world leader in high performance signal processing
This version (04 Jul 2013 09:35) was approved by DragosB.The Previously approved version (09 Oct 2012 09:19) is available.Diff

ADXL362 - No-OS Driver for Microchip Microcontroller Platforms

Supported Devices

Evaluation Boards

Overview

The ADXL362 is an ultralow power, 3-axis MEMS accelerometer that consumes less than 2 μA at a 100 Hz output data rate and 270 nA when in motion triggered wake-up mode. Unlike accelerometers that use power duty cycling to achieve low power consumption, the ADXL362 does not alias input signals by undersampling; it samples the full bandwidth of the sensor at all data rates.

The ADXL362 always provides 12-bit output resolution; 8-bit formatted data is also provided for more efficient single-byte transfers when a lower resolution is sufficient. Measurement ranges of ±2 g, ±4 g, and ±8 g are available, with a resolution of 1 mg/LSB on the ±2 g range. For applications where a noise level lower than the normal 550 μg/√Hz of the ADXL362 is desired, either of two lower noise modes (down to 175 μg/√Hz typical) can be selected at minimal increase in supply current.

In addition to its ultralow power consumption, the ADXL362 has many features to enable true system level power reduction. It includes a deep multimode output FIFO, a built-in micropower temperature sensor, and several activity detection modes including adjustable threshold sleep and wake-up operation that can run as low as 270 nA at a 6 Hz (approximate) measurement rate. A pin output is provided to directly control an external switch when activity is detected, if desired. In addition, the ADXL362 has provisions for external control of sampling time and/or an external clock.

The ADXL362 operates on a wide 1.6 V to 3.5 V supply range, and can interface, if necessary, to a host operating on a separate, lower supply voltage. ADXL362 is available in a 3 mm × 3.25 mm × 1.06 mm package.

Applications

  • Hearing aids
  • Home healthcare devices
  • Motion enabled power save switches
  • Wireless sensors
  • Motion enabled metering devices

01 Oct 2012 11:49 · Dragos Bogdan

The goal of this project (Microcontroller No-OS) is to be able to provide reference projects for lower end processors, which can't run Linux, or aren't running a specific operating system, to help those customers using microcontrollers with ADI parts. Here you can find a generic driver which can be used as a base for any microcontroller platform and also specific drivers for different microcontroller platforms.

Driver Description

The driver contains two parts:

  • The driver for the ADXL362 part, which may be used, without modifications, with any microcontroller.
  • The Communication Driver, where the specific communication functions for the desired type of processor and communication protocol have to be implemented. This driver implements the communication with the device and hides the actual details of the communication protocol to the ADI driver.

The Communication Driver has a standard interface, so the ADXL362 driver can be used exactly as it is provided.

There are three functions which are called by the ADXL362 driver:

  • SPI_Init() – initializes the communication peripheral.
  • SPI_Write() – writes data to the device.
  • SPI_Read() – reads data from the device.

SPI driver architecture

The following functions are implemented in this version of ADXL362 driver:

Function Description
char ADXL362_Init(void) Initializes the device.
void ADXL362_SetRegisterValue(unsigned short registerValue, unsigned char registerAddress, unsigned char bytesNumber) Writes data into a register.
void ADXL362_GetRegisterValue(unsigned char *pReadData, unsigned char registerAddress, unsigned char bytesNumber) Performs a burst read of a specified number of registers.
void ADXL362_GetFifoValue(unsigned char *pBuffer, unsigned short bytesNumber) Reads multiple bytes from the device's FIFO buffer.
void ADXL362_SoftwareReset(void) Resets the device via SPI communication bus.
void ADXL362_SetPowerMode(unsigned char pwrMode) Places the device into standby/measure mode.
void ADXL362_SetRange(unsigned char gRange) Selects the measurement range.
void ADXL362_SetOutputRate(unsigned char outRate) Selects the Output Data Rate of the device.
void ADXL362_GetXyz(short *x, short *y, short *z) Reads the 3-axis raw data from the accelerometer.
void ADXL362_GetGxyz(float* x, float* y, float* z) Reads the 3-axis raw data from the accelerometer and converts it to g.
float ADXL362_ReadTemperature(void) Reads the temperature of the device.
void ADXL362_FifoSetup(unsigned char mode, unsigned short waterMarkLvl, unsigned char enTempRead) Configures the FIFO feature.
void ADXL362_SetupActivityDetection(unsigned char refOrAbs, unsigned short threshold, unsigned char time) Configures activity detection.
void ADXL362_SetupInactivityDetection(unsigned char refOrAbs, unsigned short threshold, unsigned short time) Configures inactivity detection.
01 Oct 2012 15:23 · Dragos Bogdan

Downloads

Digilent Cerebot MX3cK Quick Start Guide

This section contains a description of the steps required to run the ADXL362 demonstration project on a Digilent Cerebot MX3cK platform.

Required Hardware

Required Software

The ADXL362 demonstration project for PIC32MX320F128H consists of three parts: the ADXL362 Driver, the PmodACL2 Demo for PIC32MX320F128H and the PIC32MX320F128H Common Drivers.

All three parts have to be downloaded.

Hardware Setup

A PmodACL2 has to be connected to the JE connector of Cerebot MX3cK development board.

Reference Project Overview

The following commands were implemented in this version of ADXL362 reference project for Cerebot MX3cK board.

Command Description
help? Displays all available commands.
id? Displays device details.
measure= Start/stop the measurement process of the device. Accepted values:
0 - Stop measurement.
1 - Start measurement.
temperature? Displays the temperature.
reset! Resets the device.
acceleration? Displays the accelerations on XYZ axes.
accelerationX? Displays the acceleration on X axis.
accelerationY? Displays the acceleration on Y axis.
accelerationZ? Displays the acceleration on Z axis.
activity? Displays the activity status of the device. It runs for 5 motion detections.

Commands can be executed using a serial terminal connected to the UART1 peripheral of PIC32MX320F128H.

The following image shows a generic list of commands in a serial terminal connected to processor’s UART peripheral.

Software Project Setup

This section presents the steps for developing a software application that will run on the Digilent Cerebot MX3cK development board for controlling and monitoring the operation of the ADI part.

  • Run the MPLAB X integrated development environment.
  • Choose to create a new project.
  • In the Choose Project window select Microchip Embedded category, Standalone Project and press Next.

  • In the Select Device window choose PIC32MX320F128H device and press Next.

  • In the Select Tool window select the desired hardware tool and press Next.

  • In the Select Compiler window chose the XC32 compiler and press Next.

  • In the Select Project Name and Folder window choose a name and a location for the project.

  • After the project is created, all the downloaded source files have to be copied in the project folder and included in the project.

  • The project is ready to be built and downloaded on the development board.

05 Jul 2012 14:45

Digilent Cerebot MC7 Quick Start Guide

This section contains a description of the steps required to run the ADXL362 demonstration project on a Digilent Cerebot MC7 platform.

Required Hardware

Required Software

Hardware Setup

A PmodACL2 can be connected to the JB connector of Cerebot MC7 development board for SPI operation,

Reference Project Overview

Following commands were implemented in this version of ADXL362 reference project for Cerebot MC7 board.

Command Description
help? Displays all available commands.
id? Device details.
measure= Start/stop the measure process of the device. Accepted values: 0 - 1.
temp? Read the temperature.
reset= Reset the device.
acceleration? Displays the accelerations on XYZ axis.
activity? Displays the activity status of the device. It runs for 5 motion detections.

Commands can be executed using a serial terminal connected to the UART1 peripheral of dsPIC33FJ128MC706A.

The following image shows a list of commands in a serial terminal connected to processor’s UART peripheral.

Software Project Setup

This section presents the steps for developing a software application that will run on the Digilent Cerebot MC7 development board for controlling and monitoring the operation of the ADI part.

  • Run the MPLAB X integrated development environment.
  • Choose to create a new project.
  • In the Choose Project window select Microchip Embedded category, Standalone Project and press Next.

  • In the Select Device window choose dsPIC33FJ128MC706A device and press Next.

  • In the Select Tool window select the desired hardware tool and press Next.

  • In the Select Compiler window chose the XC16 compiler and press Next.

  • In the Select Project Name and Folder window choose a name and a location for the project.

  • After the project is created, the source files have to be copied in the project folder and included in the project.

  • The project is ready to be built and downloaded on the development board.

16 Jul 2012 16:48

Digilent Cerebot MX3cK Quick Start Guide - chipKIT Project

This section contains a description of the steps required to run the ADXL362 chipKIT demonstration project on a Digilent Cerebot MX3cK platform.

Required Hardware

Required Software

Hardware Setup

A PmodACL2 has to be connected to the JE connector of Cerebot MX3cK development board.

Reference Project Overview

Following commands were implemented in this version of ADXL362 chipKIT reference project for Cerebot MX3cK board.

Command Description
help? Displays all available commands.
id? Device details.
measure= Start/stop the measure process of the device. Accepted values: 0 - 1.
temp? Read the temperature.
reset= Reset the device.
acceleration? Displays the accelerations on XYZ axis.
activity? Displays the activity status of the device. It runs for 5 motion detections.

Commands can be executed using the serial monitor.

Carriage return has to be selected as a line ending character. The required baud rate is 9600 baud.

The following image shows a list of commands in the serial monitor.

Software Project Setup

This section presents the steps for developing a chipKIT application that will run on the Digilent Cerebot MX3cK development board for controlling and monitoring the operation of the ADI part.

  • Under your Sketchbook directory create a folder called “Libraries”; this folder may already exist.
  • Unzip the downloaded file in the libraries folder.
  • Run the MPIDE environment.
  • You should see the new library under Sketch→Import Library, under Contributed.

  • Also you should see under File→Examples the demo project for the ADI library.
  • Select the ADIDriver example.

  • Select the Cerebot MX3cK board from Tools→Board.
  • Select the corresponding Serial Communication Port from Tools→Serial Port
  • The project is ready to be uploaded on the development board.

23 Jul 2012 16:51

More information