BIRTHA - Base Interface RV/Trailer Home Automation

The Plan

We need reliable cellular data, so an omni-directional and rotatable Yagi antenna on a mast will be implemented. A cellular repeater/amplifier will feed the signal from the roof to a directional antenna inside the RV.

The RV will have its own wifi via an on-board cellular modem capable of multiple carriers.

A simple website will be hosted from the RV wifi with a Pi 3, and from that site, some home automation software will be exposed.

Add physical interfaces via relay boards to the slide switches and nearby lights. Leave the existing switches in place for the lights, but have them trigger the automation software instead. This will essentially turn them into 3 way switches with the hidden switch controlled by the automation software. If the switches are already 3 way capable, then wire them as such. The relays are SPDT so this will work, and this way everything would still work even if the automation was off.

Tap into the analog signals feeding the black, grey, and fresh water tanks.

Add an RS-485 interface and tap into the communication between the wall panel and the house inverter to get battery and line status. Later, perhaps actually spoof traffic and trigger things like starting the generator via the AGS system.

Control over the AV systems would be nice as well, and the RV came pre-wired with an HDMI over ethernet 4x4 multiplexer. I'll need to emit IR to control it and the other home entertainment stuff.

Figure out where to put a projector and screen as we need the space currently occupied by the living area flat screen for other stuff. I'm partial to using the front power window shade as the projector screen currently with a short throw projector hidden either in the dash or in the upper cabinets.

Lastly, integrate with Alexa, Google Home, or CMUSpinx for voice control over the simple stuff.

This is going to be fun. :)

Project Logs

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Water heater servo
MasterOfNull • 03/07/2020 at 03:16 • 0 comments

Printed a new gear for my water heater servo so it is self centering now.
Still have yet to write the MQTT or PID loop bits for it.
Progress.
MasterOfNull • 03/05/2020 at 09:00 • 0 comments

I am getting back to this!

I have the sum of most of what I want to do here sorted, some more parts modeled and printed, the processor/electronic bits chosen, and most of everything in hand. So here is where some of this is now at...

OpenHAB will be running the show on a spare Pi 3B+ I had. It has been loaded and put on the network. Then it got taken off and is waiting for some small project boxes to arrive so I mount it and run it off of 12v.

I also decided to fix an issue we have been having with the on-demand hot water heater we have. It is very sensitive to the ambient temperature and varying water pressure, but it does have a manual adjustment which allows you to alter the ratio of gas/heat to flowing water. It is relatively hard to turn, so I modeled a mount/3:1 gear drive for a servo to spin this bit and printed it in nylon. I also have a couple temperature sensors and a flow meter now, but I still need to work on the software/PID stuff for it.

Wires were run to put wired ethernet midship where the Pi will live, and I2C leaders were run to where the relay board and vent controls will end up.

Yes, I'm automating opening/closing the roof air conditioning vents after having to do it manually, twice a day. We run the forward air with all the front vents closed to cool the rear bedroom every night, which means opening and closing all the vents. I modeled a little mount for a 9g servo for this and ran wires in the air ducts the length of the RV for this. I may still end up not directly interfacing with the Pi at all and making everything NodeMCU boards just for simplicity.

The remainder of the controls do need to go further, but those will flow via MQTT to NodeMCU based purpose built endpoints for things like the antenna, water heater, lighting PWM, etc. I decided to scrap the idea of using NRF modules and RFShowControl/DMX-512 It's just simpler to switch everything to run via wifi/MQTT.

For lights, the endpoint NodeMCU will still monitor the existing wall switches for state changes, and then directly trigger the lights locally. This should still let me turn the lights on/off... without a network connection. :) The status will be forwarded back to OpenHAB so I can also still control it that way.

I also toyed with the idea of running the Pi wifi in master mode and having a private MQTT network. I really like this idea as our wifi can be somewhat saturated and this would let me run the automation stuff on a completely different wifi channel. Forum posts seem to discourage this, but I'm not sure if their reasoning applies to how I am doing things yet. Perhaps.

Some of these parts may be large enough to warrant having their own project. That will help keep things organized as well, so I'll probably end up doing that soon.
Necessity is the mother.
MasterOfNull • 02/24/2019 at 03:58 • 0 comments

After a stint which bordered most of the US, we are parked now.

Access to an ok shop (hand tools at least) and materials is now at hand, but there is no longer the immediate need for most of what I was trying to do here. Focus has shifted.

The pneumatic antenna mast died during the trip with a failure of the silicone tube which was driving it. It has since been re-designed as a screw drive, and a new rotation/extension mechanism designed/fabricated. That is waiting to be installed.

The existing HDMI switch lost a channel and I'll need to get a new one. They are surprisingly expensive for the RJ-45 output version. I moved one plug and that is stalled.

We have both Amazon and Google products in the RV. Right now I haven't bothered to make them play nice together, so voice control is stalled there.

The relay board won't quite cover all the functions I need it to. I've been looking at alternatives.

That is about it. As excess time, or increased need presents itself, I will continue here.
Systems
MasterOfNull • 04/26/2018 at 07:10 • 0 comments

So here are the onboard systems I need to interface with.

From research, the Magnum Energy inverters, Automatic Generator Start, and user panel all use RS-485 to talk to each other and the read-only part of this at least has been decoded. As I can set the system to start the generator itself (as that is what it's for), tackling this from the read-only perspective should work for now.

This panel looks to be just a couple SPDT switches for the slides and some sort of analog interface for the tank/propane levels. I should be able to simply wire across the slide switches and tap into the analog signals directly. I don't know the levels involved yet for the analog.

The single lights controls. The trim ring snaps off with a pull, but they are screwed in to the paneling with an S2 drive. I only had a Phillips with me so I'm still not sure if these are SPDT or SPST switches thus far. There is at least one SPDT switch as the main living area is already 3 way, with one switch at the RV entry and the other in the middle, so I'm hopeful.

Here is the existing centralized AV HDMI over ethernet switch. I wasn't able to find anyone who has built a library for sending IR to this device yet, and I don't have a remote for it. AV switching will have to wait a bit.

All the systems thus far are centrally located and within 2 feet of each other. I should be able to control all the simple stuff from this one location with a relay board. The same mirco I task with the analog bits will also be intercepting the RS-485 for the house battery status.

As for the more remote things...

There are also 4 TV's, but three of them are the same brand and so use the same IR codes. I'll need at least 3 IR blasters. to cover them over 3 isolated channels. Annoying.

The switch panel in the entryway covers the awnings, more lights, and steps and is far enough away from the other panel that I plan on using an RS-485 masters/slave serial link to it with an Arduino driving a separate relay board.

Lastly I'll need to control the mast rotation and extension. That's all the way at the back of the RV and so about 10 feet from the main board. I haven't decided if I want to make that an RS-485 link or just run the wires yet. I have power there so RS-485 may make sense.