Brewmaster's Buddy

Background

My best friend in town is the brew master (yes, I'm quite lucky). I've got a good thing going and I don't want to shake that up. So naturally, once I learned that some brew masters have died from carbon dioxide (CO2) exposure, I knew I had to do something to keep my good thing going (oh yeah, and also to save the life of one of my best friends 😉).

Digging into the Problem

CO2 is a natural byproduct of brewing, and it is also used to serve the beer from the draught lines. CO2 is a colorless and odorless gas that is naturally present in the atmosphere. If the concentration of CO2 becomes too high, then it will induce drowsiness, and ultimately death, before the victim can even realize what is happening.

To give you an idea of a standard atmospheric concentration, I recorded CO2 levels of about 800 parts per million (ppm) at my desk, while I was working on this project.

Here are the standard tiers of CO2 exposure defined by the USDA:

• 5000ppm (0.5%) - OSHA Permissible Exposure Limit (PEL) and ACGIH Threshold Limit Value (TLV) for 8-hour exposure
• 10000ppm (1.0%) - Typically no effects, possible drowsiness
• 15000ppm (1.5%) - Mild respiratory stimulation for some people
• 30000ppm (3.0%) - Moderate respiratory stimulation, increased heart rate and blood pressure, ACGIH TLV-Short Term
• 40000ppm (4.0%) - Immediately Dangerous to Life or Health (IDLH)
• 50000ppm (5.0%) - Strong respiratory stimulation, dizziness, confusion, headache, shortness of breath
• 80000ppm (8.0%) - Dimmed sight, sweating, tremor, unconsciousness, and possible death

Framing the Solution

As you can see, there are several different levels of concern when working with CO2. Naturally, it follows that you may have a different tolerance for the ambient level of CO2, depending on what you are trying to accomplish.

In a brewery setting, if you are serving beer, then you have NO tolerance for elevated levels of CO2. In this circumstance, any rise in CO2 would likely indicate a leak in the draught lines, which would place all employees and patrons at risk. Alternatively, when beer is actively fermenting it MUST off-gas excess CO2. As such, elevated levels are expected and must be diligently monitored.

Minimally, we need a CO2 sensor capable of detecting CO2 concentrations up to, or above, 5000ppm; the OSHA Permissible Exposure Limit. However, in a brewery setting, we would be better served to have a CO2 sensor capable of measuring the entire spectrum of CO2. Ideally, we would like to have a CO2 sensor capable sensing the entire range identified by the USDA, which would give us the ability to react to the nuance of the activity in the brewery.

Reenvisioning the CO2 Sensor

After a cursory look across the internet, I found several CO2 detectors, but none were capable of reacting to different levels of CO2. However, I did find a CO2 sensor capable of sampling 0 - 50, 000ppm. Beyond 50, 000ppm is almost certainly lethal, so reporting up to this level is sufficient for our objective.

The primary function of any sensor is to observe and report, but that solution doesn't take into account the progress made in the last 75 years of electronics. By adding internet connectivity to a CO2 detector, one can leverage the power of the Internet of Things (IoT) and offer a range of advanced features that a standard CO2 detector without connectivity cannot.

Here are several possibilities and features that can be realized with internet connectivity:

• Remote MonitoringAccess real-time data from anywhere in the world through a web interface or a mobile app. Monitor multiple brewing locations and sensors from a single dashboard.
• Instant Alerts and NotificationsReceive push notifications, emails, or texts when CO2 levels exceed predefined thresholds.
• Data Logging and AnalysisAutomatically log CO2 levels over time for trend analysis and brewing process optimization.
• Integration with Other SystemsOpens up possibility to interact with an orchestration device that could potentially connect with HVAC systems to automatically adjust ventilation based on CO2 levels.
• Firmware UpdatesRemotely update the sensor's firmware to add new features or security patches without physically accessing the device.
• Customizable AlertsCustomize the alert system to include critical information such as exact CO2 levels, time of the alert, and suggested actions.
• Machine Learning Optimization:Apply machine learning algorithms to predict and alert about potential issues before they become critical based on historical data patterns.
• Community Sharing:Participate in collective data projects to improve brewing techniques and safety standards.

By connecting a CO2 detector to the internet, you can transform a simple monitoring tool into a component of a comprehensive brewery management system, allowing for more informed decisions, improved product quality, enhanced safety, and a more efficient brewing process.

Crafting a Solution

Form Factor:

Foremost, I needed a form that could breath, but the form must also be somewhat water resistant. The breathing part is obvious, but the need for water resistance arises from the fact that cleaning is an integral part of the brewing process. In an environment of constant cleaning, over spray should be expected and mitigated. Furthermore, the design should be slim and able to be wall mounted.

I was unable to find an off-the-shelf enclosure capable of meeting these requirements, so I opened Tinkercad and created a minimal, custom enclosure for the parts I had selected (see the linked STL files in the "Attachments" section).

Build:

The build was relatively straight-forward. Each component has a mounting point inside the enclosure specifically designed for the part. The wiring is also quite simple. The CO2 sensor connects to the UART, the screen connects to the Qwiic connector, and the button and speaker are each connected to a single GPIO pin. I also added capacitors to the button (to provide a physical debounce) and to the power supply for the sensor (to ensure the power was clean).

As you can see in the picture, I made a shield that fastens to the Notecarrier rails to make it easier to plug-in and unplug the components as I worked.

One important thing to note, is that you cannot place the cellular antenna near the OLED screen. The magnetic field created by the antenna during transmission will glitch the screen and put it into an unusable state.

Notecard Configuration:

The Notecard gives us the ability to realize the value of IoT with minimal effort.

• Remote MonitoringThe Notecard does this each time it sends a Note.
• Instant Alerts and NotificationsNotehub enables filtering and forwarding of important messages. This project will use a Twilio route to send alerts directly to my phone.
• Firmware UpdatesThe combination of the [Swan, Notecarrier-F and Notecard WBNAW](https://shop.blues.io/products/blues-starter-kit-for-north-america) are able to receive OTA firmware updates out of the box.
• Customizable AlertsBy using the Notecard's [evironment variables](https://dev.blues.io/guides-and-tutorials/notecard-guides/understanding-environment-variables/#understanding-environment-variables) the threshold for alarms can be mapped to the current activity of the bar.

Fortunately, the Notecard only requires minimal configuration to deliver all the value we just listed.

{
    "req":"hub.set",
    "product":"<your product ID>",
    "sn":"Brewmaster's Buddy",
    "mode":"continuous",
    "inbound":5
}

Industrial Safety Standards

IMPORTANT NOTE ABOUT CO2 STORAGE SAFETY CODES

This device is NOT CERTIFIED to meet requirements for CO2 safety monitoring which requires a Fixed/Wall Mounted, hard-wired alarm per the NBIC, NFPA, or IFC regulations, and therefore shouldnot be used in a commercial setting.

Conclusion

Embarking on this journey to enhance the safety and efficiency of my best friend's brewery has been an eye-opening experience. It's crucial to recognize that while DIY solutions like the one I've developed can offer significant improvements, they should always be seen as a complement to, not a replacement for, professional safety systems. The importance of adhering to industry safety standards and regulations cannot be overstated, especially in environments with inherent risks like breweries.

The CO2 sensor we've created is more than just a tool; it's a testament to the power of modern technology and the spirit of innovation. By leveraging the Internet of Things, we've transformed a simple monitoring device into a smart, responsive system capable of not only providing real-time data but also predicting and preventing potential hazards.

However, the journey doesn't end here. Continuous improvement is key in any field, particularly in safety. I encourage fellow enthusiasts and professionals in the brewing industry to use this project as a starting point, to innovate further, and to always prioritize safety. Remember, the goal is not just to brew great beer but to ensure that everyone involved in the process, from brewmasters to patrons, can enjoy it safely.

As for my friend, the brewmaster, and I, our adventure into the realms of brewing safety has only just begun. We're excited to see how our little project will evolve and how it will inspire others in the brewing community. Stay safe, stay innovative, and cheers to many more years of brewing excellence!