Hi - I also built the project and can offer a couple of comments what you found:
#2 - I am not surprised that the pads came off. I ended up soldering some tiny 28 gauge wire to each of the pads, and then soldering the LED to the wire. This method also gave me flexibility in mounting the LED. I ended up gluing it into the hole on the assumption that some (child) was going to try press on it like a button.
#3 The 3.3 volt signals you found are probably the output from the MSP430 microcontroller and will not drive much current, so you might want to be careful what you hook up to them. I believe that is why they had F0 and F1 connected to the input of the buffer IC. the output of the buffer is at the voltage of your battery and will drive more current, like a relay. I added a transistor to the output of F2 so I could drive more current with that as well: a relay to trigger a horn on a sound card
I will try to draw up a schematic of what I did and post it on this forum.
I've also just built a version of this project but made a few changes that may be of interest to others. While the transmitter did just what I needed, I wanted to put the receiver into a larger locomotive that already had a track-powered DCC decoder (a Bachmann Shay with a QSI decoder). I therefore substituted a higher power motor controller (5A L2603) and wrote my own receiver software so that the wireless DCC signal is simply passed on as the power signal to the existing DCC controller. Essentially the receiver acts as a DCC booster, simply forwarding DCC packets and thus doesn't need its own address or other CV values, nor outputs to lights or sound.
I can post the software and schematic if there is interest.
I would be interested in a schematic and the software.
Thanks!
Tom
Definite interest here! Thanks.
OK, I've uploaded the machine code, source code (C) and schematics, along with some photos. Do let me know if you've questions, suggestions or improvements.
https://drive.google.com/folderview?id=0B6wnj-3FTWd4STNSSDlhVzBYUEE&usp=sharing
Cheers,
Brian.
Brian
Thanks a lot!
I will give it a try.
Thanks very much for this Brian. Nicely commented coding too. If I had the skills I would be all over this to modify it ( I'm more stuck at the Arduino level of programming - I can do a lot, but not this ). I still think this has the potential to be a great open source project. Now maybe if we could get this thread renamed or restarted - "Will Mark and Vince..." doesn't seem to convey the content
Hi all and thanks for the Jr Operator help from this blog. In this hobby, I am principally a scratch builder and certainly challenged when it comes to electronic. I have successfully built my first throttle. By successful, all I know is that as a result of following all the instructions, the green LED functions as documented.
I am now about to build my first decoder. I have downloaded the updated article and schematic diagram but I have one question: I don't understand exactly what to do when following the phrase 'JP needs to be modified by cutting the trace with a sharp knife'. I know the location on the PCB but am unsure about the specific action or procedure. Can someone please provide some specifics about that instruction?
In advance, thank you.
John
If you look closely at the PCB you will see a line between the gold pads on some of the jumpers, such as the fourth one from the bottom labeled '1'. This line is the trace on the PCB that electrically connects the pads as a 'default' jumper. You need to break this trace on this jumper, replacing it with the wire you will solder to jumper '3'. You break the trace by cutting it with a sharp knife - you will cut right through the read coating and the copper trace beneath, so there is no electrical connection between the pads. If you have a multimeter you can check that you've broken the connection. Then solder a wire across the pads on jumper '3'.
Photo 4 in the article shows the change to the jumpers. If you look closely you can see the scraped area between the pads of jumper 1.
Cheers,Brian.
Brian, Thanks a ton :)
Brian new to this but not to DCC, What would this program need to change function 1 to f3 momentary?
Have built 2 original copys and work fine
A request to the programmers in the crowd. I would like to change the F1 on the decoder so that it works like F2, a momentary 'on' when the button on the transmitter is pushed. Right now it toggles on and off every time I push the button, operating like F0. Does anyone know how to update the code to do this?
The other thing I would like to do is to add 2-3 more buttons on the transmitter to control 2-3 more functions on the decoder. these would operate the same way. Push the button on the transmitter and the decoder turns that function on while the button is pushed.
Thanks
Changing F1 to momentary operation, instead of toggle, requires a change to the transmitter code as this is where the state of the functions is determined. It isn't a difficult change, but without source code it gets messy. It would be helpful if the original source code were published.
Adding more buttons to the transmitter gets a little tricky as there are not many input pins available on the processor. Probably the easiest change is to use the three pins that are currently used to select the radio channel, which would mean that a software patch would be needed to change channels (just like changing the decoder address). Would that be workable? Both transmitter and decoder software changes would be needed to make this work.
Thanks for your reply Brian. I guess all we can do is appeal to Mark and Vince to post the source code so it can be modified.
In terms of the extra buttons, I will probably want two. I have built three transmitter/decoder sets, each with a different locomotive address using the instructions in the article for modifying the first line of the code to change the address. So I am fine modifying the channel with software as well, as I really need to control 2 more functions with the transmitter.
Thanks for reply
When I started to build these units I had a problem about jumpers I emailed Mark and a coulpe weeks later he answered me but I found problem and fixed before he got back to me. I later asked him about changing functions and have never gotten a reply.
If more of us ask editor Mark maybe we can get source code.
genera
ALL
Maybe we can get a reply from Mark Buccini about the source code by asking him directly
HIS email address is mbuccini@sbcglobal.net
If anyone gets an answer let us all know PLEASE
Gene
Hello all,
Marc Horovitz called and spoke with Marc Buccini last night, regarding the source code. Mr. Buccini is not interested in releasing the source code for a variety of reasons. However, he is willing to answer questions at the email Gene listed above.
Rene
Rene Schweitzer
Classic Toy Trains/Garden Railways/Model Railroader
Hello again,
I have finally built both a transmitter and decoder but they're not functioning. I have programmed each using the default files (m430T0.txt & m430D0.txt) with the default loco address of 03 and did not jumper the default channel of 02. The throttle LED gives feedback as designed. The SMT LED on the decoder flashes in unison with the Launch Pad until the program is loaded. I hook everything up to what I know is a working motor block but no throttle response.
The only thing I'm not sure of is step 7 of the decoder. Since I soldered everything according to the updated circuit diagram, I assume I did everything referenced in the first paragragh of step 7 but I do not understand the second paragraph. There is nothing in the circuit diagram that shows what is described in the dialog about pairing the entire columns of prototyping-through-holes for the VDD, GND, and third columns.
Have I missed a crucial step or do I need to do some other type of diagnostics? If the latter, where do I start?
In advance, thanks.
This is very disappointing. It sounds like Marc may be planning to produce a commercial product and is afraid open source would erode his customer base. In reality this is not true. Even Microsoft is moving more towards open source with making .NET open source. And Tesla is letting everyone use their patents. If Marc (and GR Magazine, as publisher of these plans) wants to help the DIY aspect of the hobby I would urge them to reconsider.
there have been several questions about wiring the back of the decoder board and there are no diagrams in the article about this. Here is a diagram of the board with the three necessary wires shown in blue. The view is from the front, but these go on the back of the board and connect all of the pads / components that they touch together. You can just bend over the leads from the capacitors and lay them down along the row of pads and use that as the wires, soldering them to all of the pads/components that they touch.
https://onedrive.live.com/redir?resid=4EA7451EA9DFF0!5174&authkey=!ABMvNjXJkmobHhU&v=3&ithint=photo%2cpng
Marc Horavitz has tried to convince Mark Bucinni to release source code . I have personally talked with Marc Horavitz about this but really nothing GR can do.
I have been working on source code. Its binary coded machine language and will be decoded in full eventually.
IF Marc Bucinni is planning a commercial project this will hurt him more by not releasing .
The DCC parameters were released by Lenz years ago to NMRA so anyone could mfg compatable equipment. Thats the beauty of DCC.
THat should be all that is necessary to make units work. I have built 7 decoders now and work fine. One of problems with system is if you cycle power too fast you will have to reflash the 430 chip
Gene,
Are you interested in collaborating on some open source code? I've made a start based on the C code I previously posted to this forum (receiver side with DCC output), and plan to work on the transmitter side this month.
Do you have anything yet to share?
Brian,
That's awesome that you've already started on open source code! It looks great! Would you consider putting this on Github or Bitbucket to make it easier to fork the code and issue pull requests? I'd like to collaborate on this as well.
Ben
I've posted the DCC receiver code to GitHub at https://github.com/bdharrison/wireless-dcc
I hope to post a transmitter version later, and any collaboration is most welcome.
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