Saturday, May 30, 2020

Day 113, 114, 115 - More Sensors

Thursday (113) - It warmed up to 80°F today so I really didn’t feel like doing much outside. I finished another D1 Mini and attached it to Home Assistant. This board is for the bedroom and has a temperature sensor, a relay to control the dressing table light, and a small OLED display to show the room temperature and, eventually, the outside temperature. I’m still searching for a good location to measure the outside temperature. I’m also still trying to figure out how to “package” this so the display would be visible but most of the rest would be protected in some sort of plastic box. Right now, it is next to the printer in the space where the original picture tube TV was located and the OLED display is simply sitting in a plastic box along with the breadboard and relay board. It’s a real mess right now so no picture… There are still a lot of available inputs for other sensors or switches.

So far, I have four D1 Mini microprocessors and one EPS-32S processor configured. For the storage bay, I'm currently setting up a NodeMCU which is the larger version of the D1 Mini. Same processor but different packaging. This one will be going into one of the smaller storage bays and will probably be the one with the outside temperature sensor.

The freezer finally got down to 10°F today. It took 36 hours to recover from our shopping trip. I’m thinking of picking up a small 12VDC/110VAC compressor freezer that will live in one of the storage bays. Much more efficient and will freeze stuff faster. A small freezer like this was an option on this coach so there is a location that is already wired.

We went back to the Pendleton factory store again and I picked up a nice wool shirt for ~30% off and a t-shirt for ~50% off. I should probably throw out a t-shirt but the old ragged ones are nice to have when working on the coach. At least that’s my story.

Friday (114) - Today’s forecast is for 91°F. Needless to say, it’ll be spent indoors. The NodeMCU I started playing with yesterday is a bit more challenging to program. Just a bit. The I/O port numbers silk-screened on the board don’t match internal GPIO ports. With the D1 Mini, they don’t either but within the configuration, you can simply use what’s on the label. I found an image on the Internet for the NodeMCU board and printed it out. So far it has one DB18B20 temperature sensor, one DHT11 temperature/humidity sensor, an OLED display (to display the sensor measurements), and a relay board. The relay board it to provide power for the RGB awning lights. I may replace the relay some time with MOSFETs and control the three LED colors myself.

For testing (until I can find a good plastic box), I have this built on a hobby board in the storage bay with the outdoor TV. I need to think of a good location for the outside air temperature sensor. Right behind this storage bay is an open-air space that has the fuel tank forward and the propane tank across. Having the sensor mounted there may be good though it may be warmer than ambient if the generator is running or if we are parked on hot asphalt. There isn’t much airflow down there.

Saturday (115) - In the bedroom, there was an old analog to digital conversion box taped to the cabinet next to the TV. This was for the original tube-style TV that used to be there and isn't needed anymore. So I decided to repurpose the case. I removed the original circuit boards and installed the D1 Mini, the relay shield, and the OLED display. Right now, I'm waiting for the glue to dry that is holding the little OLED display to the front panel. Note that there is plenty of room for some other components. I'm thinking of adding a relay to sort of bypass the existing thermostat controlling the rear furnace. Since I have room temperature, I can easily make a thermostat that I can fully configure. The furnace is controlled by the rear A/C with a remote sensor also connected to the rear A/C. The rear A/C is networked to the front A/C which is connected to the thermostat. Sometimes it all doesn't work very well and the room gets too hot when the furnace doesn't shut off. But that's a future project. It depends on how often it doesn't work.

I think it turned out okay. The OLED display shows the time, bedroom temperature, and the outside temperature. The main advantage of the box is that it’s opaque. There are multiple LEDs on the boards that are on all the time.  They show that they are working.

Yesterday, the Alaska governor extended the mandatory 14-day quarantine for anyone arriving into Alaska from out-of-state. If you have proof of a negative test result that is less than 72 hours old, you don’t need to quarantine. The challenge is finding somewhere that will test without a referral. 


  1. Wow, you have been working hard on your automation project! We have an indoor/outdoor mini-weather monitor, and the challenge is finding the right place for the outdoor sensor. In the winter, we keep it in the wet bay, even though we have an automatic furnace function that keeps it warm below 40 degrees. But the rest of the year, it is on top of one of the tires, under the strap that holds our tire covers on. We just have to pick a tire that isn't in direct sun AM or PM. 😊 Definitely a first world problem...

    1. I really like projects like this. I’ve been thinking of doing some sort of home automation project but more on the data collection than automation. But some things on the RV don’t work as well as they could such as the thermostat. We also have warm air into the wet bay but there isn’t any temperature control. There is a 12VDC electric heater right in the wet bay with a thermostat but the heating element must be burned out. Our wireless sensor for our indoor/outdoor thermometer is in the bay with the propane tank. I.e. a bay without a floor.

      I’m thinking of using a combination of outdoor temperature, indoor temperature, and power availability (30amp, 50amp generator, or none) to automate the selection of heat pump or propane furnace. Dometic claims that there is a temperature sensor on the heat pump to make that decision but if there is, it doesn’t work very well. The one automation that I do have working all the time is for the step lights to come on 30 min before sunset and turn off at 10pm. It seemed like a harmless thing to automate. And the automations can be turned off or enabled with the web portal. I can also access the sensors and automations from the Internet if we are out and about. That seems potentially useful.

      The next “major” task is to figure out how to collect data from the Victron battery monitor.

  2. All very useful enhancements. Sounds like you'll be busy for the foreseeable future! 😁

    1. It's something to do during these days of too many things closed…