Hardware

Shimmer wearable wireless sensor platform continues to be built around some key fundamental features. The Shimmer platform is an open source, flexible, and a highly configurable platform, that is designed to capture sensed data to the highest of quality.

Hardware Overview

The image below illustrates a block diagram of the Shimmer baseboard interconnections between and integrated devices.

CPU

The core element of the platform is the low-power MSP430F1611 microprocessor which controls the operation of the device.  Nearly every feature of the CPU is exercised in the Shimmer implementation! The CPU configures and controls various integrated peripherals through I/O pins, some of which are available on the internal/external-expansion connectors.

Shimmer Baseboard Interconnections and Integrated Devices

The CPU has an integrated 8-channel 12bit analog-to-digital converter (ADC) which is used to capture sensor data from the accelerometer, battery, or sensor expansions such as ECG, kinematics, GSR, and EMG. The external expansion allows communication to and from the baseboard using the docking station.

Data Transmission and Storage

For wireless data streaming the platform is equipped with both Bluetooth and 802.15.4 radio modules. The Shimmer board has a built in microSD Flash socket for additional storage.  To improve usability, SHIMMER incorporates components to provide direct and immediate access to microSD flash memory using an external SD-flash card controller (SDHOST) for high-speed data transfer.

Functionality

A push-button power controller powers off the entire board after a held press of the reset button.  Software controlled power switching is provided for both the Bluetooth radio module and microSD socket.  Three light-emitting diodes (LED) are used to display application status.

Finally a tri-axial MEMs accelerator and omni-directional tilt/vibration sensing round out the integrated peripheral suite.