This board plugs into an Arduino Uno R3, and it provides the sockets for plugging in the SainSmart LCD/keypad board. The LCD provides the user interface to select various crossover frequencies, BSC, EQ and volume trimming. A completed board is shown below:
When the boards are stacked together, they look like this:
You can make your own boards by simply sending the zip file in the link to ITEAD studio. You can buy 10 bare boards for $43 including shipping, although you might want to spend a bit more on premium shipping because it will take almost a month to arrive using standard shipping.
If you want to make changes to the design, you will need to install DesignSpark (a free download) and open up the ADAU1701_shield_RCA.prj file. The schematic and PCB files will need to be in the same directory as the project file (.prj). The schematic may not have the exact part numbers, because I wasn’t overly careful about updating every library part. However, the Excel file should have the right part numbers, along with Digikey’s ordering numbers.
I should probably get some beer icons to indicate how many beers you will need to consume to assemble the boards. I’d give this one a 2-beer rating. It turns out these boards aren’t all that time-consuming if you have a basic hot air rework station. I just put some solder paste on the SMD pads and placed the parts on the solder with the tweezers, cleaning the tweezers periodically with denatured alcohol to keep the parts from sticking. Every part on the part is 0805 or larger, so you won’t go blind. The ADAU1701 chip is probably best soldered on by hand using a temperature-controlled iron and a fine tip. Just get a few pins soldered to hold the chip in place, and then use lots of solder and flux to make sure each pin is soldered to the board. Of course, that will create lots of solder bridges, but use fine braid to remove the bridges, and touch up by using extra flux and heating up each pin with the tip of the iron. I’ve ruined an ADAU1701 by trying to solder it with the hot air tool, but I’ve soldered at least 30 of those 64-pin chips using the hand soldering method described above, with no problems. Notice that I put a rectangular opening in the ground plane under the chip, so you can shine a strong flashlight from the back of the board to inspect the solder joints.