RTL8722DM_mini_Arduino SDK_getting start.rst

Getting Started

Required Environment

AmebaD RTL8722DM_MINI currently supports Windows XP/7/8/10 32-bits and 64-bits, Linux and Mac operating systems. In this documentation, please use Arduino IDE with version 1.8.12 or later.

Introduction to AmebaD RTL8722DM_MINI

Ameba is an easy-to-program platform for developing all kind of IoT applications. AmebaD is equipped with various peripheral interfaces, including WiFi, GPIO INT, I2C, UART, SPI, PWM, ADC. Through these interfaces, AmebaD can connect with electronic components such as LED, switches, manometer, hygrometer, PM2.5 dust sensors, …etc.

The collected data can be uploaded via WiFi and be utilized by applications on smart devices to realize IoT implementation.

RTL8722DM_MINI has smaller size than Arduino Uno, as shown in the above figure.

RTL8722DM_MINI 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 RTL8722DM_MINI.

D0	GPIOB_0	✓					I2C0 SDA
D1	GPIOB_1	✓	A4		Serial2_TX
D2	GPIOB_2	✓	A5		Serial2_RX
D3	GPIOB_3	✓	A6
D4	GPIOB_4	✓	A0	✓
D5	GPIOB_5	✓	A1	✓			I2C0 SCL
D6	GPIOB_6	✓	A2				I2C0 SDA
D7	GPIOB_7	✓	A3	✓
D8	GPIOA_2	✓
D9	GPIOA_12	✓		✓	Serial2_TX	SPI1_MOSI
D10	GPIOA_13	✓		✓	Serial2_RX	SPI1_MISO
D11	GPIOA_14	✓				SPI1_CLK
D12	GPIOA_15	✓				SPI1_CS
D13	GPIOA_16	✓
D14	GPIOA_28	✓		✓
D15	GPIOA_18	✓			Serial1_TX
D16	GPIOA_19	✓			Serial1_RX
D17	GPIOA_30	✓		✓
D18	GPIOA_21	✓			Serial1_TX
D19	GPIOA_22	✓			Serial1_RX
D20	GPIOA_23	✓		✓
D21	GPIOA_24	✓		✓
D22	GPIOA_31	✓					I2C0 SCL

Setting up Development Environment

Step 1. Installing the Driver

First, connect RTL8722DM_MINI to the computer via Micro USB(same as power):

If this is the first time you connect RTL8722DM_MINI to your computer, the USB driver for RTL8722DM_MINI will be automatic installed.

You can check the COM port number in Device Manager of your computer:

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 RTL8722DM_MINI, and the examples of Arduino can run on RTL8722DM_MINI too. Refer to 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 RTL8722DM_MINI correctly in Arduino IDE, go to “File” -> “Preferences”.

And paste the following URL into “Additional Boards Manager URLs” field: https://github.com/ambiot/ambd_arduino/raw/master/Arduino_package/package_realtek.com_amebad_index.json

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

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.

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 operation system. There are Windows, Linux and MacOS.

3. “AmebaD_Arduino_Source_Code”, this section is optional download only wants to refer 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 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 required files for AmebaD.

Finally, we select AmebaD as current connected board in “tools” -> “Board” -> “Ameba ARM (32-bits) Boards” ->” RTL8722DM_MINI”：

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”:

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

There are onboard LED of TRL8722DM_MINI, the default “LED_BUILTIN” is blue onboard LE.D

Change “LED_BUILTIN” to “LED_B” or “LED_G” for different colour. Onboard LEDs options LED_B and LED_G. (blue and green).

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

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

Afterwards, we will upload the compiled code to RTL8722DM_MINI.

Please make sure RTL8722DM_MINI 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 5s for DEV board to enter the upload mode.

To enter the upload mode, first press and hold the UART_DOWNLOAD button, then press the RESET button. If success, you should see the onboard green LED and blue LED all turned off.

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

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 RTL8722DM_MINI.

So, we find the detailed information of the Blink example:

https://www.arduino.cc/en/Tutorial/BuiltInExamples/Blink

In short, for RTL8722DM_MINI, the example can be run on both onboard LEDs (green or blue) or external LED (use any GPIO pins for signal output).

Finally, press the RESET button, and you can see the LED blinking.

If you encounter any problem, please refer to Troubleshooting.