Introduction to BW16

Note: Original post in AmebaIoT Forum that supported with Dual Language: [Resources] BW16 Getting Start Guide

Required Environment

RTL8720DN Dual-Band Wi-Fi board currently supports Windows XP/7/8/10 32-bits and 64-bits operating systems. In this documentation, please use Arduino IDE with version 1.8.15 or later.

Introduction to BW16

Realtek RTL8720DN is a Wi-Fi and Bluetooth IC that supports 2.4GHz and 5GHz dual bands for Wi-Fi communication, and Bluetooth Low Energy (BLE) 5.0. BW16 is a module manufactured by B&T, this module is a highly integrated Wi-Fi and Bluetooth module with the RTL8720DN as the main SoC (System on Chip), it can be regarded as an SoC for the Wi-Fi and Bluetooth application with typical SBCs.

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RTL8720DN (BW16) has a smaller size than AmebaD and AmebaD-MINI as shown in the above figure. It uses Micro USB to supply power, which is common in many smart devices.

Please refer to the following figure and table for the pin diagram and function of RTL8720DN (BW16).

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Screenshot 2021-08-04 111146.jpg

Setting up Development Environment

Step 1. Installing the Driver

First, connect RTL8720DN (BW16) to the computer via Micro USB:

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If this is the first time you connect RTL8720DN (BW16) to your computer, here is something that you might take note of:

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The pins LOG_UART_TX (GPIOA_7) and LOG_UART_RX (GPIOA_8) are used for program upload. However, the onboard USB-to-UART module is connected to LP_UART_TX (GPIOB_1) and LP_UART_RX (GPIOB_2) and thus cannot be used directly for program upload. You can choose to either use an external USB-to-UART module connected to GPIOA_7 and GPIOA_8, or you could short these pins together to use the on-board USB for program upload:

GPIOA_8 ––– GPIOB_1

GPIOA_7 ––– GPIOB_2

After connecting accordingly, the USB driver for RTL8720DN (BW16) will be automatically installed. You can check the COM port number in Device Manager of your computer:

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        // Your code here
    

Step 2. Set up Arduino IDE

From version 1.6.5, Arduino IDE supports third-party hardware. Therefore, we can use Arduino IDE to develop applications on RTL8720DN (BW16), and the basic examples of Arduino can run on RTL8720DN (BW16) too. Refer to the basic example link.

Arduino IDE can be downloaded in the Arduino website:

https://www.arduino.cc/en/Main/Software

When the installation is finished, open Arduino IDE. To set up RTL8720DN (BW16) correctly in Arduino IDE, go to “File” -> “Preferences”. 

And paste the following URL into the “Additional Boards Manager URLs” field: https://github.com/ambiot/ambd_arduino/raw/master/Arduino_package/package_realtek.com_amebad_index.json RTL8720DN (BW16) will be supported from v3.0.8 officially.

Next, go to “Tools” -> “Board” -> “Boards Manager”:

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The “Boards Manager” requires about 10~20 seconds to refresh all hardware files (if the network is in bad condition, it may take longer). Every time the new hardware is connected, we need to reopen the Board Manager. So, we close the Boards Manager, and then open it again. Find “Realtek AmebaD Boards (32-bits ARM Cortex-M4 @200MHz)” in the list, click “Install”, then the Arduino IDE starts to download required files for AmebaD.

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If you are facing GitHub downloading issue, please refer to the following link at “Download/Software Development Kit”. There are 3 sections.

1. “AmebaD_Arduino_patch1_SDK”, please select at least 1 of the SDKs. There are 5 latest released SDK options.

2. “AmebaD_Arduino_patch2_Tools”, please select according to your operating system. There are Windows, Linux, and macOS.

3. “AmebaD_Arduino_Source_Code”, this section is an optional download only wants to refer to the latest source code.

https://www.amebaiot.com.cn/en/ameba-arduino-summary/

Download the files selected, then unzip (patch1 and patch2 are compulsory). There are “Install.doc”/“Install.pdf” for you to refer to installation steps. According to your system, please run the installation tool in the “Offline_SDK_installation_tool” folder.

After the installation tool running successfully, you may open Arduino IDE and proceed to “tools” -> “Board“ -> “Boards Manager…”. Try to find “Realtek AmebaD Boards (32-bits ARM Cortex-M4 @200MHz)” in the list, click “Install”, then the Arduino IDE starts to download the required files for AmebaD.

Finally, we select AmebaD as current connected board in “tools” -> “Board” -> “Ameba ARM (32-bits) Boards” ->” RTL8720DN(BW16)”:

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Try the First Example

Step 1. Compile & Upload

Arduino IDE provides many built-in examples, which can be compiled, uploaded, and run directly on the boards. Here, we take the “Blink” example as the first try.

Open “File” -> “Examples” -> “01.Basics” -> “Blink”:

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Arduino IDE opens a new window with the complete sample code.

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There is an onboard LED of RTL8720DN(BW16), the default “LED_BUILTIN” is a green onboard LED. Change “LED_BUILTIN” to “LED_BUILTIN_B” or “LED_BUILTIN_R” for different colors blue and red. Here we use LED_BUILTIN_B as an example.

Next, we compile the sample code directly; click “Sketch” -> “Verify/Compile”:

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Arduino IDE prints the compiling messages in the bottom area of the IDE window. When the compilation is finished, you will get a message similar to the following figure:

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Afterward, we will upload the compiled code to RTL8720DN(BW16).

Please make sure RTL8720DN(BW16) is connected to your computer, then click “Sketch” -> “Upload”.

The Arduino IDE will compile first then upload. During the uploading process, users are required to enter the upload mode of the board. Arduino IDE will wait for 5s for the development board to enter the upload mode.

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To enter the upload mode, first press and hold the RTL8720DN(BW16) "Burn" button, press the "RST" button, and then release the "Burn" button. Press "Upload" to compile and upload the program.

Again, during the uploading procedure the IDE prints messages. The uploading procedure takes a considerably longer time (about 30 seconds to 1 minute). When the upload is completed, the “Upload Image done” message is printed.

Step2. Run the Blink example

In each example, Arduino not only provides sample code but also detailed documentation, including wiring diagram, sample code explanation, technical details, …etc. These examples can be directly used on RTL8720DN (BW16).

So, we find the detailed information of the Blink example in the link below: https://www.arduino.cc/en/Tutorial/BuiltInExamples/Blink

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In short, for RTL8720DN, the example can be run on both the onboard RGB LED or external LED (use any GPIO pins for signal output). Finally, press the “RST” button, and you can see the blue LED blinking.

If you encounter any problem, please refer to Troubleshooting Guide

References

For more information, please visit the following websites:

Since RTL8720DN BW16 is not officially supported by Realtek, alternatively. If you want to know more about our AmebaD Family (RTL8722DM & RTL8722DM-MINI) and ambd_arduino opensource SDK, please also visit:

Qi Zhu