We are bringing back the blinking lights!
Last time, we spiraled lights up around the north end and placed lights around the inside of the south end. This time, we will be leaving the south end lit only by the lights in the pool and the north end will have random blinking lights.
The above image is very important to using and understanding the north end lights. Inside of the gray box is an Arduino that is programmed to randomly turn on and off the lights (code here). The physical box is set up to receive power from two locations. First, the Ethernet cable that plugs into the board supplies power to the Arduino. The wires are labeled with scotch tape. V+ is the positive and GND is the negative. It runs on about 5V. The main power cable attaches to the bundle of green wires and the single back wire. [Ed note: You'll have to figure out which is positive and negative. I'm just a lowly CS student] This cable should run on 120V.
With all of this ready to go, we should have all of the lights working by next week.
Through a series of unfortunate events, we are shutting down the fountain a bit earlier than usual. But we’re getting ahead of our selves. Let’s start from the beginning.
On Thursday, Madison had a very blustery and cold day. There was snow and wind, and everyone was generally unhappy with the whole situation. Someone was particularly unhappy with the running of the fountain. Apparently, the wind was blowing water from the fountain onto the sidewalk and into people’s faces. To alleviate the problem, Dustin was asked to shut down the fountain. To do so, he remote connected into the server and shutdown the fountain via software. After shutting the fountain down and then leaving to go to class, Dustin saw the fountain was still running. He ran to class and used RDP on his phone to try to shut down the fountain. After class, the fountain was still running so Dustin had to open the manhole cover and manually shutdown the pumps. (Note: the failure to shut down the fountain may have been due to a crashed cRIO).
With the pump off, the water stopped flowing and everybody was happy. The water level sensor had other ideas. It seems that after banging on the water level sensor, instead of being stuck off, it was then stuck on! When the water level sensor is tripping, it tells the pool to drain. Because the sensor was stuck on and the pump was off, the south end pool drained completely with the lights still on. When Dustin saw this, he realized that the pool needed to be filled so he turned on the pumps. Well, hot lights + cold water = explosions everywhere! The four lights that we replaced and got working exploded and shot glass everywhere. Needless to say, there was a bit of panic involved.
One of the things that we had been warned about was that nobody knew where the glass lenses for the lights came from. We were afraid that the fountain lights would not be operational during the winter. However, it was just our luck to find a box of replacement lens. We needed four; guess how many were in the box. Four. You really can’t make this stuff up.
On Saturday, Dustin and his brother Taylor, went out to fix the fountain. They cleaned up the glass, replaced the lenses, and acid washed the water level sensor. With the sensor cleaned and functioning properly, most of the lights resumed working. Only one of the four blub sockets was damaged beyond current repair. We will resume repair in the spring. After completion, the fountain resumed normal activity with three lights on.
When one thinks of engineering, complex plans and well thought out solutions come to mind. This is true for many aspects of engineering, but when it comes to the real world, you’ll find that the solutions are not a elegant as you would hope. We had a problem for two and one half months where the lights in the south end pool were non-functional. We knew the there were shorts in the wires, but we didn’t have the time or expertise to figure out what was going on. This Tuesday, Dustin and Alex tried to test the water level sensor power box to see if they could short out the input to trick the lights and have them turn on. They found that the sensor was giving the same results when the pool was full and empty. Then they did the next logical thing, bang the water sensor with a wrench! After making a few loud clangs, the lights came on. There was probably something stuck inside the senor, but we’ll never know for sure.
Moral of the story: When in doubt, hit the pipes with a wrench. That has fixed a lot more problems with the fountain than we’d like to admit.
After “fixing” the water level senor, the remainder of the meeting was dedicated to preparing the holiday lights. We were able to find the controller box for the lights, but it was in a big mess of cables. It took us a bit of time before we were able to finally untangle all of the lights. After opening the lights control box, we found the homebrew Arduino setup. We ripped the chip out with some make shift wire and will begin programming it next week.
We continue to test the fountain and locate points of failure. The lights in the south pool are still off. We are not sure if the water level sensor is not tripping causing the pool lights to activate or if the water in the lights is causing a short for all of them. We tried flipping the breaker to see if any of the lights worked but none did. To help clarify how things are working, we will be measuring the power in the water level sensor. If we can trick the system into turning on the lights when the pool is empty, we might be able to see if the water is causing a short.
In other news, a student documentary is being produced about Enlight. Katie will be filming Enlight members over the next two meetings. It will be interesting to see how the film turns out.
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