Frequently asked questions


My locomotive stalls intermittently. What should I do?

Most stalling issues and resulting loss of power is caused by dirty tracks or equipment. Microscopic dirt, debris and corrosive forces of nature over time can cause your track and locomotive wheels to gather grime and loss of contact for short periods, resulting in less than optimal performance of your locomotive. LocoFi™ decoders are equipped to help you tide over the smallest of these issues, with the help of an on board capacitor that keeps the decoder "alive" during such short interruptions. However, to avoid the longer power interruptions causing the board to cut out, here'a list of few recommendations we have gathered over time to help with such issues:

  1. "Dirty" the track some more. While we all know keeping the tracks clean using various methods like rubbing alcohol, cleaning car, etc., it eventually becomes a regular maintenance routine. What we have found instead is that the conductivity improves far more by spreading a conductive material like fine graphite over tracks than actually cleaning them! Further, once it's all over the tracks, the tracks are prevented from getting oxidized by air, micro sparks, etc. leading to a longer lasting effect such that you don't have to do it again and again that often. See the links below for more info:
  2. Make the wheels smooth and shiny. This is especially true with sintered wheels of Athearn BB types. Read the following wonderful link (there's a link to even more wonderful video in there by the author) and run your loco on graphited track (see above) for ultimate results:
  3. If you are still having issues, the next weak chain in the link is the pickup wipers or the contact points from the wheels all the way to the soldered wire joint. For such cases, the best solution is to use a drop of conductive lube at such joints after cleaning them thoroughly. This will ensure that even if there is something loose in that assembly, the conductive lube will keep it conducting.

I get loud static buzzing from speaker as soon as power is connected. What is going on?

Are you using an older DC power pack? Some older power packs put out what is called "rectified AC" which is not pure or "clean" DC. We highly recommend using a high amperage "clean" voltage regulated power supply to achieve maximum performance. Alternatively, a suitable electrolytic capacitor at the output of the "rectified AC" power supply can filter out most of the "noise". Please watch this video to learn more on how to do this. WARNING: Please heed all precautions while working with high capacity high voltage capacitors. Connecting them with incorrect polarities can lead them to vent off gases and splatter liquids, sometimes even causing explosions. Capacitors are energy storage devices and their improper use can lead to serious injury. We recommend connecting a bridge rectifier rated for suitable voltage and current (e.g. KBP310) and 4700uF 50V electrolytic capacitor. See schematic below.

I have tried multiple times but can't add my loco to the network. Why?

There can be several reasons for this. Please download our Android Connectivity Issues guide that will help you get past these.

Why did my sounds stop working suddenly after a 'Factory Reset'?

While we have not seen it, but because a couple of customers seem to have reported this issue, especially after a 'Factory Reset', here's how to get the sounds back.

  1. Take the microSD card out. See how to here: Replacing microSD card. WARNING: Please make sure that the module is not powered during the entire time working with the microSD card. Please power off the module before taking the card out and power it back up only after the microSD has been properly seated and its cover locked in place.
  2. After plugging it into the computer (you may need to use the supplied SD card adapter), copy the contents of the microSD over to a temporary folder on your computer.
  3. Download the SD Formatter software from here: Use ' Overwrite format' option while formatting the microSD.
  4. Copy the files from the temporary folder back onto the microSD.
  5. Replace and lock the microSD back on the module.
In case the sounds don't start working again, it maybe that the sounds files themselves are possibly corrupted. Please copy the original sound files onto the microSD. If using factory default sounds, please contact us and we will be happy to provide the original sounds again. In the rare event, it's still not fixed and the module is under warranty, it may need repair/replacement. Regardless of warranty, please contact us to see if any more troubleshooting needs to be done in your unique case to fix the issue.


How do I find out the polarity of a LED?

Scenario 1: Included LEDs - LocoFi comes included with some spare LEDs with leads. There's two ways to identify the polarity (see picture below)
1. The longer lead is positive (anode).
2. If viewed from top, the flatter side is negative (cathode).
Scenario 2: Pre-wired LEDs - If your loco comes pre-wired with LEDs, connect a 3V battery (a 3V coin cell or 2 AA or AAA in series), (see picture below) across the LED terminal wires briefly. If it lights up, the battery + is the anode. If it doesn't light up, it's the cathode. In the latter case, try reversing the battery polarity to double check if it indeed lights up and is not a result of poor connections. NOTE: Please note that the LED terminal wires have been desoldered from the light board / DCC ready board and not part of any other circuit. You don't need to take out the LEDs themselves from their sockets.

How do I isolate the motor?

Let's start by answering a few questions. What is motor isolation?
DC powered locos get their power directly from the track to the motor. The locomotive speed is controlled by varying the voltage/current on the track. This is evident in the brigtness of the ligts that changes when the speed varies. Motor isolation is essentially cutting off the power to motor going from the tracks. Why is it important?
When we install LocoFi™ decoder module, we are handing over the motor control to it. The decoder module will in turn get the power from the tracks / rails and the motor will be programatically controlled by the microcontroller unit present on the baord. This opens up a whole set of possibilities the way you can make your locomotive run. How do I do it?
There's many ways do it depending on the wiring inside the locomotive. First step is to find out how the current is flowing all the way from right track to left track passing through the motor. Second step is to determine which point the power to the motor be cut off. This may involve some out of the box thinking. It must be done in a manner so that the track power can susequently be easily fed into the decoder and the motor output wires from the decoder easily feed into the motor. While there may be patterns around doing it for each locomotive type manufactured in a particular era, it is next to impossible to document all the various types. We strive to produce video content demonstrating the same as and when possible. Please check out videos section to see how this is done in some most pupular types e.g. the old blue box Athearn, Tyco, etc. Also, please check back regularly or subscribe to our YouTube channel to get periodic updates as and when new content is published. PRECAUTIONS: Once motor isolation is done, please ensure by double checking that there is no power whatsoever being fed to the motor directly from the tracks. Otherwise, it may result in shorting the circuitry of the decoder and render it unusable. This is not covered under warranty. One way to check this is to do the continuity test with your multimeter all the while turning the trucks around in all directions (up, down, right and left) to ensure that all paths are open. If in doubt, please do not hesitate to contact us at any time during installation. We will do our best to help you out.

LocoFi™ Technology

How is LocoFi™ different from DCC?

LocoFi™ and DCC are completely different technologies as explained below: 1. Power: DCC equipped locomotives run on DCC powered tracks only. LocoFi™ equipped locomotives can run on
a. DC powered tracks (9V – 24V “clean” DC).
b. DCC powered tracks.
c. Battery power whether onboard (dead rail) or powering the track. LocoFi™, using what today’s latest technology allows us to do, is designed from the ground up to fit into your world, instead of offering another “technology solution” which comes with its own set of limitations that you have to work around or eventually compromise with. 2. Control mechanism: DCC equipped locomotives can be controlled by proprietary DCC controllers only. Some DCC manufacturers are, finally, offering smartphone apps to control their locomotives. However, that still requires the purchase of “command station” at least, and the wiring to go along with all of that to begin with. LocoFi™ equipped locomotives on the other hand are controlled by the controller that you already have, i.e. your smartphone, using the LocoFi™ app available for download on Android play store. iPhone app is on the roadmap. Again, one of the key driving principles behind LocoFi™ is to fit into your current technology world, by leveraging the existing hardware and computational power already ubiquitous in all of our lives, instead of offering another "technology solution" that is not agile enough to evolve with the changing technological landscape. 3. Communication mechanism to exercise Control: DCC equipped locomotives use a very specific, but standard and openly available protocol. This protocol is quite similar to a Morse code mapping of pulses of current. These pulses of current are analogous to 0s and 1s used in micro-computing, and hence the “digital” in DCC. LocoFi™ equipped locomotives use WiFi as the radio wireless local area networking standards to control locomotives. WiFi powers and supports many key components of today's technological landscape, including the internet - be it at home, work or club. By using WiFi as the key communication protocol, LocoFi™ is able to offer a mature and robust technology platform, while weaving into your existing technology infrastructure.

I do not have a smart phone. Can I use another controller? If so, what type?

With LocoFi™, smartphone app is the controller. The SmartThrottle™ as it's called is unlike any other throttle app you may have used before. With latest features like haptic controls, you just notch up and down without having to look at your phone (unless of course you want to see the speedometer :-) to keep a check on speed). The slider on the screen will vibrate for each notch up/down. You can always turn this setting on or off. LocoFi™ is an ecosystem that consists of:
a. LocoFi™ decoders with powerful hardware and firmware onboard that you install in your HO locomotive, and
b. LocoFi™ app that you run on your smartphone to control the locomotive A smartphone is integral to how LocoFi™ enables wireless control and is the only controller you will ever need. Moreover, LocoFi™ app is available for free download on Google Play Store. That makes millions of devices running Android as potential candidates for a controller.

Why WiFi (and not Bluetooth)?

The decision about using WiFi vs Bluetooth for communication was the first in the early design phases of LocoFi™. In fact, Bluetooth solutions were already available while we were still working on WiFi based LocoFi™.

  1. WiFi and Bluetooth are two wireless technologies that both operate on the 2.4GHz spectrum but the underlying protocol is very different.
  2. Bluetooth was invented specifically for exchanging data over short distances while WiFi was intended as a replacement for wired LAN (Local Area Network or Ethernet).
  3. Bluetooth is meant for exchanging small amounts of data only.
  4. Bluetooth speeds are much slower than WiFi. Think video transfer (Bluetooth can't support it).
  5. Since WiFi is a wireless extension of the internet, it seamlessly ties into IoT. Think about cloud and the ability to run your trains on a remote layout (even across the world) or stream your cab video to the world.
  6. Only WiFi can handle a large network (think internet) of locos very easily (though you can run direct WiFi too that feels like Bluetooth but with much higher speeds).
Not to say that Bluetooth is necessarily bad but it may be rather beneficial in some small use cases while WiFi will cover those and many other usecases as well. Bluetooth is especially useful for example in your car or your headset where WiFi will just not make sense. While there is plenty of information available on the topic of "WiFi vs Bluetooth", we tried to present you the highlights of it and the reason why WiFi is better suited over Bluetooth for model railroading operations and the technology of the future.

How does LocoFi™ work?

Simply install the LocoFi™ module in your locomotive and control it with your smartphone or tablet as a throttle.

What do I need for the set up?

  1. You will need to solder 7 wires (or get them done) to install the LocoFi™ module (detailed instructions and many install videos provided). We are always available via e-mail for any further help.
  2. You will need power for your locomotive, (clean NOT pulsed) DC, DCC track power or battery.
  3. (Optional) An access point (or home router) if you want to set up a network of locomotives or need extended range (internet connection not required). For a single loco to be managed from one device, you can go direct WiFi i.e. straight from your smartphone to your locomotive (no router needed). In case you don't have one, most can be purchased for less than $50.
  4. Your smartphone or tablet as a throttle. Again, in case you don't have one, most Android devices can be purchased for less than $100.
  5. Internet connection (cellular or WiFi) on your smartphone or tablet to only download the app (not to run the trains).

Can I use LocoFi™ (DDLLHA) for any other scale but HO?

Let's look at a LocoFi™ module as a device with certain capabilities (please check out the technical specs). Then look at your requirements. If you find a LocoFi™ module model number that matches your requirements, then it's good fit. We currently offer only one model (DDLLHA) which satisfies requirements for most HO scale diesel locomotives or in other words, is optimized for HO scale diesel locomotives. This is not to say it fits all HO scale locomotives or it won't be a good fit for other scale locomotives. As we release more optimized versions for other scales, they will have their own model numbers or product ids. All you need to do is look at your requirements and see if any of the available product model satifies them. It's that simple. Also note that barring things like dimensions, current rating, sound output volume, etc., all LocoFi™ products will still work on the same underlying technology with a single application controller app. You may as well be operating a G scale and an HO scale loco running on two different layouts at the same time as long as they are added to the same network.

Can I use battery to power LocoFi™?

Yes. Absolutely. Since the LocoFi™ module can be powered by DC, a battery qualifies as a very good source of DC. Please check out our video of LocoFi™ equipped locomotive running on a track powered by a 9V battery (or you can just have deadrail and feed the power from the battery directly to the module) or even a 2S LiPo (for DDLLHB only).

Can I run deadrail with onboard battery power?

Yes. Absolutely. See the FAQ 'Can I use battery to power LocoFi™?'. While we do not sell batteries (at least not yet), if you have a battery pack rated for anywhere between 9V - 24V powering the module directly, the LocoFi™ module will perform flawlessly without even any concerns for dirty track.

Why are LocoFi™ NMRA color coded wires not DCC compatible?

DCC was invented as a standard for compatibility among DCC equipment manufacturers. LocoFi™ is NOT DCC. DCC ready boards are just that, "DCC Ready" only. It's a clever way to let a locomotive run on DC when the DCC decoder isn't installed. To make LEDs functional on DC, we need resistors and that is pretty much the DCC ready light board does. That means the LED resistors can't be onboard the DCC decoder to make in plug'n'play or you would be desoldering the SMD resistors from the light board. In an ideal world, an 8 pin connector would be just that, an "8-pin connector". You plug in anything into it, be it a DCC decoder or a LocoFi™ module. Alas, with pretty much only DCC around until now, the choice for model locomotive manufacturers was obvious. That is, to design a DCC ready board in a way that runs on DC power as well. The 8 color coding scheme only specifies "common". It's the DCC standard that specifies that "common blue" should be positive. How does it impact LocoFi™? Well, not much in a way. The LEDs are diodes meaning they conduct electricity in one direction only. Hence, all we need to do it feed the blue wire on the LocoFi™ module to negative side of the LED instead of the positive. Worst case (opposite polarity), the LED won't light up. Please note that a module is complete in itself by having resistors onboard or else you need external circuitry to light your LEDs which in the case of DCC is provided by locomotive manufacturers. Still confused? Questions? Please feel free to Contact Us.

Why can't LocoFi™ modules plug into the 8 pin connectors on the DCC ready boards?

LocoFi™ modules can operate on voltage as low as 7V (for DDLLHB) and as high as 24V. That's a lot of flexibility. Much more types of power supplies to choose from. Sometimes, no standards is the best standard. To make LocoFi™ modules compatible with DCC ready boards, we'll be giving up this flexibility to "run anywhere". We'll have to get the onboard resistors out and for those folks with DC only locomotives who have been waiting for this revolutionary technology to arrive would be soldering the resistors as well, not to mention that they won't be able to use the variety of voltages to run on or risk burning out the LEDs. Other than that, switching around the comomn blue to positive isn't a big deal. We just don't want to give up the power we want to give to our users. Simplicity and flexibility! Please note that we don't provide the 8 pin connectors or else it may be mistaken for DCC plug compatibility and risk destroying the LocoFi™ module. We do hope that in future, model locomotive manufacturers will provide more generic 8 pin adapters that can take in "any" module.

© 2017-2018 by WiFi Model Railroad LLC