3-Channel Neopixel Board for the Mercury System

• User LED: by default it is set to work in heartbeat LED mode (periodic pulses).
• Mercury Connector: used to interface with the other boards of the Mercury system.
• Address Dip Switch: to set the board address within the Mercury system.
• Programmer Connector: PicKit 3 Microchip programmer/debugger connector. It plugs straight into the microcontroller debug port to allow advanced debugging and programming.
• Power Source Sel. Jumper: Jumper for choosing the power source for the Neopixel channels: internal (VddBat) or external.

• Timer: 4 x 8-bit, 1 x 16-bit
• ADC: 12 ch, 10-bit
• Comparators: 2
• Temperature range: -40°C ~ 125°C
• Operating voltage: 1.8~5.5 V
• Pin Count: 20
• XLP: yes

The set of boards that makes up the Mercury System is organised into 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 carries a simple power supply and a charging unit for a single LiPo cell (enough to meet the power needs of simpler systems). It can exist in several variants, depending on the microcontroller unit used.

• Modem Board (MB): this is the board that provides network connectivity. It can exist in several variants, depending on the network interface (GSM / GPRS, Wi-Fi, BT, Radio and so on). 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 there are any. They can vary according to the specific energy requirement to be met (high power, solar harvesting, piezoelectric harvesting and so on).

• Slave Board (SB): these are the peripherals of the system, and they vary according to the specific sensor or actuator fitted. Typical examples are SBs with relays, temperature sensors, RGB LED controllers, servo drivers and accelerometers. 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 in a plane. There are variants that can carry displays, a battery holder and so on.

• 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 a Firmware that implements a dedicated command set for high-level management, while the Base Boards carry a Software framework that provides all the low-level services (operating system, peripheral drivers, system services and so on), leaving the user only the application-level logic to develop.

HAL (Hardware Abstraction Layer): the purpose of this layer is to abstract the Hardware dependencies away 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 and so on.
It is split into two main components:

• PML: peripheral management layer
• SSL: system services layer

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

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 a few examples for each sub-family:

• Mercury System Getting Started Guide IoT and Connectivity Made Simple
• Slave FW Upgrade Package
• FW Package
• MS_SB120_Datasheet
• MS_SB120_Schematic