1. Introduction
This is a quick start guide through the fundamentals of Multisensor InerTial CHamaleon (MITCH) platform.
2. System Description
Mitch is a low power, state-of-the-art scalable inertial data acquisition platform that can be expanded with different sensing peripherals making it suitable for a wide range of applications. Mitch can measure accelerations, angular rate, and magnetic field. Furthermore, it supports also the use of plug-and-play sensors such as Force-Sensing Resistor (FSR) membranes (i.e., up to 16-channels), proximity sensors (i.e., Time Of Flight – TOF), Hearth Rate (HR) and pulse-oximetry (PPG).
Mitch includes wireless connectivity, automated on/off functions, and regulated rechargeable power. It’s a fully certified, safe, production and professional research platform for wearable and connected industrial use cases.
FIGURE 1: MITCH.
3. Power On/Off
- To Power On the device, hold pressed the button, located on side of the device near to the USB connector, for at least 4 seconds. The blue LED indicator starts blinking and the system is ready.
- To Power Off the device, hold pressed the button until the blue LED indicator goes off.
- If properly configured (i.e., mode and frequency), the smart button allows also to control the data acquisition in log mode.
4. Recharge Battery
To recharge the battery, connect the USB cable. The green LED indicator breaths when recharging. When fully charged, the green LED indicator stop breathing.
Mitch uses a rechargeable lithium-polymer battery and includes circuitry for both thermal and electrical protection against over-voltage and over-current conditions. As with any lithium-polymer battery-powered device, the following should be observed:
- do not disassemble, crush, puncture, shred the battery
- do not let the battery to get in contact with water or other liquid
- do not short the battery contacts to metal objects
- do not place the battery near thermal heat sources.
5. Operating Mode
Mitch can operate in 2 modes:
-
Streaming
It allows for managing a continuous data stream to a master application typically running on desktop or mobile platforms. It requires a stable BLE connection. -
Log
It allows for data log into the external flash memory integrated on device.
It can be controlled using BLE connection or smart button, if properly configured.
In both modes, the system can be powered by battery or by cable, typically micro–USB Type-B. It is worth noting that the battery must always be connected to the device. It cannot operate wired, without battery.
7. Compliance and Warning
Mitch implements a Right-Handed coordinate system, where the x-axis is outgoing with respect to the USB, while z-axis is outgoing from top of the board. Each rotation is clockwise positive with respect to the relative axis.
FIGURE 2: MITCH PLATFORM WITH ITS REFERENCE SYSTEM. X (RED), Y (GREEN), Z (BLUE) AXES.
Magnetic distortions (e.g., proximity to metal objects or electromagnetic fields) can affect the accuracy of the heading estimation.
Mitch is supplied with the following default configuration. It is always recommended to perform a calibration of the magnetometer to setup the overall system to the environmental conditions of use.
Gyroscope full scale | 2000 dps |
Accelerometer full scale | 16 g |
Magnetometer full scale | 50 G |
Log mode | 9 DOF (i.e., gyr / axl / mag) |
Log frequency | 200 Hz |
To customize Mitch settings run Mitch viewer software application and connect the device.