The Problem

Yesterday morning, I had discovered that my automatic feeder on my aquarium had dumped its entire hopper in the aquarium (not a big deal, it was almost empty), and was unable to retract the hopper to the original position. I initiated a manual feed via a button on the back, and the hopper would just spin and never return to initial start position.

I initially thought that the gear mechanism had just gotten misaligned or stuck, I disassembled the feeder and reset the gears so that everything was in the correct initial state. Upon testing I ended up with the same result. This now meant that I had to figure out how the feeder knows when to retract the hopper back to the initial state at the end of the feed cycle.

The Dunning-Kruger Effect is often used to explain overconfidence, but I don’t think we talk enough about its opposite effect.

As someone who’s spent years as a “jack of many trades,” I’ve found myself well past the “Peak of Mt. Stupid” in several areas, now sitting somewhere between the “Valley of Despair” and the “Slope of Enlightenment.” With experience comes perspective, and with perspective comes the uncomfortable awareness of just how much there is to learn.

Background

I have a 135gal saltwater aquarium in my office full of coral and several fish. The system is fairly automated, it is controlled by a commercially available aquarium controller running custom rules that I have programmed into it to control heaters, supplement dosing, pumps, UV sterilizer, Ozone reactor, etc. I’ll probably make a post at some point in the future explaining the setup.

The supplement dosing is the trickiest part of the whole system, it requires constant water parameter testing to ensure that the correct amount of supplements are being dosed, and I also have to ensure that I don’t run out of the supplements. As I get busy with life, kids, work, etc, inevitably I forget to check the containers of supplements and the system doses nothing to the tank for days or weeks until I remember to check them.

Cisco ASA 5510

I need to brush up on my networking skills, so I thought that I would dig out the old hardware that I purchased back when I initially got my CCNA certification. I figured I’d first start with this ASA Firewall since many job listing I have been seeing for Network Engineer jobs have mentioned firewall configuration. I purchased this ASA in probably 2017 or 2018 and it was past end of life then (foreshadowing…..).

Populated Board

I populated the board with the Arduino board and the pin headers. Assembly was very straight forward. I added pin headers for the GND and +12V lines for testing purposes, in the future I’ll either add a barrel connector or just wire the power supply directly to it.

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The Test

I used SimHub top program the Arduino via USB, connected the fans to the Right and Left fan channels and used a barrel connector that has screw terminals that was able to just slide over the GND/+12V pins.