An Egg?

Mike here. This post is going to be of limited interest to those who are not fascinated by gadgets and gizmos. I was describing a project I’m working on to my buddy Pat, and he said, “I’d love to look over your shoulder when you build that,” so I’m going to document that in a series of postings here.

I sometimes describe myself as a “recovering engineer.” I don’t have an actual engineering degree, but my past life involved a lot of turning ideas into functioning devices and systems, so I use the term as the most concise description of my old job. As it is with many recovering addicts, I have periodic relapses. Fortunately, these relapses often result in something useful, or fun, or both, so my wife and colleagues tolerate them. It’s kind of like the old joke about the guy who tells his friend, “You think you got problems? My wife thinks she’s a chicken!” “A chicken! Have you taken her to see a psychiatrist?” “I would, but… hey, free eggs!” I’ve built a gizmo that monitors the carbonation process on a brite tank, that has a spunding function as well. A gizmo to control a peristaltic pump driven by a stepper motor, for gentle unattended yeast harvesting from conical tanks. A gizmo to stop me from overflowing my HLT at home, that also allows me to add specified amounts of water automatically. Also a bunch of half-realized whimsical thingies that we hope will eventually appear in the brewery.

So, the current thing I’m working on is an automated water treatment dosing system, to add metered amounts of salts and acids to the brewing liquor as it flows into the mash tun during mash-in and sparging. The idea is to have more uniform dispersal of these things for a more homogenous mash. (I know this is a less-than-huge issue on a damn 5 bbl brewhouse, but humor me.) It’ll have solutions of the most common additions (for me that’s gypsum, calcium chloride, and phosphoric acid,) plus one more for things that are called for less frequently, like baking soda, in small reservoirs, and feed them in periodic measured doses via wee peristaltic pumps as it tracks the flow of liquor. This will be controlled by an Arduino microcontroller, with a pushbutton programming interface that will hopefully be easier to navigate than that damn clock radio of ours.

I have pretty much all of the physical components, so I’ll be starting the build in the next few days, but today I’m going to upload the code I’ve written to a test module and see how that looks.

This is just the startup sequence screen. I forgot to add the water treatment three times running at home, years ago, and wrote a note to myself on the wall in Sharpie, saying “Add the salts, dumbass!”

The interface has a button to step through the selections, and one to increment. Xtra is for the ‘salt to be named later, and VolT is target liquor volume in gallons. VolC is a readout of current volume, and GPM is GPM.

Here’s the run screen, showing entered dosages and current progress. I wrote a janky first draft of the code quite a while ago, and have come back to it recently. As always, what I thought were adequate and clear rems are in fact sparse and cryptic. I found quite a few shortcomings in the program flow as written, so I’ll be wrangling that for a bit, as well as building and debugging a calibration/diagnostic mode so the thing can actually be reliably used in the brewery. It’s not an ‘egg’ yet, but it will be, maybe a dozen!