Wi-Fi modem board for the Mercury System

• Power LED: shows the power status of the board.
• Serial Activity LED: shows the activity on the board’s serial line.
• Status LED: shows the status of the board.
• Mercury Modem Connector: the Mercury connector used to interface with the Base Board (BB) of Mercury systems.

• Link: IEEE 802.11 b/g/n Wi-Fi

The set of boards that makes up the Mercury System is organised in the following “families”:

• Base Board (BB): It is the “brain” of the whole Mercury System and holds the main logic unit, several communication buses and the connectors for interfacing the slaves. It also has a simple power supply and a charger for a single LiPo cell (enough to meet the power requirements of simpler systems). It comes in several variants, depending on the microcontroller unit used.

• Modem Board (MB): this is the board that provides network connectivity. It comes in several variants, depending on the network interface (GSM / GPRS, Wi-Fi, BT, Radio …). It is interfaced to the base board over a dedicated serial line.

• Power Board (PB): this is the board that meets the particular energy needs of the system, when they arise. They vary according to the specific energy need to be met (high power, solar harvesting, piezoelectric harvesting, etc.).

• Slave Board (SB): these are the peripherals of the system and vary according to the specific sensor or actuator fitted. Typical examples are SBs with relays, temperature sensors, RGB LED controllers, servo controller, accelerometer, etc. They talk to the BB over I2C or UART with a dedicated command set.

• Expansion Board (EB): these are the boards that allow Mercury boards to be connected side by side on one plane. There are variants that can carry a display, a battery holder, etc.

• Brain-Less Board (BL): these are the boards without a controller. In general they carry really simple sensors or actuators that do not need the bus interface. They are an alternative to the slave boards for applications where cost has to be kept down.

The Slave Boards and the Modem Boards come pre-programmed with firmware that implements a dedicated command set for high-level control, while the Base Boards carry a software framework that provides all the low-level services (operating system, peripheral drivers, system services, etc.), leaving the user with nothing to develop but the application-level logic. 

HAL (Hardware Abstraction Layer): the purpose of this layer is to hide the hardware dependencies from the layers above.
SML (System Management Layer): the purpose of this layer is to provide services for managing the communication buses (I2C, UART) and for managing the Modem Board (WiFi, BT, GSM / GPRS). It also provides a set of system services such as System Power Management, RTCC, USB terminal, etc.
It is split into two main components:

OSL (Operative System Layer): this layer consists of a lightweight RTOS that provides the basic services to the system, such as the scheduling tables for the various tasks, events, SW timers, alarms, etc.

There are several sub-families of Slave Board:

• Sensor Slave Board
• Actuator Slave Board
• Communication Slave Board
• Interface Slave Board
• Special Slave Boards

The table below gives some examples for each sub-family:

• Mercury System Getting Started Guide IoT and Connectivity Made Simple
• MS_MB210_Datasheet
• MS_MB210_Schematic