Original introduction(in Chinese) to the board by the hardware designer
1. Peripheral Summary
13 x GPIO
2 x UART
1 x I2C
1 x SPI
4 x PWM
1 x ADC
2. New Hardware Features
a) Auto-Flash and Auto-Reset circuit
The designer of this board Kevin Chen added an auto-flash/reset circuit to the board and with the another maker jojoling auto-flash program, you will be able to download firmware into the board without the need to press buttons on the board when using Arduino IDE
b) Power LED
It's wired to not have an power LED -- unlike computer with screen, MCU without LED is hard to tell whether it's properly powered on, therefore, the designer added a power LED which is missing from the RTLduino(BW16)
c) BW16 Factory Firmware Already Erased
One of the things that are bugging most RTLduino(BW16) users is that the factory default firmware prohibits users from booting into their own Arduino firmware, and this is no longer the case as all boards are pre-processed and factory firmware already erased, it's all ready to be programmed by Arduino IDE
d) Battery Connector Added
Many maker like to take their project and delpoy it somewhere far from USB connection, a battery is really handy in that case. Designer added a JST 2.0mm battery connector, when USB power become available, the core will automatically start drawing power from USB instead of battery. (Note that charging LIPO battery on this connector is not supported)
e) Bigger Buttons
Pressing buttons on board of this same is usually abit of trouble, so designer has chosen a bigger button which make it quite easy to find and press with better accuracy.
f) Adding More Useful features via jumpers
Designer has added 1 built-in LED and 2 pull-up resistors to the SDA and SCL pins of I2C, but these features are not enabled by default -- this is to make sure that all pins can be used as GPIO and are as flexible as possible, you can always enable them by shorting the solder pads on the back of the board using abit of solder or jumpers.
3. Things That Are Not That Perfect Yet
After using it for a while, there are a few things I noticed which could be improved,
a) Some silk screen covered by components
Some pin's silk screen are covered by components, though doesn't affect readbility, but it will definitely look nicer if it's not covered.
b) Pins are not arranged in sequential order
Each pin are given a numberic name just like the rest of the Arduino boards and I guess most makers are used to pins arranged in the sequential manner -- that is Pin 2 next to Pin 1, 3 next to 2 and so on so forth. This can be done on the hardware or software, so hopefully it can be updated in the laster version.
There are much useful information online, part of which can be found down below, or else, you may consider joining the Realtek's official Facebook group for this board at https://www.facebook.com/groups/amebaioten/