Its been about a month since our last update. We apologize for the delay. Unfortunately life finally caught up with us and sent all three of us out of town, or out of the country in Misha’s case, over the past 4 weeks. However, we were still able to work on the project and are getting super close to placing our full production run order. Over the past month several exciting things have happened.
Next week we plan on ordering a small batch of PCBs fully assembled, once we receive these back and they pass test we will order the final production run. Within the next three weeks we plan on doing the same with the plastics. We will make sure to keep everyone posted on this progress.
We have slowly been sending out surveys for the various reward levels. If you have received a survey but have not responded yet, please do so so that we can get your reward to you in a timely manner.
Thanks for your continued patience and support. We can’t wait to get your Model-T to you!
The BrewBit Team - Brian, Nick, and Misha
We received the latest prototype boards yesterday, so we spent this evening putting a few of them together. Everything is looking good other than one silly mistake: we left some of the ground plane under the antenna area. That is going to kill our signal for these boards, so we will need to spin them one last time.
Check out some pictures from the build:
In the last couple of weeks, we have been working on finalizing the PCBs for the BrewBit Model-T. This weekend, we finished up that work and ordered the next batch of boards. We are going to build up 10 complete units so that we can start doing lots more testing to iron out any last bugs before we go to production. Here is a list of updates that we have made to the design.
Improved LCD Interface
The STM32F205 microcontroller used in the BrewBit Model-T includes a cool peripheral called the Flexible Static Memory Controller (FSMC). This allows the microcontroller to easily interface with various types of external memory devices like flash or SRAM. It can also be used to interface with LCDs that use the 8080 or 6800 interface like the one used on the Model-T. The only catch is this peripheral is only available on the 100-pin packages and up. Our first boards used the 64-pin package, so we did not have access to the FSMC. Instead, we had to use GPIOs to bit-bang the interface. This works well enough for simple interfaces, but fast updates like animations are out of the question. With the upgrade to the 100-pin package the graphical capabilities of the Model-T are greatly improved.
Another nice thing about upgrading to a larger package, is we have lots of spare I/Os. We have broken these all out to headers so you can easily interface the control board with your own projects. In total, there are 38 I/Os including a number of UART, SPI, I2C peripherals and more.
New WiFi Module
The prototype Model-T used an Inventek Systems WiFi module. This is actually a pretty cool little device. It incorporates an STM32F205 microcontroller and a Broadcom WiFi module. The microcontroller runs the TCP/IP stack and interfaces to the hosting system (via UART or SPI). Unfortunately, the firmware that ships with the module leaves something to be desired. It is fairly difficult to do anything more complicated than a single basic socket or HTTP request at a time. We worked around this by writing our own custom firmware to run on the module and provide a more streamlined interface. We eventually got this working fairly well, but we weren’t thrilled with having to maintain two code bases for different parts of the project. Especially since, due to licensing restrictions we would not be able to share the source for the WiFi module.
Instead, we decided to switch to another WiFi module - the CC3000 from TI. We had been eyeing this module for a long time, the only issue was stock. TI seems to have ramped up production as there are lots of units available now. The interface is much nicer and supports a host of advanced features that were lacking with the other module.
Many products that require DC power simply use external AC/DC power supplies, generally in the form of “wall-warts.” This would have been our preferred route, but it really would not make sense for the Model-T. You already have to run AC power to the device since it outputs AC power, so why require a separate DC power input too?
There are a number of PCB mount AC/DC power supplies on the market. These are basically the guts of a wall-wart with pins allowing it to be mounted to a PCB. When we started the project we were pretty surprised at the cost of these modules. For instance on Digi-Key, the cheapest AC/DC power available goes for nearly $10 even in quantities of 1000. We talked to a few companies directly, but could not find anything less than about $7.
Because of this, we decided to look at what it would take to build a power supply ourselves. The first incarnation of the Model-T used a custom built switched-mode power supply based around the Power Integrations LNK616PG switcher. Most of the parts for this power supply are available off-the-shelf. The exception was the flyback transformer. We were able to find one that worked and got the power supply up and running without too much trouble. In the end, this power supply was going to cost us around $4.50.
With that seemingly settled, we moved on to the other portions of the project. Fast-forward a few months, just before the Kickstarter launch when we started talking to the various product certification labs. One of the first things that they told us was that AC/DC power supplies are subject to heavy scrutiny. This scrutiny can cost a considerable amount - we were given a ball-park of around $12-15k. Needless to say, we were a little taken aback. Clearly our “cheap” $4.50 power supply came with some serious hidden costs - including certification this option would cost us nearly $30 per unit for the first 500 units! Those $7 power supplies were starting to sound pretty good now. In the end, we were able to find a good quality AC/DC power supply that comes with UL/CE certification for $6.50.
The first Model-T prototypes used the power board itself to route the AC power from the input to the outputs. This was a clean and simple design that is easy to assemble. In total, there were 3 AC power headers on the board - the input and two outputs. The input is routed to our AC/DC power supply as well as the two outputs which are switched with relays on the same board. However, as we started to think more about safety and reliability, we started to worry about the current carrying capabilities of the PCB traces and solder joints on the board. Even though we had designed in very thick traces, we weren’t entirely comfortable with routing this power on a PCB. After reading a few horror stories about fried traces and solder joints, we were convinced that we should move this off-board.
We have since switched to relays that use PC pins for the control lines, and quick-connect terminals for the contacts. The quick connects will be connected to the inputs and outputs with 14 AWG wire which will let us carry much more current, much more safely.
We have interfaced thermocouples to the Model-T in the past using an Arduino and a standard thermocouple amplifier. This works great, but we wanted a sleek integrated solution, so we decided to build a board around the DS2762. This chip is actually a 1-wire lithium ion battery monitor chip, but it includes a very accurate millivolt level ADC - perfect for reading thermocouples! There are a couple of articles around the net showing how to use this chip for this purpose. Our board had two connectors: an RJ-11 connector that you can use to connect to the Model-T sensor interface using a standard phone cable, and a standard thermocouple connector allowing you to easily connect any thermocouples that you might already have.
We also just learned that Maxim recently launched a new chip that is designed specifically to adapt thermocouples to the 1-wire bus - the MAX31850. Stock is pretty limited at the moment, but we have some samples on the way and will be putting together some boards soon.
While preparing to launch our Kickstarter campaign, we decided to have some fun and build a small ferementation chamber using a small fridge.
Our inspiration came from Broken Glass Brewery post
The build process and the result you can see in the video below.
The chamber is designed to fit 3 carboys or 2 carboys and a small keg with a few beer bottles and brewing supplies. It’s fairly easy to adjust the dimensions to fit only 1 carboy and fit inside a small apartment.
I’d like to take you step by step through the build process and provide plans at the end.
Went to HomeDepot and got a bunch of things, including a floor-model 3.5 cubic feet fridge.
The fridge is a Magic Chef Stainless Look
First step was to remove all the shelves, door, legs and bend down the freezer tray to get the most space. Then we started building the bottom frame.
This was followed by the vertical supports to hold the fridge in place and provide space for up to 3 carboys.
The top frame was constructed next.
We ended up building it piece by piece instead of assembling it entirely and then fixing it to the frame. On reflection, this might not have been the best idea as we’re not fantastic carpenters and measuring 2x4s after a few beers does not produce the best results. We think we made up for it later though.
We sealed with silicon calk the major areas we were concerned with before starting on insulation. This was the most time-consuming and difficult task.
We put in some pieces in the bottom to provide support, followed by the “floor”
After that we started measuring and cutting pieces around the two sides. We used a very sharp knife, which cut down on the amount of insulation bits floating around.
At this point we stopped with insulation and started taping everything down. This allowd us easy access to all the nooks and cranies without having to contort in all kinds of painful ways. I would say this took us the longest amount of time, about 3-4 hours.
The most difficult portions were the corners. The trick we figured out was to work in small segments and pre-bend down the length and then peel back the first half, stick that down and then peel and stick the other half. If you stick to about 4-6 inches for each length, it’s fairly easy and doesn’t stick back on itself.
With that task complete, we cut the inside wall and inserted that in. Taping it down at this point would have been impossible, so we turned the fridge on the side and I climbed in and started taping.
In 85+ degree weather it’s not the best thing in the world, but we had plenty of beer on tap, so that helped.
Having finished that we stopped for the day. The next day we started filling in all the openings with more insulation.
This went a lot faster since we could get to each part easily. We did realize just how crooked our framing was at this point, but we made up for it.
Once we had all the insulation cut and placed, we taped it all down.
We didn’t want to leave it like that so we got some 1/8” plywood sheets and covered the frame with them. It provides a more pleasant view than all the insulation, plus it helps protect the fragile insulation wrapping.
We didn’t stop there though, ugly corners are not something we want around, so we got some corner guards and attached them.
Originally, we were thinking of using the fridge door as the lid; its already insulated and has hinges, but it was too small, so we made one from a 1/2” plywood. Attached a handle and a hinge stop and were getting to mostly done.
The “piece de resistance” is, of course, BrewBit Model-T! We built a small pedestal for it, run a probe to an RJ-11 phone wall plate and inside the chamber and attached everything together.
We also added some insulation to the lid to sit inside the opening. While we’re not in Arizona, San Diego does get hot, and we don’t want to risk ruining a batch.
To finish off the unit we want to stain the wood and put on a polyurethane coating. That should help with any spills and humidity.
We also need to install some kind of flooring cover to protect the insulation. Linoleum seems like the best option at the moment as it’s cheap and easy to clean.
Hope you enjoyed reading about our build as much as we enjoyed building it. If you’d like to build your own, here is a list of parts and some drawings of the various dimensions (Apologies for crudeness):
The total cost ended up just under $200, not counting the BrewBit. We had some parts so that shaved off $50-$80 from the total build. The fridge was a floor model, so ended up being a lot cheaper too.
A lot of people have been comparing the BrewBit Model-T to the BrewPi, and in a lot of ways this makes sense. The two have a number of features in common: remote monitoring and control, open source hardware and software, similar temperature accuracy and precision, similar output current rating and more. Despite these similarities, there are a number of key differences that we think make the Model-T stand head and shoulders above BrewPi.
AC power is extremely dangerous. If not handled properly, you can end up damaging your property, causing an electrical fire, or even fatally electrocuting yourself. BrewPi does not provide standard pre-wired electrical outlets. Instead you must manually wire it up using screw terminals. Mix up two wires and you can create an extremely dangerous condition just waiting to happen.
We take these risks very seriously which is why the Model-T comes pre-wired, tested, and ready to use safely from the moment you take it out of the box.
We have seen several claims that BrewPi is cheaper than the Model-T. Our initial rough estimate of actual BrewPi pricing showed that they were very close in price, however as more people made this argument, we decided to take a closer look. Based on pricing from the BrewPi store and Amazon, here is what we found:
Already, the BrewPi is nearly $90 more expensive than the BrewBit Model-T. Due to the fact that the BrewPi is not plug-and-play, you will likely need to purchase additional parts in order to integrate it into your brewing/fermentation systems adding even more cost to an already costly project. In our Kickstarter comparison chart, we made a conservative estimate of $15 in additional costs to complete a BrewPi build, bringing your total to nearly $260.
BrewPi comes with a basic character LCD which displays the current temperatures and status. In order to interact with it, you use a rotary encoder. This interface works well enough, but feels a bit antiquated in the age of smart phones and tablets.
We think that the full-color touch screen display on the Model-T offer a much more natural mechanism for interacting with the device while also allowing for an extremely flexible and beautiful platform for displaying status.
BrewPi is composed of two general purpose control boards (Raspberry Pi and Arduino). We believe that this architecture has a couple of downsides:
Wasted resources - Do you really need a 700Mhz ARM processor, GPU capable of playing 1080p video, 512MB RAM and a Linux OS just to read a couple of temperature sensors and switch some relays?
Size - The Raspberry Pi and Arduino boards end up taking much more space than a purpose-built integrated solution.
The Model-T integrates an appropriately spec’d microcontroller into custom made PCBs which are designed to fit compactly into the case and reduce the cost and complexity of the final device.
BrewPi uses a laser-cut acrylic case. Some people find this DIY look to be charming, inviting the user to crack it open and hack away, and indeed it can be. Others don’t care about seeing the internals and just want a polished finished enclosure. This matter is largely a matter of taste, but we wanted the best of both worlds with the Model-T. It comes in a nice, finished, injection molded case, but is easy to crack open and hack for the more technically inclined.
BrewPi is largely aimed at programmers. They have done a nice job in writing instructions to help less technical folks to get it up and running, but there is no avoiding the command line.
Model-T on the other hand is ready to rock out of the box. For those that prefer to take the less travelled path, all the source code, schematics, and tools you need are available for your hacking pleasure.
BrewPi offers an impressive platform for beer monitoring and control. In many ways it equals the BrewBit Model-T, however in the end BrewPi is more expensive and less user friendly. Model-T is just as hackable as BrewPi while also offering a simple route for non-programmers along with a number of features above and beyond those of BrewPi.
What do you think? Did we miss anything?
After receiving a large volume of feedback from international users we decided to go ahead and add reward levels for you. We hope you will back us and help spread the word to other international users that they too can own a BrewBit Model-T.
Thanks for your help and support!
Get your own BrewBit Model-T now on Kickstarter:
- The BrewBit Team
Get your popcorn ready for the launch of BrewBit Model-T!
We got our final approval last night!
We’ll be launching Monday morning, get your carboys ready.
We submitted our updates to Kickstarter and are, impatiently, awaiting final approval.
Given that the changes requested were very minor, we’re hoping it won’t take long.
In the mean time, hope you’re enjoying your beer
We got an email today from KS on our campaign. We have to make a couple of minor tweaks and then we’re good to go.
We’ll have those changes done tonight and resubmit to KS. Hoping the second review won’t take very long!
Wanted to give everyone a small update on what we’re doing while waiting for KS to approve our project.
Our main focus this week has been on putting together a press release that we’ll be sending out to various news outlets.
In addition to that, we’re finalizing some of the manufacturing prep that is needed. This includes testing devices at the factory.
Brewbit team - Nick, Brian & Misha
The video is done. A few minor edits to the Kickstarter page and we’ll be submitting it tonight.
We drank a lot of beer and shot a few hours of footage but the biggest lesson from making the video is not to quit our day jobs as engineers.
We’ve been spending this week shooting all the footage and voice recordings for our video.
Now it’s time to take all those hours of footage and turn them into something you’ll want to watch.
We’re almost ready to launch…
We’d like to share with you what we’ve been up to since our last update, at the beginning of the year. A great deal has happened in the last six months and we’re really excited to tell everyone about it.
In January, we hit a wall. Our very early prototypes of the Specific Gravity sensor showed some promise, but as we worked to scale the sensor down from the size of a box of cracker jacks, to something that would fit inside of a carboy, the achievable performance became unacceptable. The performance could be improved, but it would require some serious engineering rework and would likely end up costing considerably more than we were initially targeting. With that said, the SG sensor project is not dead. We are currently exploring other sensing techniques and designs to reduce cost and complexity.
Faced with this, we decided to take a step back and evaluate our options. After some brainstorming and going back to our original market research, we realized that the number one reaction that we were getting from people when describing the SG sensor was: “That’s cool! But does it integrate with a temperature controller?”.
Originally, that idea seemed interesting, and we had been planning it as an add-on to the SG sensor. However, the more we looked at it, the more we realized that a temperature controller is exactly what we should be building.
Having spent time fiddling with ones available out there, we were convinced that a high-quality temperature controller that can record all the data and automatically adjust based on specified presets is exactly what everyone needed to brew better beer. In fact, if you could only do one thing, aside from sanitizing properly, to make better beer, it would be to control your fermentation temperatures.
Temperature control is one of the most important and critical elements in taking your home brewed beer to the next level. Temperature control is often overlooked by many homebrewers but is actually one of the easiest things you can do to make “professional” quality beer. Whether you brew extract beers, partial mash, or all-grain, there is always some element of the process that can be improved upon using a temperature control device.
The Model-T will help you keep your fermentation and mash temperatures within one degree of where you want them to be. Allowing you to end up with a beer that you can be proud of!
Our goal is to build a family of devices that all work together to give you a unified picture of what’s happening to your beer through all the stages, from mashing to fermenting. We want to give everyone affordable tools to brew better beer and the Model-T is the first step towards that. How you ask? Initially, we’ll be offering the following features:
Open Source hardware and software. You’ll get all the schematics, drawings and software. Hack away and share your work with the BrewBit community!
Wireless connectivity over your WiFi network
Execute temperature profiles loaded via WiFi connection from your account on BrewBit.com.
Control from anywhere with Internet connection
SexyUI (tm) ;)
Dual independent outputs
Dual independent temperature probes
Control one, both, or none (logging only) of the outputs
Associate your data with a defined brewing session.
Wirelessly upgrade your unit when we roll out new software.
Free API for your data and device. Develop your own killer features!
Modify all of your Model-T’s settings and have them applied over WiFi
Check on the units status and readings
Log the Model-T’s data
Display temperature graphs that are updated in real time
Associate temperature readings with a certain brewing/fermentation session.
Get email or SMS alerts when something happens or the unit is having issues
Create and save unique temperature profiles
Load a profile and send it to your device over WiFi.
Set the Model-T to ferment/mash your beer for any duration at a set temperature.
Step the temperature up or down automatically
Add as many temperature/time steps to the profile as you need.
Plus more to come… (feel free to pass on your ideas and suggestions!)
We have produced several working prototypes of the final product using 3D printed plastics and PCBs from a manufacturer in the USA. We manually hand placed all the PCB surface mount components and soldered the through hole ones ourselves. We have gotten the units fully working and operational and are even using one of our prototypes to control our keezer and fermentation cabinet.
At the same time, we are working on our website, where you will have full control and status of the unit.
We’re putting finishing touches on our Kickstarter campaign. Once our video is finalized, we’re ready to go.
We have all of our manufacturing partners lined up and ready to go. Once our Kickstarter campaign is funded, we will immediately start the manufacturing and assembly process.
Please spread the word about us. Our main line of communication and support has been this email list. We’ve gotten lots of great feedback and support from you, please keep it coming.
We would really appreciate you sharing us with your friends. Check us out on:
We’ll send out an update within the next 3 weeks when we’re launching.
Thank you to everyone for hanging in there and all the support!
- The BrewBit Team - Brian, Misha, and Nick
A little taste of our latest brew
We have been quiet for the past couple of months, but rest assured, we have not been idle. So we wanted to give you a little nudge, remind everyone that we are still here, still slaving away over a pint of cold beer. Since our last email, we have gone through many tests, a few prototypes and a lot of drinking.
In this newsletter, we’d like to tell you more about BrewBit, our troubles and our plans. So here goes.
We’ve posted in a few places how BrewBit works, but we have not done so as widely as we should have. So first off, we’d like to tell you more about BrewBit internals.
BrewBit is a miniaturized wireless digital refractometer. That’s a mouthful, but what it means to you, is that it goes inside any fermenter with an opening at least 1 inch (2.54 cm) in diameter and will wirelessly send temperature and specific gravity to your computer about how your beer is fermenting.
The refractometry bit means we shoot a light into a prism that is in contact with the your brew. Depending on how the light refracts (bends) inside the prism, it tells us the specific gravity at that time. The temperature bit lets us auto-correct the specific gravity readings so that they are accurate and tells you when you need to turn up the heat or find a cooler place.
Pretty basic stuff, until you try to fit it into a tube that is less than 1 inch in diameter made out of food-safe plastic.
The physics driving how the prism looks and how the light is shone into the prism affect everything about the device; from the internal shape of the device itself, to the positioning of the electronic components, to the kind of sensor we can use to measure the light.
Plus, we’d like it to last as long as possible so you can get as much data as possible. Oh and don’t forget food safety. We wouldn’t want you to end up with a beer that tastes like plastic or worse, causes you to grow an extra arm (though that can be useful to hold another pint; we can look at this as a feature in one of the next models).
This brings us to where we are currently.
Our current prototypes are not delivering the accuracy that we had hoped they would. After a few pints and a few tests, we think we’ve found a few options to try out, but this means manufacturing new optical components.
Redesigning the optics does not affect our final price, but does affect our timeline by extending it out to the summer of 2013.
Why does it take that long, you ask? Well, we need to design a new optical system, and analyze it to ensure that it will meet our performance standards. To this end, we’ve built a custom optical design software package as the existing ones are too expensive and don’t work for our case well. So in the coming months, we’ll be exploring our options, ordering a few different versions and seeing what works best.
The problem with changing optics is that it causes a ripple effect that means changing plastics and electronics.
Changing plastics means going back to the manufacturer and redoing all the molds that we spend a lot of time designing.
Changing electronics means new boards, potentially finding new components, because the old ones no longer fit, retesting wireless, redoing all the work for FCC certification, dealing with changes to power and retesting batteries.
Each of those things takes time, which means we have to delay launching BrewBit.
It’s not all gloomy though.
We are committed to launching BrewBit and giving everyone a product that works in any fermentor with any fermentation style for a pro or a novice alike.
There are Kickstarter projects that have had trouble delivering their rewards on the timeline they promised. In most cases, this is caused by the project starters launching their project before they have a production-ready design. This outcome quickly turns the excitement of the backers into frustration. We are committed to avoiding this situation by designing for production from the start, and waiting to collect money until we are fully ready to use it. When we launch, you can be certain that we will deliver the device you want to use and deliver it on time.
We’re working very hard to solve our optics problems and getting the rest of the product squared away so we can give you an amazing experience!
We’re also working very hard on the companion site that will show you the data BrewBit collects, but we’re not stopping there. Will also give you the tools to make sense of the data and help you Brew Better Beer.
Watch this space for more on that and happy brewing…
After working with the initial prototype we found some issues that needed to be corrected. We got the new circuit boards in as well as a docking station for the BrewBit to sit in for recharging.
The BrewBit is keyed so that you cannot dock it backwards. The charging contacts will only slide in one way.
Here is a before picture of the bare board that will go inside the BrewBit.
We used a laser cut stencil to apply the solder paste to the board and then we hand place the parts. This process is pretty tedious and takes about an hour or more per board. We are using the green boards around the black one to hold it securely from moving while we place the parts.
After the parts are placed we use a toaster oven to re-flow the solder and secure the parts to the board. Once that is complete we have the finished board ready for action.
To make sure it was all working we programmed the micro controller with some test code and used a logic analyzer to verify that we could stimulate the different pins on the board.
So far so good!
We are now in the process of developing the RF (wireless) code so that we can test out that part of the circuit and get it talking to the base station.
After a long weekend of work the assistant brewer thought it was time for a couple cups of tea. We couldn’t have agreed more!