Realtek RTL8720CM Ameba Z2 AWS IoT ExpressLink DevKit

The board comes pre-flashed with AWS IoT ExpressLink firmware. Connect it to your host microcontroller or PC via a USB-to-UART adapter using the main UART pins (check pinout). Power the board with 3.3V. Use the documented AT command set over this serial connection to provision the device with your AWS credentials (thing name, certificates). The ExpressLink module handles TLS, MQTT connection, and authentication with AWS IoT Core automatically. You can then send and receive data using simple AT+ commands.

The AWS IoT ExpressLink firmware on the Ameba Z2 typically operates at a standard baud rate of 115200 bps (8-N-1). Confirm this in the official Realtek or AWS-provided documentation for the specific firmware version. To configure it, open a serial terminal (like PuTTY or Arduino IDE Serial Monitor) set to 115200 baud. Send the basic AT command to check connectivity. You will then use AT commands like AT+CONF to set Wi-Fi SSID/password, AT+CONNECT to establish the cloud link, and AT+SEND to publish data. Always ensure you are using the correct UART TX/RX GPIO pins on the board.

While the primary use case is as an AWS ExpressLink co-processor via AT commands, the Realtek RTL8720CM SoC is a fully programmable ARM Cortex-M4 microcontroller. Realtek provides the Ameba SDK/development environment for writing and flashing custom firmware directly onto the chip, allowing you to use its Wi-Fi/BLE stack, GPIOs, and peripherals natively. However, doing so will overwrite the pre-installed AWS ExpressLink firmware. For most users, the recommended flow is to use a separate host MCU to send AT commands to the Ameba Z2, treating it as a secure, certified wireless cloud modem.

The Ameba Z2 DevKit operates at a standard 3.3V DC supply. The typical operating current varies significantly based on mode: during deep sleep with radios off, it can draw microamps; during active Wi-Fi transmission at maximum power, it can draw several hundred milliamps. For reliable operation, especially during RF transmission peaks, use a regulated 3.3V power source capable of delivering at least 500mA. Ensure your power supply wiring has minimal voltage drop. The board's power management unit supports various low-power sleep modes accessible via AT commands to optimize battery life in field deployments.