Wireless Controller and App Developement

[tjsc5f]

Over the past few weeks I've been working on a wireless (bluetooth) controller that uses an Android app as an interface.
What started off as a simple slider to drag around and control a voltage regulator quickly snowballed into a full blown controller with multiple modes, feedback and various (optional) PID controls.
The Software:
Android App developed with MIT App Inventor
3 modes of operation:
1) Pot Still Mode - Boiler, vapor and coolant temp measured with temp probes in thermowells. Boiler ABV and Product/Vapor ABV calculated based on measured temps and atmospheric pressure compensation (pressure measured with phone baro pressure sensor). Vapor rate calculated based on power input and column diameter. Product rate based on power input and boiler ABV.
Boiler power is a sider with a linear power output. This is a big improvement over the "SCR"s with knobs that are super sensitive and only work in the last ~20% of their range. The aux power switch controls a secondary element, on or off only.
Coolant SP (setpoint) is the target for a PID controlled cooling loop. In my case it varies the RPM of a cooling fan, but it could easily be configured to vary coolant flow as well.

Pot.jpg

2) Manual Reflux Mode - Same as Pot Mode, but Reflux control added. In my case, the slider controls a stepper motor that is attached to a gate valve. 0% is fully open, 100% is fully close (100% reflux). The coupler has a worm incorporated that rotates a gear with an indicator on it. This gives a visual representation of valve position, similar to the handle of a ball valve ( vertical = valve close, horizontal = valve open).

ManReflux.jpg

3) Auto Reflux Mode - In addition to above, an ABV SP is added, which assigns a target for a PID loop linked to the head temp/abv. The thumb on the reflux slider is deactivated, but the PID activity is still displayed on the bar.

AutoReflux.jpg

4) Settings - Most of this is self explanatory (set your modes, put your still info in). Est. Losses (W) is a value adjusts the power based calculations and is mostly dependent on how well your still is insulated. The Data Logger option will send all of the info to a Google Sheet if it is activated and you are on wifi. Boiler/Vapor offsets are essentially temp probe calibrations.

Settings.jpg

Controller Firmware developed with Arduino IDE:
I started off using 4th/5th order polynomial equations found on the parent site and here on the forums to calculate the ABV from temperatures, and then luckily stumbled on Edwin Croissant's RGB EParrot project. Using his library to do the conversions cleaned things up a lot and allowed for pressure compensation which is awesome. The temperature offsets were some other features that I added because of the influence of his project.

The Hardware:
ESP32 microcontroller, LSA-H3P90YB solid state voltage regulator, DS18B20 temp sensors, SSR, H-Bridge motor controller, 24V power supply, NEMA 17 stepper motor, TB6600 stepper driver.

At this point everything is bench tested and working. As soon as the crazy hot weather breaks I'll do my first true test run and update.
I am not a programmer or coder - my code is super dirty, inefficient and probably even down right disgusting, but it works. If anyone is interested I'd be more than happy to share the .ino (arduino ide) and .aia (my app inventor) files.