Saturday, May 23, 2020

Day 107, 108 - A Few More Boards

Friday (107) - It really does take an RV freezer a long time to get cold. Ignore the steep curve as that was moving the sensor from room temperature to being zip-tied to a shelf (though not touching the shelf). The little blips are from opening the freezer door. Each door opening was just to take something in/out. Maybe 10sec or so.

Saturday (108) - I built up a board for the wet bay. This is the location for the freshwater fill as well as dumping the holding tanks. I added two temperature sensors and placed one on the holding tank outlet and the second one on the freshwater tank about 5" from the bottom. It is taped up for now since I am testing the location to see if I get reliable WiFi down here since it is under the tile floor in the hallway. The signal strength is -62db which is actually better than the other one mounted in the refrigerator plastic facia. Not what I expected. I soldered this board and plan on finding some sort of plastic box. For testing, I'm just powering it through the micro-USB port but next week I'll install a buck convertor and power it from the 12VDC light.

So, the Gorilla tape is back for a couple of days. Arriving from Amazon are some PC board screw connectors for heavier gauge wiring and some more Anderson Powerpole connectors. I've sort of "standardized" on them for my 12VDC additions and used up most of my supply.

And just to see if/how it works, I built up another D1 Mini which drives a relay through an opto-isolator.  Once I could simply turn the relay on and off, I am trying out automation within Home Assistant. At sunset, it turns on the relay and turns it off at sunset plus 90 minutes (for the test, I’m doing 30 minutes). Local sunset is determined by your location within the software. The Raspberry Pi does not have a GPS so the location needs to be manually set. Another option instead of a relay is a FET but these were back-ordered. They should be delivered at home by the time I get there. The advantage of the FET is the brightness can be controlled using PWM (pulse width modulation). But for now, I'll try simply on/off. If it works, I’m going to set it up on the step light.

This really is fun (for me)!

Update - Both parts of the automation worked!


  1. Glad you’re finding such enjoyment from these automation devices!

    1. More information is a good thing (in my opinion). I’m thinking of adding current monitoring to both legs of the shore power connection as well. Just because I’m curious…