How to Build the eRVin Hardware
As described on the home page of this site, eRVin is a micro-controller that interfaces to an RV-C based Firefly RV control system that is present on many late model RV’s. eRVin provides the ability to remotely (from anywhere there is internet) control the RV systems via an “app” or web page, and also adds additional support for devices like the Amazon Echo (Alexa) to enable voice control of lights and other subsystems. This post describes how to put together the micro-controller hardware needed to interface with the Firefly/RV-C system. Once you have completed the hardware build, proceed to Installing an eRVin Software Image.
It’s pretty easy and inexpensive to put together the hardware that can run an eRVin image. If you have a Tiffin product, the same exact hardware will also run a CoachProxy image. If you are comfortable plugging two circuit boards together, mounting them in a case and hooking up 4 wires (with a small screwdriver, no soldering), crimping on a connector (no special tools needed) and then plugging the system into the Firefly G5 or G6 panel on your coach, then this project is something you can do.
Cost will be between $90-$150 depending on where and what versions of the parts you purchase. The lower end of the price range is if you source the parts from the cheapest sources and assemble it yourself. The high end of the price range is for the assembled Copperhill version (no longer available as of 2022). Once you have the hardware built you can download and flash an eRVin or CoachProxy image and get your coach automated!
Note: Many have asked if I would sell them a completed system. Currently I am not able to do that due to time and other constraints. Also as of circa 2022 parts are difficult to obtain. The basic assembly in my view is trivial, however a few have had trouble with the cable and special connector – if I get enough demand I may be persuaded to pre-fabricate a cable assembly that you can purchase. TBD.
eRVin should work on any brand/model RV that uses a Firefly panel like the G5 or G6 (and perhaps others). This includes Fleetwood (and all other REV variants), Thor, Winnebago and probably many others. However, currently I do not have customized images for any coaches other than Entegra (and Tiffin is supported via the CoachProxy image). The customized changes required are limited mostly to things like the names and “instances” of lights, shades and other subsystems, so if you have the incentive to do a little configuration work, I will be describing further along on how to do some of these basic reconfiguration tasks yourself.
Note: As of mid-2022 I will no longer be producing customized configurations for the various brands/floorplans. This is too time consuming and difficult for me to test. The base configurations will be for a 2017 and newer Entegra 44/45B, more on this later. However, I will be creating more detailed posts on this site regarding how to make the relatively minor changes needed for different floorplans. My hope is anyone who successfully does this will allow their work to be posted here (with credit of course) for use by others.
ENTEGRA – eRVin will theoretically work on any Entegra that has a Firefly G5 or G6 panel and will peacefully coexist with a Vegatouch system, should you have one. That includes all Entegra’s back to at least 2013 and possible older models that have a Firefly panel ( if you have “multiplex lighting” controls you probably have a Firefly panel). At a minimum, eRVin is able to control lighting on all the aforementioned Entegra models. Electric shade control has been tested as far back as 2015 but will probably also work on older units. Other subsystems may also be eventually supported (generator start/stop, slides, awnings, locks, etc.). In addition, performing enhancements to existing subsystems aboard your coach can enable additional features. For example, on a non-Vegatouch Entegra, upgrading your SeeLevel Monitor panel to an RV-C version will enable tank levels to appear on your eRVin dashboard.
TIFFIN – the CoachProxy image supports most Tiffin products up thru 2019 (and maybe a few newer), the CoachProxy Compatibility page has details of the functions available based on year/model Tiffin. CoachProxy documentation can be found here.
NEWMAR – as far as I know Newmar products do not use Firefly for the lighting controls and are not compatible with this project, at least for lighting. There may be other aspects of Newmar however that do use RV-C and would be compatible. Comments and suggestions from Newmar owners are welcome!
OTHER – As mentioned above eRVin will work with any Firefly panel but the specifics will vary between brands/models/floorplans. The changes required do not generally require any coding and most can be done in a drag and drop environment.
Note: as of mid 2022 all versions of the Raspberry Pi are in very short supply as is the PICAN board.
- PICAN2 or PICAN3 CAN board – Provides the interface to your RV-C network and a power supply that runs off 12 volts. This board has proven to be reliable and of high quality. The only source I am aware of currently for this board in the US is Copperhill Tech. It can also be purchased from SKPang in the UK (it may be more readily available there and could actually be cheaper if the exchange rate is favorable). (Note if you will be using a Rasberry Pi3B or 3B+ the PICAN2 is sufficient, but the PICAN3 will also work, if you will be using a Rasberry Pi4B or newer, you must use a PICAN3). Be absolutely sure you purchase the version with the SMPS (Switched Mode Power Supply) option. The SMPS option (the small green daughterboard shown in the photo right) allows the PICAN2 and the Raspberry Pi to receive power simultaneously from the 12 volt Firefly network, so there is only a single 4 wire cable needed. If the SMPS option is not purchased, a separate 5 volt power supply will need to be added to power the Raspberry Pi complicating things needlessly. This board ships with the hardware (8 screws and four 11mm tall standoffs) needed to assemble it to the Raspberry Pi.
- Raspberry Pi – Preferred version is a Rasperry Pi 3B+, but if not available a Raspberry Pi4B is OK, despite it’s somewhat higher power consumption and tendency to get hotter. The Pi’s are available from many sources so shop around.
You can also buy it in an assembled kit from Copperhillthat includes the PICAN (be sure to order the SMPS option which is also referred to as “Extended Input Power Range” option). Raspberry Pi 3B will also work fine for this project, but we don’t suggest using a version older than that. The newer Raspberry Pi4 as mentioned has increased power consumption which could potentially negatively impact the Firefly system, however, in practice I have not yet hear of this being an issue. Note also that the Pi4B requires the PICAN3 board (also here) which has a more robust SMPS power supply.
- Case – A case is required to protect the system. Standard Raspberry Pi cases will not accommodate the PICAN board, so something like the “HighPi” case is needed. When shopping cases be sure you are looking at the correct cases, there are physical differences between the various Raspberry Pi models and RPi3 and RPi4 require different cases! My preferred case is the HighPi case, which comes in versions for both the RPi3B+ and RPi4B. It is also available in a non-see thru version. It has knockouts that when removed accommodate the PICAN connections. It is also easy to assemble and the SD card can be removed without opening the case. The only issue I encountered was that the standoff’s between the Pi and the PICAN ideally needs to be 12mm otherwise the fit is too tight around the PICAN2 connectors. The PICAN2 board comes with 11mm standoffs, so I simply added some small washers to increase the height to 12mm.Copperhill also sells a custom case that works with the PICAN2 however it has several issues. It is very expensive ($26), it tends to break even if you are careful (I have broken 2 out of 2), the case must be opened to hook up the CAN and power wiring and the case must be opened and the Pi extracted to remove the SD card. Every time the case is opened the flexing required weakens the plastic and eventually it will break.
On the other hand if you want to get almost everything from one source, when you order both the assembled RaspberryPi kit and the case from Copperhill, they will install the case for you.
- 3M Mini-Clamp Connector – Qty 1 part # 3M 37104-A165-00E. These are the connectors Firefly/Spyder uses for all of their drop cable connections. Easily crimps with a pair of pliers. Available from many sources, search on the above part number as the best sourcing varies. Digi-Key is (if they have them in stock) offers reasonably priced USPS first class shipping for small quantity lightweight items like this. Only one is required for this project but I suggest ordering extra of these for future use – or – in case you make a wiring mistake. See this post for instructions on crimping these connectors.
- 4 Conductor 20-24 Gauge Drop Cable – Qty ~ 2ft. Ideally you will want to use genuine RV-C drop cable. This is a 2 twisted pair cable (4 wires) with 24 gauge stranded conductors. The official conductor color coding is Red (+12), Black (Gnd), Blue (CAN-L), White (CAN-H). The only reliable source I know of at the moment is Spyder Controls in Canada for $0.50/ft. You may also be able to purchase it from Firefly in Middlebury, IN, but I have had a lot of issues with them lately, so be careful they don’t rip you off. Tell them you want RV-C drop cable. Last time I bought cable from them (circa 2016) it was $0.26/ft. I suggest buying extra for future projects. It is also acceptable to use much more readily available CAT 5 or 6 network cable. CATx cable is 4 pair (8 wires) so just cut off the two unused pairs. Ensure it is stranded (not solid) and between 20 and 24 gauge to be compatible with the 3M Mini Clamp plugs. NEMA2000 (marine) cable is another option, in fact the basic parameters of the RV-C and NEMA2000 CAN are identical. However, the marine cables are very expensive and come with integrated connectors, so unless you can find the raw un-terminated NMEA2000 cable this is not a good option.
Notes and Physical Connectivity Details:
- Check your PICAN2 board and if it has a jumper installed for the termination resistor, remove it. The pre-assembled kits from Copperhill come with this jumper installed by default. If you bought your PICAN2 card standalone, they usually do not have the jumper. Termination resistors are only required at each end of the network trunk cable. Leaving the PICAN2 termination resistor active will cause erratic operation or possibly complete (temporary) failure of your Firefly network.
- The wiring configuration for the connector and cable is shown in more detail in this post.
- If you purchased the Copperhill pre-assembled kit skip to step 4. Otherwise locate the RPi and PICAN2 boards. The PICAN2 comes with 11mm standoffs, attach these to the RPi using the included screws. Note: if you are using the HighPi case we suggest adding some nominally 1mm thick washers between the 11mm standoff and the RPi which will provide a better fit in that case, as shown in the photo above.
- Optional – if you purchased a heat sink kit install it now. When you install the PICAN2 make sure it does not contact the metal heatsinks.
- Position the PICAN2 over the connection header and line it up. Push down gently and evenly. Don’t use extreme force, if it doesn’t want to go evenly make sure all the pins are lined up properly. Install the screws into the standoffs from the top of the PICAN2 board.
- Check if your PICAN2 board has a termination jumper, if so you MUST remove it! See photos in the previous section.
- Fabricate the RV-C cable.
- See this post for how to crimp on the 3M Mini-Clamp connector on one end. Two or three feet of cable should be plenty if you are using the Net Port on the Gx panel. If you want to locate the eRVin device somewhere else, make your cable the appropriate length but avoid exceeding 6′.
- On the other end of the cable, strip off about 1 to 1.5″ of outer sheathing, untwist the four conductors and strip about 1/4″ off the end of each. If you know how to solder, tinning the ends will make the next step easier but it is not necessary.
- Wire the cable to the terminal block on the PICAN2. Back off the screws far enough so they are out of the way while inserting the wires. Follow the color code below.
- CAN L
- Install the assembled unit into a case. Note: some cases may require the SD card be installed before the board is mounted in the case, if so do steps 8-9 first.
- Now proceed to Installing an eRVin Software Image