Experiments with the Meross MSS310 Smart Plug

This repository contains code to experiment with the Meross MSS310 smart plug. The plug contains a daughter board with a Mediatek MT7688KN SoC. The device boots into u-boot, which then boots the real application which uses the eCos operating system.

Note: the code assumes hardware revision 1. With hardware revision 2, Meross uses an MT7682SN SoC, which contains an ARM core instead of a MIPS core.

The initial scaffold for the code in this repository has been taken from Nicholas FitzRoy-Dale’s bare-metal hello world. It is used to determine how to run my own software on the device and only serves as proof-of-concept. The real application will get its own repository, some day..., perhaps... .

Running the blink application

• Get a cross compiler for MIPS. Or simply build one yourself using crosstool-ng. Run make. You probably need to change the path to the cross compiler in the Makefile.

• Open the plug and solder four wires to the CPU board (RX, TX, GND, 3V3) and connect an USB-to-serial port to RX, TX and GND. Use your preferred terminal program to connect to the serial port. Parameters are 57600,8N1.

• Do NOT plug the device into a power outlet! Instead, connect an external power-supply, 3.3V capable of delivering 500mA. While the board draws less than 200mA when running, it doesn't boot if the power supply's current limit is set to 200mA.

• Hit 4 immediately when then device boots. This should drop you on the u-boot command line.

• Enter loadb 1000000 in the serial console, then disconnect your terminal.

• From the host's command line, run kermit -s blink.bin to upload the compiled binary.

• Connect to the MSS10 via the terminal program again. The loadb command should have terminated (you might need to hit the Return key). Enter go 1000000 and the LEDs on the device should start cycling through all color combinations. Pressing the button should reboot the device.