Rapido B36-7 Decoder Mapping

[CPRail]

Hi Group,

Referencing my previous topic on the Rapido B36-7 and it's mapping (https://rpug.pdc.ca/index.php/topic,1572.0.html), I just got a copy of the ESU non-sound decoder file from Rapido. Does anyone here have the ability to read it and figure out how they mapped Function 13 for the SP Gyra-lites? I'd really like to get this unit completed.

[G8B4Life]

Possibly. Reading it is easy. Explaining what they did and translating to something for RailPro will be harder . Where is this ESU file located? Did you download it somewhere or did Rapido send it to you?

- Tim

[CPRail]

Hi Tim, Rapido sent it to me. Where shall I put it on RPUG for you to delve into the mysteries?

[G8B4Life]

Well if Bill doesn't have an issue then right here in this thread I guess. Once I've downloaded it I can remove it from your post if needed.

If either you or Bill has a concern you can zip the file with a password and PM me the password.

- Tim

[CPRail]

I have no issues with attaching it here.

[G8B4Life]

Well, it's as I thought from the original thread; The Gyralight operates on a logic level output from the LokSound decoder. This means as of right now you can't power it directly through the 21 pin interface with RP.

This is the function mapping for the B36-7 from Rapido. As you can see for the entries with F13 in them the Gyralight is on Aux11 (forward) and Aux12 (reverse). These are pins 6 and 5 on the 21 pin decoder.


Click image to enlarge

Now the confusing thing with whats in your photo's from the other thread is that while U+ is positive and has a red wire. X11 and X12, being logic level should also be positive but they, along with X10 (the emergency light) have black wires. Not that many manufacturers follow any colour convention when it comes to wiring but it's not helpful in figuring out whats what. I also don't see any connection to ground on the board.

To really work out what's going on you'll have to unscrew the Gyralight board and see what's going on the underside.

I still solidly suspect you'll have to hardwire your own Gyralight in. It may be possible to modify the existing board but until we know what's what with it it's too hard to say.

-Tim

[CPRail]

Thanks for reading the file Tim. I'll try and get some photos of the Gyra-lite board tonight so we can continue delving into the mysteries...

[CPRail]

Sorry for the delay in getting the photo of the Gyra-lite board, but better late than never. The Front Gyra-lite are the copper wires from X10 and X11, along with the corresponding red wires from the U+ tab.

[G8B4Life]

Took me a while to figure out what was going on here, your photo is of the small circuit board in the shell which I had forgotten about and I was talking about getting a photo of the underside of the small circuit board attached to the chassis! You don't need to do that now as I've worked out that the two little board are just a "plug and socket" arrangement so separating the shell and chassis is easy.

Anyway, there are no transistors on the little board so that means they must located on the decoder motherboard, on the underside as I see none in your photos of the decoder motherboard. This then makes sense of the wiring to the Gyralight and emergency light but unfortunately makes wiring just a bit harder for you.

Because we can not control logic level with RP without a lot of extra circuitry that means you can't just hook the LM up to the 21 pin adapter and off you go, you will have to hardwire the LM for the Gyralight and Emergency light. The good part is you should be able to wire the LM directly to the little board on the chassis. You will very likely need to put appropriate resistors in line because I don't know where the existing resistors are; they could be on the motherboard (which you'll bypass) or it might be at the LED's themselves. You'll have to check carefully. Do you have a multimeter?

So the blue wire would go the U+ pad on the little board and the outputs of your choosing would go to X10, X11 and X12 on the little board.

- Tim

PS, now I'm wondering why X10 and X11 only have one set of wires each and X12 has two?

[CPRail]

Hmm, good question Tim. Let me take a peek this afternoon and see why X12 has two wires.

Stay tuned.

[CPRail]

Okay photo time!

If this worked there should be 6 photos attached:
One each top and bottom of the Gyra-lite board in the shell
One each, top and bottom, of the Main 21 pin board in the loco
Finally, 2 shots of the X12 wires - I traced them and they go to the rear Gyra-lite.

Pardon the tweezers in the shots, I needed something to hold the boards in position to take the photo.

While I would love to have both front and rear Gyra-lites, I only need the front ones. I have no operational need for the front red emergency light, but if I can make it work, why not?

[G8B4Life]

Hows your soldering skills? It's doable to keep the existing motherboard and use a 21pin adapter but you've got some work to do and the only outputs the adapter can power is the headlights and the front ditchlights (depending on the adapter you have).

It's as I thought. See all those little items labelled Q1 to Q8 on the bottom on the motherboard? those are the transistors to "amplify" the logic level outputs from the Loksound decoder to make them capable of driving LEDs, lamps etc. It appears all the resistors are on the motherboard as well. This is a plus and a negative. Negative because we can't use them with the adapter and plus because we can easily bypass them.

What you will need to do is for each item in the table that has a logic level output is (ignore the transistor in the table, I was just guessing which transistor was for which output):

Unsolder the wires between the pads between the little boards (on the chassis) and the motherboard and solder on a wire from the LM to the pads on the little boards. You'll need to put a resistors inline as well. U+ will need to be connected to the blue wire on the 9 pin harness.

Table 1 : Rapido B36-7 - LokSound Auxilliary Outputs

Output	Output type	Programmed effect	Transistor (guessed)	DCC mapping
X1	Power	Ditchlight Type 1 (alt phase)		F6 - Ditchlights (Front)
X2	Power	Ditchlight Type 1		F6 - Ditchlights (Front)
X3	Logic	Dimmable Headlight	1	F11 - Class lights (Rear)
X4	Logic	Dimmable Headlight	2	F19 - Numberboards
X5	Logic	Dimmable Headlight	3	F11 - Class lights (rear)
X6	Logic	Ditchlight Type 1	4	F6 - Ditchlights (Rear)
X7	Logic	Ditchlight Type 1 (alt phase)	5	F6 - Ditchlights (Rear)
X10	Logic	Oscillating Headlight	6	F17 - Emergency light
X11	Logic	Gyra light	7	F13 - Gyra light (Front)
X12	Logic	Gyra light	8	F13 - Gyra light (Rear)

                              

or, as much as I really don't want to say you might be able to use a decoder buddy from nixtrainz and use the adapter with that and scrap the factory motherboard all together.

You could also, if you feel macho enough just make a new "motherboard" from plain PCB or stripboard and go from there.

-Tim

[CPRail]

Hey Tim,

After reviewing your message and looking at the pics again, I'm thinking that soldering change plan is beyond my skill set. Heck, I'm amazed every time I can get a loco to work on RailPro.

I'm okay soldering, but fiddling with teeny wires is my nemesis. There's a reason the 4 Rapido SW1200RS units I've converted to RP don't have any working lights.

Also, I must be the only person on the planet who couldn't figure out how to use a Decoder Buddy, so I'm guessing that's not an option.

I'm using what I believe are TCS 21 pin-9 pin harnesses (I got them from Bill).  Could I use any of the function wires on the 6 pin side to connect to the wiring going to the Gyra-Lite board? I'm okay with severing the connections from the 21 pin motherboard to those wires and hooking them up to the 6 pin side, even if I have to wire in a resistor. There's enough room to do that kind of work.

[G8B4Life]

Hey Ian,

Sorry, I totally missed your reply! Anyway, yes, what you asked is what I said you'll need to do.

I don't know which version of the TCS 21 to 9 pin adapter board you got; the old version just has pads for the 9 pins but the new version has a whole bunch more pads. If you have that version just ignore all the extra pads as we can't use them.

So, on the 9 pin side the adapter will power the front and read headlights, and should also power the front ditch lights (Output 3 and 4 on RailPro).  For everything else this is what you'll need to do:

On the gyra board that attaches to the chassis (not the one in the shell) unsolder/sever the X8/X10, U+/X12  and X11 black wires and solder an output wire from the 6 pin to each. A resistor will likely need to be soldered inline to each of them.

If you have a multimeter / voltmeter you should test the U+ red wire on the gyra board to see if there is connectivity or any resistance between the pad on the Gyra board and the blue wire on the adapter board (just put the harness on the motherboard without the LM attached). This is the common and it should be straight through with no interference.

Hope that's all explanatory enough.

- Tim

[CPRail]

Hi Tim,

Okay, sounds easy enough. Just need to have enough time where the bravery/insanity levels are to attempt it. Maybe this weekend.

Of course, She Who Must Be Obeyed may have other plans...