. But it look like the Interface-B was dead from the factory, despite the control check stickers. One component is upside down ! So I did solder it back but don't know how to test it, And i have a leg that lead to nowhere. Can someone check if this leg is "free" ? I have made pictures whit a light behind, because i never found a good PCB picture on the web. But let's be clear : after all the time spent, if there i;s no "eureka" solution, i would like to use the USB-TTL solution, but there is not a single picture left from @Gunners TekZone . I know how to follow electronics schematics, not how to create things from nothing Edited March 16 by Wapata correcting pictures links Quote
Gunners TekZone Posted March 16 Author Posted March 16 (edited) 1 hour ago, Wapata said: but there is not a single picture left Hello. Sorry about that... My posted pics tend to get purged as they are hosted from a free Dropbox plan, and space eventually gets used up then cleared. I do try to remove the dead links, but forgot about this one. I don't think there is a trace from that 3rd connection. I am not sure what that particular component is supposed to be... Perhaps a transistor being used as just a diode?? In my case I first tested the full serial functionality of the Interface-B by using a TTL-USB adapter to tap into Pins 22 (TxD) & 21(RxD) from the main IC 80C515. Once I confirmed that the Interface-B was otherwise functional. I connected the TTL-USB to convenient locations traced out from the main IC. I did find convenient side by side locations for such around the mid/upper left side of the board. And becasue of the whole ribbon cable rot, I simply cut all out the Serial stuff and placed the USB/TTL adapter in place of the DE-9 socket. I did have to move (replace) the large cap to make space. I hope this helps. Edited March 16 by Gunners TekZone Quote
Wapata Posted March 16 Posted March 16 (edited) Of course it does help ! Let's bring the ttl back and test that ! Okay... false start, i'm not able to put my hand on a single USB-TTL at home Edited March 16 by Wapata Quote
Wapata Posted March 16 Posted March 16 Let's call that a huge success !!! Thank you very, very much @Gunners TekZone! Now I just have to find out why i don't have any TTL converter anymore and see how to make that a little bit more sexy Oh i'm so happy right now.. this device never worked since his creation Quote
Gunners TekZone Posted March 16 Author Posted March 16 @Wapata Very nice! Another old LEGO Interface-B is resurrected. Arduinos still have purpose! OK, a Mega is a wee bit overkill, and a space hog... But still sexy in it's own way as a great diagnostic tool Quote
Wapata Posted March 16 Posted March 16 Yes. And i've also seen that i cant put everything back because there is a big red button just in the area i've used... It wasn't obvious one hour ago. So now i've have to go to aliexpress and chose TTL to USB or TTL to Bluetooth. There is 12 volts, 9Vdc but maybe a 5Vdc can be hidden somewhere Quote
Gunners TekZone Posted March 16 Author Posted March 16 (edited) 9 minutes ago, Wapata said: i cant put everything back because there is a big red button just in the area i've used... It wasn't obvious one hour ago. Ha, yes... that's why I tapped into the corner area. 5v should be fine, but I did switch my TTL-USB to 3.3v just in-case the CPU couldn't handle the 5v long term. I also replaced ALL the ribbon cable (the remaining wires were just power and GND) to make it even more flexible to assemble. Hot glue looks messy, but it holds and can easily be removed with some IPA if needed. Edited March 16 by Gunners TekZone Quote
Wapata Posted March 16 Posted March 16 If it does work great in 3.3v then it will be 3.3v too. And I've seen somewhere else that the wires can break inside the ribbon cable so I think that your idea is good, plus there is plenty space to put cables here. Plenty space too to glue the adapter somewhere and make a plate to hold a good old usb-B connector in the sub9 hole. Quote
Gunners TekZone Posted March 16 Author Posted March 16 (edited) You can go a step further and put in an ESP32 in lew of the TTL-USB... Now you have a standalone WiFi capable Interface-B that is controlled via MicroPython. https://www.eurobricks.com/forum/forums/topic/200778-project-programs-to-allow-interactions-between-old-lego-control-interfaces-rcx-lego-interface-b-others/ I have one of mine somewhat like that, only externally connected via it's normal (working) Serial interface. This one acts like an MQTT client to switch a household lamp. One of my many ideas is to (eventually) embed it into the Interface-B that currently has the TTL-USB. Then with a small switch wired to a GPIO and some additional coding, make it act as a switchable WiFi capable device running MicroPython code, or just as a simple USB Serial device for use with the usual Control Lab etc. Edited March 16 by Gunners TekZone Quote
Wapata Posted March 16 Posted March 16 I don't think I will ever learn python sadly. But there is also standalone-raspbery work made somewhere here (but out of the interface-B). https://controllab.io/ I didn't find any "real" ttl to Bluetooth to use with https://blissca.github.io/lego-blockly/ And my "good old usb-B" is obsolete... There is more usb-C converter now well... Why not in the end. Quote
Toastie Posted March 16 Posted March 16 47 minutes ago, Wapata said: Let's call that a huge success !!! Oh yes, congratulations! But what did I miss? There was this wrongly soldered tripod thingy - did you replace that? What actually made the Interface B come back to life? The Arduino soldered directly to the B's microcontroller? I am just curious. Best wishes, Thorsten Quote
Wapata Posted March 16 Posted March 16 Just now, Toastie said: Oh yes, congratulations! But what did I miss? There was this wrongly soldered tripod thingy - did you replace that? What actually made the Interface B come back to life? The Arduino soldered directly to the B's microcontroller? I am just curious. Best wishes, Thorsten Serial port use 12-15 volts and ttl 3-5 volts for Rx and Tx. But it's kind of the same signal. So with the great help of @Gunners TekZone I was able to find WHERE are those ttl signal. Then I was not able to find back my converters but learned that if you short RST to ground on an Arduino, you can skip the whole Arduino thing and use the Rx and Tx pins as ttl directly connected to the USB port. So now I know my device is working, still don't know why it never answered back in the beginning but... Whatever now ;-) Quote
Wapata Posted March 17 Posted March 17 Okay, I've changed my mind after some soldering just before going to work. First I will not use the ground anymore as it is the "high voltage ground" and will use the Sub9 ground pin 5 that is isolated from the other one. Then i will keep the Interface-B as original as possible so i will use the pin 1 and pin 9 of the Sub9 port and create an external device for the TTL to USB convertor. Like that, every single user that want to upgrade his Interface-B can do it whatever if he use the Original Null Modem Cable, a "full" Null Modem Cable, or the TTL convertor. But then i have not a single clue if you can damage to death the Interface-B if you connect a straight Serial Cable to a computer... Quote
Wapata Posted March 17 Posted March 17 17 hours ago, Toastie said: this wrongly soldered tripod thingy - did you replace that Sorry i've missread your question: i don't know what the black tripod component is but yes i did put it back in place as you can see on the second image. The multimeter said "bip" for each leg and trace... at least for the two traces i'm able to follow. It is a 4 layer PCB but this last leg doesn't seems to be connected to anything. Then it still doesn't work. Then I take out and back the component, then it still doesn't work. Then I was not able to put my hand on my mini oscilloscope (should be with my TTL interfaces) so I was thinking it's a dead end because every wire and pcb route are good. After that i've proced to create an account here because every question about old Lego electronic stuff leads here. Then i had to wait for approval, and here I am, asking for help in the very good topic because the pictures are missing. pfiouuu And somehow also seen that i'm not able to MP one of you for a side question : is it me or there is no documentation on the web about the Lego sensors (like, wiring, pinout, what are they and so on) ? I feel that the temp sensor should be PT100 but have no luck with the search button. Quote
Toastie Posted March 17 Posted March 17 @Wapata Wow, that is quite the journey you have taken! And surely tracing a four layer PCB is quite the task, if possible at all with just a multimeter or small oscilloscope. At least the "legs" of the individual components should connect to something - if they are not some type of 3 pin SMD dual diodes, where they only used one diode (here is an example: https://ae.rsdelivers.com/product/nexperia/bav99215/nexperia-100-v-215-ma-diode-switching-3-pin-sot-23/1037576). I vaguely remember (but that could be wrong, need to check) that the IR tower of the RCX used a couple similar devices and one had only two pins attached(?). With regard to PMs: You need a post count >= 10 (again, not sure about the =, it is maybe > ;) and then you can PM around. So that will be enabled for you any time soon. LEGO sensors: All the 9V sensors usually used in conjunction with Interface B are fully compatible with RCX/9V Mindstorms sensors. In this regard, Philo's homepage is always a good start (https://www.philohome.com/tech.htm) - here you will also learn about powered vs. unpowered sensors, how to do that, what they do etc. I also had some luck with googling "LEGO RCX sensor circuit diagram" (picture search only) - that will lead to quite some old, but still functioning sites. Just let me know what you are looking for specifically and I can dig through my files, handwritten pages, and so on. Others here on EB have certainly also valuable information in this regard!!! All the best, Thorsten Quote
Wapata Posted March 17 Posted March 17 1 hour ago, Toastie said: you are looking for specifically What are those temperature sensors. And by the way the link you gave me is great for the rotary sensor ! For now, all my sensors are wireless, waiting for a new spool of black wires Right now the Interface B is not working anymore. New pictures first : So the Pin5 ground doesn't work. No reaction from the device. Take out Pin5 and putting a floating wire between the PCB Ground (remember, it is a different ground) that worked earlyier make the device react. The red LED goes of but i still have n invalide answer (but some trafic into the arduino i see). Then a take of the tape because "it's not shield wire after all" but both upper solution still doesn't work. Could it be that the wire are too longs ? Is it risky to link both Pin5 ground and pcb ground on the SUB9 ? Please note that the multimeter say bip between the Siemens ship up to the arduino pins. Quote
AJB2K3 Posted March 17 Posted March 17 I'm not sure If I have mentioned this before but I power my interface With a 1500mAh 3 S LIPO battery. Quote
Toastie Posted March 17 Posted March 17 57 minutes ago, Wapata said: What are those temperature sensors. Well, if you browse through Philo's site, you'll find this section: https://www.philohome.com/sensors/tempsensor.htm It is about how to make your own, but Philo found out which type is actually very close to how the original LEGO temp sensor behaves. I doubt TLG used PT100's or something similar, they tend to go cheap (but rather) reliable. Philo also suggests types of NTCs. Oh crap - Interface B gone again - that is very bad. I am just too busy right now with work stuff - it is the second round of exams (you take when the first try, well, somehow "failed". Or you want to improve. Generally, people becoming increasingly nervous as they have only three tries ... which I hate, exams are good for almost nothing, but that is my very personal view. I am powering my HC05/TTL2Ser converter also from the Interface B as power source, I need to find that stuff as well ... Best wishes, Thorsten Quote
Wapata Posted March 17 Posted March 17 Oh... I did already seen (and forgot) this page I'm taking out the ribbon cable right now. I've seen the green 9v led flickering. I don't need doubt so the big replacement is coming. Quote
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