 | | DCC for the RCX
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| Hello All, I've completed a new bit of firmware that enables the RCX to act as a DCC Command Station. For those who are not familiar, DCC (short for Digital Command Control) is a means of sending electrical signals over model railroad tracks to (...) (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains) !!
| | | | | Re: DCC for the RCX
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| (...) Mark, nice work, this is very sweet. Makes me wish I had some DCC LEGO train motors even more. I guess one day I need to get off my fanny and put some together. I will bookmark this for sure, since I'm sure I'll be wanting to use it in the (...) (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains, FTX)
| | | | | Re: DCC for the RCX
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| (...) Oh My Goodness! This is what I've been waiting for--when I priced out DCC controllers, they were 200+ CDN... If I can get one of my many RCX's to do it, well that's entirely another matter. When I originally did the research and found the cost (...) (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) As I run 12v stuff I dont know the 9v motor good enough to comment on the capacitors but I dont think it's that good an idea to use a resistor to drop the voltage. Use one or more (zener)diode's instead. Esger (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| <snip> (...) Hey Esger I'm not an electronic specialist by any stretch of the imagination (though not by lack of trying) But commercially available DCC controllers and stuff mostly run at 12 volts (from the research I read), but the RCX runs at 9 (...) (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) I (...) resistors (...) goes (...) run (...) the (...) isn't (...) reduce the (...) David, When I installed my first decoders (Digitrax DN121), I omitted the capacitors, figuring if the buzzing was annoying, I could always add them later. As (...) (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| In lugnet.robotics.rcx, Mark Riley wrote: <snip> (...) Mucho appreciated Mark. The Diode--any diode will do? and just solder it across the connector output? Take care, Dave (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) output? Dave, I used a 1N4002. It's a fairly common 1 amp switching diode. Here's a picture from my latest decoder install: (URL) that the banded end of the diode gets the blue lead from the decoder. The unbanded end gets the white lead. If (...) (21 years ago, 28-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) I don't install them either, and I have done something like 30 motors so far. (...) True, but ONLY if you are just going to use the RCX as a output. You can dial the voltage that DB100's (and most other Digitrax) boosters put out to a exact (...) (21 years ago, 29-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) Resistors work fine due to the relative difference in cost. The accessory outputs of the earlier decoders are 100ma or so @28V or less, so at most you are dealing with 2.8 w loss (or 100 ma current draw). In order to drop from 14V to 9V, you (...) (21 years ago, 29-May-03, to lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) Huh??!? Your basic resistor can only handle 1/4 watt (0.25W), so your worst-case 2.8W is more than ten times the rated maximum current. Even dumping an "insignificant" 0.5W across a resistor is probably not adviseable unless you are also (...) (21 years ago, 29-May-03, to lugnet.trains, FTX)
| | | | | Re: DCC for the RCX
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| (...) I'm no electronics engineer by any stretch-- A diode, iirc, allows DC current to 'flow thru' in only one direction. What would a diode do across the output on the top of the train motor? And why would one be good for 'inductive' loads such as (...) (21 years ago, 29-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) The problem with inductive load is that when current is interrupted, they generate large voltage spikes with reverse polarity. The diode absorbs these spikes and avoids destroying the driver... Philo (21 years ago, 29-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) Sorry, my earlier post should have been more clear. I was just commenting on the fact that in general a resistor is _not_ a good way to reduce voltage to a train motor. And you recalled correctly: diode's are "one-way". Thats why you need to (...) (21 years ago, 29-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) Hi Dave, no you wouldnt need any resistors or diodes. Esger (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) I forget if I already replied with how nifty this is. I spotlighted it, I put in a news article at ILTCO (we're having some domain problems right now, a temporary url is iltco.northcomp.com) and I added it to the .trains header That ought to (...) (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) I don't know about you, but I tend towards .5W or bigger for most of my resistors, and diodes have exactly the same problem if you use them as a voltage drop. Load is not really signifigant on a 5A booster (soon to be 10 amps total...2 (...) (21 years ago, 30-May-03, to lugnet.trains, FTX)
| | | | | Re: DCC for the RCX
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| (...) put in (...) Thanks, Larry, and thanks to all who posted or emailed. (...) one (...) Or is (...) It's important that the motor outputs share the load as evenly as possible. A stalled train motor can draw as much as 750ma, while a single motor (...) (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| i have a question concerning how the DCC signal is sent Is it just sort of a "rider" on top of the power similar to X-10 home automation signals? If so could not the RCX be protected with diodes and used in conjunction with a standard train (...) (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| In lugnet.robotics.rcx, Esger Abbink wrote: <snip> (...) Perfectly understood. Thanks! My problem has always been that I wanted to get into electronics, but all those resistors 'n such used to have all these coloured stipes to denote the different (...) (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) hmm, color codes and being color blind dont really match well indeed... as far as electronic components go, I'm just a hobbyist. My day job is programming ;) Esger (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) Hey Mark, I posted earlier in a new thread praising the greatness of this, but I have a few additional questions that I thought I'd just ad to this thread-- I converted 3 LEGO motors with the micro-controller, and now have 3 diodes (at least, (...) (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) Got the programming part--all motors on differnt Loco #'s--figured it out. I wouldn't mind building that Ack circuit though, so any advice on using hte LEGO diodes would be helpful. I'm having a great time--and by the way, as mentioned on the (...) (21 years ago, 30-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| Hi Dryden, DCC sends information to the decoders by flipping the polarity of the power supply in a specific timing sequence. So, it's not like the X-10 protocol. To get more power to run more locomotives, you need something called a DCC booster. The (...) (21 years ago, 31-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) have a (...) diodes (at (...) I think those are probably some sort of noise suppression device, not diodes. At least they don't "diode" when I hook'em to my meter. Another clue is there's no band on one end. Could be one of those "free to good (...) (21 years ago, 31-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) When you say LEGO diodes, are you sure you aren't referring to the thermistor that some DCC mods have you remove? Maybe I'm confused of course... whose conversion instructions did you follow? (21 years ago, 31-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) I thought that the little doohickey that goes across the motor inputs on the electric motor in the housing was a diode--don't quite remember where i picked up that idea, but a 'noise reducing' thing makes more sense. Anyway, i'll go get a (...) (21 years ago, 31-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| In lugnet.robotics.rcx, Mark Riley wrote: <snip> (...) This is what I did to make it work for me... All my microcontrollers out of the bag were on "loco 3"--that is when I used the remote, all 3 motors worked when I used the C up/down and 3 button (...) (21 years ago, 31-May-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| I just converted my first engine to DCC yesterday and started playing with LDCC 1.01. LDCC is fantastic! Thank you, Mark! I installed an AD330 N-Scale decoder from Model Rectifier Corp according to the directions on Tom Cook's site. At 0.8 Amps this (...) (21 years ago, 9-Jun-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) LDCC (...) to the (...) to (...) this (...) of (...) index (...) I (...) the (...) Great, Chris, I'm glad it's working for you - and with another brand of decoder, yet! (...) worked (...) mode and (...) parameters. (...) of (...) meanings (...) (21 years ago, 9-Jun-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (...) One way is to mount one or more magnets on the underside of the train with their N-S pole oriented across the width of the train (to differentiate it from the couplers of just any old train) and then sense these specially-marked train cars (...) (21 years ago, 9-Jun-03, to lugnet.robotics.rcx, lugnet.trains, FTX)
| | | | | RE: DCC for the RCX
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| Mark, would it be possible to share the code of your DCC controller, I am the author of pbForth and would love to add the driver to the pbForth library. I've also got a servo driver in pbForth already. Too bad Hitechnic is out of business. Their (...) (21 years ago, 9-Jun-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| Hi Ralph, I should be able to extract the source for the low level driver routines this week. If anyone else is interested, please email me. Note for BrickOS users: it's not simply a matter of plonking the routines into a program. The kernel will (...) (21 years ago, 9-Jun-03, to lugnet.robotics.rcx, lugnet.trains, lugnet.robotics.rcx.legos)
| | | | | Re: DCC for the RCX
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| (...) That would be ideal, IMHO. It would allow, among other things, LNP to be used for PC to LDCC communication. At IndyLUG, we've been wishing for DCC L-gauge since inception. The word "thanks" simply doesn't cover it, Mark. Congratulations on (...) (21 years ago, 10-Jun-03, to lugnet.robotics.rcx, lugnet.trains)
| | | | | Re: DCC for the RCX
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| (Sorry, did FUT to .legos, but didn't post to it. I'm such a newbie!) (...) (21 years ago, 10-Jun-03, to lugnet.robotics.rcx.legos)
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