The ERR Mini Commander Replacement Project

The idea came up to build a suitable replacement for the ERR Mini Commander that is no longer available.  This is a thread to kick around the concept and see if it makes sense, and what capabilities it would have.

Some basic starting thoughts, feel free to expand or call into question any of my assumptions.  Remember, this has to be somewhat limited so we can make it happen for a reasonable price.

  • Unit to be based on the Lionel R2LC/R4LC board with a small motherboard with additional components to add functionality.
  • An H-Bridge motor driver chip to be connected to the Forward and Reverse PWM outputs to drive a small motor with the throttle outputs.  I've tentatively identified the MPS MP6513 as a possible choice, .8A motor drive with full thermal and over-current protection.
  • A latching relay or circuit to allow persistent control by use of the coupler outputs.  I've tentatively identified the Kemet EE2 series 2-coil latching relay, it has 2A capability and is a DPDT part.
  • Capacitors across the lighting and smoke outputs to allow the use of LED's without load caps external to the board.  Perhaps a series resistor to allow direct drive of LED lights from the lighting outputs.
  • Connector pads for all the above functions on the board.

That's my starting grid, let's hear some ideas.

Original Post

That's the idea, but we're still working out the details.  I just want to kick around what we can do fairly easily to replace some of the functionality we had with the old ERR MC products.  Without adding a uP, I think stuff like the voltage control and timed activation that the MC had may be difficult.  It should be easy to do some simple stuff and accommodate some command control applications.  My sense is significant work went into the software of the MC-ACC, not sure I want to try to duplicate all of that at this juncture.  I'm trying to leverage the capability of the R2LC board and add some functionality so it can be used.

gunrunnerjohn posted:

That's the idea, but we're still working out the details.  I just want to kick around what we can do fairly easily to replace some of the functionality we had with the old ERR MC products.  Without adding a uP, I think stuff like the voltage control and timed activation that the MC had may be difficult.  It should be easy to do some simple stuff and accommodate some command control applications.  My sense is significant work went into the software of the MC-ACC, not sure I want to try to duplicate all of that at this juncture.  I'm trying to leverage the capability of the R2LC board and add some functionality so it can be used.

Sounds like a plan John!!

Blake Morris posted:
gunrunnerjohn posted:

That's the idea, but we're still working out the details.  I just want to kick around what we can do fairly easily to replace some of the functionality we had with the old ERR MC products.  Without adding a uP, I think stuff like the voltage control and timed activation that the MC had may be difficult.  It should be easy to do some simple stuff and accommodate some command control applications.  My sense is significant work went into the software of the MC-ACC, not sure I want to try to duplicate all of that at this juncture.  I'm trying to leverage the capability of the R2LC board and add some functionality so it can be used.

Sounds like a plan John!!

Just some simple remote control action.

John Graser posted:

Here would be my wish list:

  • 2 output for 2 couplers
  • 1 output for action (dump/throw /etc)
  • 2 outputs for lights (optional)

I figure that all the R2LC outputs will be available, so those are all accommodated.  Any functions we tie to some of the R2LC outputs will be in parallel with their primary function.  For instance, the couplers might be driving a latching relay, but you'll also be able to use them for couplers.

The one tricky part is having a timed output like the MC, that requires we decode the serial data and have soft configuration.  All possible, but beyond the scope of what I plan on starting with. 

One trick is keeping the connections to the board compact enough to get all the stuff on and off the board!

CBS072 posted:

Can you make it  work in a dummy engine for TMCC control, lights, couplers, sound and maybe smoke?

A F3B/F7B may only need smoke and sound?

I’ll second this.  Question, you won’t be stepping on anyone’s patent with this?

CBS072 posted:

Can you make it  work in a dummy engine for TMCC control, lights, couplers, sound and maybe smoke?

A F3B/F7B may only need smoke and sound?

FWIW, this is the application I'd be most interested in. I've never used the coupler function on the Mini Commanders I have installed but the ability to use one of the HC outputs for smoke has been important. 

Of course sound capability is kind of the Holy Grail; I've had to use ERR's little dummy engine board for that. Pardon my ignorance GRJ but I don't know whether the components you are thinking of using allow for sound.

ERR's Softset programing was very convenient but I could live without that.

CBS072 posted:

Can you make it  work in a dummy engine for TMCC control, lights, couplers, sound and maybe smoke?

A F3B/F7B may only need smoke and sound?

Sure, it'll have all the capabilities of the R2(4)LC, which includes all of those things.

Jan posted:

What are the capabilities of an R2LC/R4LC?  Is there a datasheet or specification available?

None that I'm aware of, but the capabilities are pretty well known.

superwarp1 posted:

I’ll second this.  Question, you won’t be stepping on anyone’s patent with this?

Nope, we're using the Lionel TMCC receiver.

Hancock52 posted:

FWIW, this is the application I'd be most interested in. I've never used the coupler function on the Mini Commanders I have installed but the ability to use one of the HC outputs for smoke has been important. 

Of course sound capability is kind of the Holy Grail; I've had to use ERR's little dummy engine board for that. Pardon my ignorance GRJ but I don't know whether the components you are thinking of using allow for sound.

ERR's Softset programing was very convenient but I could live without that.

Sound as far as this module is concerned it simply having the capability of feeding a standard sound board, that just takes power and serial data.  If a standard TMCC locomotive could do it, we should be able to support it, the R2(4)LC is where all that happens.  What I'm visualizing is simply a motor driver (H-Bridge) chip, a latching circuit of some kind to leverage the many times unused coupler outputs, and perhaps a couple components to allow direct LED attachment for the light outputs.

What I'm really fishing for here is if there is some other good ideas of things we might add that I haven't thought of.  Obviously, one of the requirements is that they don't take a lot of parts to do as we're also trying to keep the package pretty compact.

I've prototyped out a replacement for the Mini-Commander ACC or HC, using an Arduino module and an HC-12 radio receiver.

It doesn't receive TMCC signals directly; a single HC-12 connected to the command base broadcasts the TMCC commands to all the others. So it's not a drop-in replacement for the MC.  But it ran about $12 in parts; less if I hadn't used a commercial power supply module.

Of course, in addition to driving triacs like the MC, it could be programmed to drive servos or any other circuitry you wanted.  And you could program it for as complex behavior as you like... just need to think of some applications!

IMG_1668

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Professor Chaos posted:

I've prototyped out a replacement for the Mini-Commander ACC or HC, using an Arduino module and an HC-12 radio receiver.

It doesn't receive TMCC signals directly; a single HC-12 connected to the command base broadcasts the TMCC commands to all the others. So it's not a drop-in replacement for the MC.  But it ran about $12 in parts; less if I hadn't used a commercial power supply module.

Of course, in addition to driving triacs like the MC, it could be programmed to drive servos or any other circuitry you wanted.  And you could program it for as complex behavior as you like... just need to think of some applications!

This has possibilities, I'm not wedded to the R2LC approach, it just seemed to be a simple means to an end. 

I think one key item is to try to keep it compact.  I know you can buy the Arduino processors as a separate part, so perhaps building a board around the chip would keep it to a reasonable size.  For most of our applications, you wouldn't need all the extra stuff that comes on these boards.  Of course, making a sandwich with something like an Arduino Nano might be an option as well.

The one downside of this approach is it requires a lot of up-front work to get started, we would have to decode the serial data and sort out all the timing issues of the TMCC protocol.  I've done a bit of that, but there's a lot more to do for this to be useful.

I commend John for the effort he's putting into developing this new board, and maybe I'm unaware of something significant here, but why does John need to do this? Why doesn't or won't 3rd Rail make a mini commander available just as ERR did when they were in business? Why should John have to, as the expression goes, "reinvent the wheel" on this? Also, with John doing this, will he need to jump though hoops with Lionel to get permission to sell this board to consumers once he develops it?

I think it's likely Lionel dragging their feet in licensing the MC products.  Since my project would be using an off-the-shelf R2LC, there should be no licensing issues.  Also, Scott at 3rd rail may not see enough profit in the MC line to make business sense, that would have to be a question for him.

not sure if this would effect the size of the board, but could this be a solderless board. or at least have the output wires already attached and color coded for ease of instalation for dummies. 

if this gets built I am all in. wish I would have gotten some from err when they still made them. just always thought they would be there. 

 

Roger g.

Well, the solderless aspect runs up the cost of the board, someone has to do the soldering.  Adding terminal strips increases the size as well.  If we use JST connectors like the ERR boards did, then you have to make the cable assemblies as well, all this increases the cost.

My concern is if this gets too fancy, the cost and effort to make it will result in it being too expensive to consider for many projects.  We already have to obtain an R2LC for it out of the gate.

I would like to have a single output that is turned on and off by AUX 2 that would have a half-wave positive output for forward and a half-wave negative output for reverse. This single output could be used for front headlights, rear headlights, dual-color marker lights, and cab lights. I have made several modules to do this
using relays (would be better if solid state). It only requires a single wire to be run from a tender to a locomotive or a dummy to perform all four functions.

 

SCHEMATIC

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You can program a cab light and the smoke output will toggle with direction, that would to the function you're looking for.  The great part is you can drive the headlights and directional markers from it.

Gents,

I have good news. Sunset Models / 3rd Rail has been approved to produce and sell the MiniCommander line of electronics. Of course we have to order these for production which can take several months to obtain. We will put them back up on our web site shortly. Those with current reservations for these will remain in our files for invoicing when the product becomes available.

Regards,

Scott Mann - ERR / Sunset Models / 3rd Rail

 

Scott, how do you specify the code version for the Mini Commander II?  There are three software loads, one with couplers, one with incandescent lights, and one with one incandescent light and a smoke control.  In the old ERR listings, they had three entries for the three different options.

I'm very happy to see you doing this.

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