Second Prototype Boards Arrived

The boards for the second prototype arrived a couple days ago.  Very exciting.  I have unpacked a set and taken the picture below.  The top board is the camera board.  The left board contains the amplifiers and the right board is the brains.  I have tried to fit the boards into the new prototype case and there are a few 'boo-boos' but nothing we can't fix.  Mostly the problems are in the height of the boards.  In a couple of cases, I failed to leave enough room for the connectors to clear the walls of the case.  

Next task is to get the boards booting and see if I can make some music.  Keep your fingers crossed!

Second Prototype Case Done

We had the second prototype case printed at Shapeways and it arrived this past week.  For the most part, it all fits together as planned.  Of course, there are some boo-boos but nothing that wasn't correctable with the Dremel tool.

Here are some pictures of the of the case while I put it together.  Click any image to get a closer look.

Second Prototype Boards Done

The boards for the second prototype are done.  The basic functions have been verified.  They will be shipped from our partners in China the week of September 5th. 2016.  

Below is the first picture of all the boards.  The board on the left is the amplifier board (this is the board that makes the music!).  The board in the middle is the SOC board, which is the smarts of the system.  The board on the left is the camera board.  We have 10 complete sets of boards so we can do plenty of hacking.  Let the fun begin! 

New Case & Electrioncs

With the new architecture described in the last post we decided to try to implement a new case design that followed the concepts provided by the Industrial Designer.  We also decided to try new form factors for the new electronic design.  This was ambitious and took some time to see through to fruition.  However, the payoff is now very close.  We will have all the pieces for the second major prototype done by the end of August.  We should have a working second prototype sometime in September.

Above is a rendering of our new case design.  The image on the left is a collapsed view of the case.  The image on the right is the expanded view of the case that shows all the various pieces that make up the case constructions.  The two grills (the blue panels with the hatch pattern) will be wrapped in speaker wrap during the final construction.  All the pieces you see in this model are ready for mold making.  For the prototype, we will CNC and 3D print the pieces to verify that they all fit together.

While we were working on the case design, we also finished the schematic design and layout of the electronics.  In the case renderings you see above, the green boards are the camera board (front green board), amplifier board (top green board) and the SCO board (back green board).  The following is an image of the layout.  These boards are currently being assembled

We are on track for having a second prototype assembled by the end of August.  We will be making it fully functional in September.

New Architecture

Our first prototype was very price efficient but not development efficient.  We used a common camera processor as the main processing unit.  That processor was adequate for our hardware needs.  However, its software support was hopelessly out of date.  We had to back port several drivers for modern peripheral chips (like the wifi module and the sound chips) into a kernel that was not designed to handle them.  Very quickly, we found ourselves reinventing interfaces in the older kernel which would have led to system instability.

In addition to the software problem, our original architecture did not allow for any room to grow.  If, in the future, we wanted to add special video and/or music processing the camera processor CPU would not be able to handle it.  It was already performing at its peak ability.

To fix this problem, we decided to re-architect the product around a more powerful processor with good software support.  Especially important to us was to pick a processor that had broad application and deep community support.  For these reasons, we decided to use the Allwinner A64.

The Allwinner A64 is a popular processor for tablets.  The kernel is reasonably up to date and there is an active community providing support.  Since our product could be viewed as a tablet with a couple of amplifiers add, we felt this was the perfect choice.  It is powerful, reasonably priced, available in mass production and reasonably well known by current manufacturers.  Below is a block diagram of the new architecture.

The new architecture retains all the functionality of the old architecture but has a much more flexible and powerful processor at its core.  

The new architecture retains all the functionality of the old architecture but has a much more flexible and powerful processor at its core.  

We spent June and July creating a new schematic and layout for this new architecture.  That effort is complete and new boards will be available at the end of August.  While we did this work, we also implemented a new case design following along the guidelines developed by the Industrial Designer.  That effort will be documented in the next post.

New Product Look

New cylindrical DigiSpeaker design.

Although we haven't posted in a while we have been busy.  In May we decided to pay an Industrial Designer to come up with a better looks for DigiSpeaker.  The Designer came up with several looks but we liked the one you see on the left the most.  It is a cylinder with the camera mounted on the top of a control panel that has an on/off button and volume buttons.  Various connectors are arrayed on the back.  We liked this design because of its simple clean appearance.  Also, it can be comfortably placed on a bookshelf, fireplace mantel, or on a side-table.  We also thought it met our criteria of being a decor item (something that can be proudly displayed in a home) without being a piece of art (something that draws too much attention).  


Trip to China


Jon and I had long wondered about manufacturing in China.  Of course, you hear a lot about the low labor rates and a well developed supply chain.  But you also hear about a lot of disasters as well.  To clear up this mystery I decided to take a trip to Shenzhen, China in January of 2016 to see for myself.

As our goal, we decided to have our first prototype constructed in China.  We figured this would give us some hands-on experience with Chinese manufacturing and also give us a chance to wander through the various factories and markets.  Furthermore, we figured to get the most out of manufacturing in China we needed to do things the 'Chinese way'.  To us, that meant using the tools and parts commonly found in Chinese manufacturing.  So, the first DigiSpeaker prototype was designed with tools that are commonly used in China and also uses parts commonly found in the supply chain in China.

The first part, using tools commonly found in China, was pretty simple.  It turns out, they pretty much use the same tools and techniques we use in the United States.  That was good news since it was easy to transfer our design documents to the Chinese without much hassle or communication problems.  The process was very similar to what we normal do here in the States.

However, the second part proved to be harder.  DigiSpeaker was designed with parts commonly found in the supply chain in China.  For common components like passives, diodes, transistors and whatnot, this meant identifying the brands that are most commonly used in China.  For more complicated parts, this meant learning to interpret specifications written in Chinese.   As you can imagine, this took a lot of false starts and stops until we found ways of identifying common parts and obtaining datasheets for the more complicated parts.  In addition, it takes a while to figure out how to purchase things from the Chinese markets.  Of course, there are the payment and shipping complications.  But there are also basic misunderstandings about what is available and what to purchase.  

In the end, we were able to design our first prototype using techniques and parts available in China.  So, the next task was how to get to Shenzhen and where to live once we got there.


In order to conduct business in China you have to have a business visa.  To get a business visa you have to obtain an invitation from some company willing to sponsor your trip to China.  Fortunately, Jon struck up a friendship with a person who currently has a project under construction in Shenzhen.  He was willing to give us a hand.  He asked his current factory to write me an invitation letter.  With that letter, I used a passport expeditor service to get a Chinese business visa added to my passport.  

I live in Seattle and there are direct flights from Seattle to several major cities in China.  I soon found myself on a flight to Beijing and then on to Shenzhen.  Our friend has an apartment in Bao'an Shenzhen so he was able to meet me at the airport.  The next day, he let me tag along with him to the factory that was making his product.

With my design in hand, a place to lay my head at night and an invitation to tour a factory, I was on my way.


Shenzhen Allied Controls

Shenzhen Allied Controls is the factory where I initially spent most of my time.  This factory makes control systems for heating and cooling systems.  They are a pretty large operation occupying 4 floors of a large building in the industrial district near the Shenzhen airport.  

My friends project was HVAC related so this factory was a perfect partner for them.  Although they were not a good fit for DigiSpeaker, they were kind enough to welcome me to Shenzhen and begin to teach me the ropes.  I was able to meet several of their engineers and technicians.  They were kind enough to answer my questions.  Most importantly, they recommended friends and other businesses that might be a better fit for my product.  I am very grateful for their kind welcome and invaluable assistance getting me started in China.

Huaqiangbei Markets

One of the things the Shenzhen Allied Control people did for me was to tell me how to get to the Huaqiangbei Markets in downtown Shenzhen and how to navigate them.  With their help, I was able to ride the subway downtown and begin to wander through the famous electronics market.

My first impression of the markets was WOW.  It was pretty overwhelming.  As an electrical engineer I had never visited anyplace quite like it.  Building after building.  Floor after floor.  Shop after shop of electronic goods.  They sell everything here from the lowliest capacitor to the most sophisticated cell phones, drones and robots.  Best yet, it all takes place in a rockus, loud, crazy environment with deals going down all around and pallets of products headed for the loading dock.  My first day walking through it all is a blur.

After a day or so of walking around the markets you begin to get a sense that there are great deals to be had but it is all pretty random.  One thing you notice, however, is that all the shop keepers are doing one of two things all the time.  They are on their computers or they are shipping product.  You see people doing business but it is pretty difficult to walk in cold to the markets with your bill of materials and start buying.  A better strategy is to use the parts websites like aliexpress or ic37 to locate parts you are interested in.  Then email/chat with those vendors from the comfort of your hotel room.  When you are confident you have a list of vendors that have the parts (and prices) you want, then it is time to hit the market and start negotiating.  There are good deals to be had but it takes work and a willingness to walk down some dead-ends.

Seeed Studios

Seeed Studios is a famous maker shop in San Francisco that has an office in Shenzhen.  They specialize in helping entrepreneurs get started on their products with high quality construction of low volume prototype.  They also will list your products on their website when you are ready to start marketing your product.

I had read about them in various blogs and noticed that they had an open door policy so I dropped in on them one day.  They were very welcoming and were kind enough to give me a tour.

The people at Seeed Studios were kind enough to reviewed my design and suggest some changes that would make manufacturing of my devise in China much easier.  As I had suspected, one key to reducing cost and trouble when making something in China was using parts easily sourced from their local suppliers.  Seeed Studios reviewed my design and BOM and sent me back a spreadsheet with a number of part changes that I have since incorporated into my design.   

Rising Electronics

Rising Electronics is a medium sized music player and speaker manufacturer that has a factory in Dougguan, China.  It is a short train right from downtown Shenzhen.  Jon had seen a video of their operation and asked me to check them out.  I sent an email to the manager and I soon found myself riding a train out of the center of Shenzhen.  The ride was fast and smooth.  The Chinese know how to run a railroad.

Rising Electronics makes several lines of music players from small handheld units to big units meant for dance clubs and party spaces.  They make the electronics, cases and speakers.  They have several hundred people working in their factory.  They ship several thousand units a month to their markets in the Middle East and Africa.  They are a good fit for manufacturing DigiSpeaker.

The manager welcomed me warmly and took me on a tour of his factory.  He has an impressive amount of equipment and staff.  Hand assembly lines.  SMT assembly lines.  Several large presses for making the cases.  They are well equipped for making several thousand DigiSpeaker units a month and shipping them.  They also have a small design staff that can modify designs so they best meet the capabilities of the factory.  

This was a very informative visit and a good possibility for manufacturing of DigiSpeaker.  We have kept in touch since my trip to China.

People & Places...

I have traveled around North American and Europe quite a bit but I must admit that I wasn't prepared for how different China was.  Quite literally you can't understand a thing around you.  It is very disorienting.  Fortunately for me, I met some wonderful people that were kind enough to lend me a hand.  English is not commonly spoken so I struggled a bit getting directions and even ordering lunch.  But everywhere I went people went the extra mile to help me out.  For that I am very grateful.  The people in the factories, my driver, even the lady that sold me Baozi (Humbow) for lunch.  They all had a smile for me and tried their best to help me on my way.

Below are a few pictures of the people I met and the places I saw while I was there.  Of course, I have lots more pictures.  This is just a small sampling of what it is like to wander around Shenzhen.


Our goal in visiting China was to make our first prototype of the unit.  This goal was largely achieved.  The good people at Shenzhen Allied Control were kind enough to have my boards made by a local PCB house.  They also were able to assemble three boards for me to take home.  In addition, they hooked me up with a local CNC milling shop that was able to take my 3D drawings and turn them into a prototype case.  The results are shown below.

With a fully constructed prototype in hand and a very informative trip done, it is now time to make the system work for real.  But that is left for another post...

First DigiSpeaker Prototype

In December of 2015 we completed the design of our first integrated security system and bookshelf speaker.  The unit is roughly 200mm square with a main processing board hung on the back and a camera sensor board mounted in the front.  The case houses a pair of two inch full-range speakers and a four inch down firing woofer.  It has about a four liter volume and a five inch port with a one inch opening.  Theoretically, the case should have good response down to around sixty hertz.

The main board has a camera processor on it.  It also has two forty watt digital signal processing enabled amplifiers on it.  It is capable of being driven from an external power supply, a USB connection or an internal battery.  It has integrated wifi and ethernet.  It also has a 433MHz transceiver, microphone, light sensor, and other various sensors that provide a range of environmental measurements for the system.  

Three dimensional CAD drawings were done of the case and prepared for submission to a CNC milling factory for construction.  Also, layout files, bill of materials and assembly instructions were created in preparation for having the boards constructed.

Below are a few pictures of the first DigiSpeaker prototype. 

Early DigiSpeaker Concepts

Below are a few pictures of early DigiSpeaker concepts and experiments.  Mostly we were interested in product form factors and technology experimentations.  We knew that we wanted to make a bookshelf speaker with good sound and a forward facing camera.  The idea was that the unit would be placed on a bookshelf in a room so it had a good vantage point for scanning the entire room.  We experimented with various camera sensors and lens.  We also experimented with various amplifiers and speaker arrangements hoping to get good stereo imaging and high quality sound from a single unit.  Click through the gallery to get a sense of some of the work.