This version (23 Jan 2018 16:32) was approved by Brandon Bushey.The Previously approved version (22 Jan 2018 08:47) is available.
Table of Contents
Acceleration Measurement Demo using the Arduino Uno
The ADXL362_example is an acceleration measurement demo project for the Arduino Uno base board with additional EVAL-ADXL362-ARDZ shield, created using the Arduino IDE.
General Description/Overview
The ADXL362_example uses the EVAL-ADXL362-ARDZ shield which has an ADXL362 3-axis MEMS accelerometer and a incorporated NHD-C12832A1Z-NSW-BBW display (128×32).
The application reads the X , Y , and Z acceleration registers each 500 [ms]. The acceleration in the 3 axes is displayed in [mG] on the LCD. Also this application demonstrates the usage of the motion switch. Movement zones - UP, DOWN, RIGHT, LEFT, CENTER - are displayed in the right side of the LCD.
The EVAL-ADXL362-ARDZ shield provide an internal temperature sensor as an additional features which is read in the same software loop. The value is displayed in ADC codes or in Celsius degrees. The temperature Treal is derived from the ADC readings Tadc using the predefined formula:
Treal = (Tadc + ACC_TEMP_BIAS)/(1 / ACC_TEMP_SENSITIVITY)
Each ADXL362 chip requires individual calibration which can be done by setting the definitions ACC_TEMP_BIAS and ACC_TEMP_SENSITIVITY parameters. Once the ADXL362 chip is calibrated, the software can be changed to display the actual temperature by selecting to display the temperature in degrees.
The software puts the LCD in a “sleep” mode after 10 sec if no movement of the boards is present. The system “wakes-up” if the acceleration on any axes is greater than 50 [mG]. The threshold values can be adjusted by the user.
The acceleration axes, the temperature values and the motion grid are displayed as is presented in the picture on the right.
Demo Requirements
The following is a list of items needed in order to replicate this demo.
- Hardware
- Arduino Uno Rev 3
- EVAL-ADXL362-ARDZ
- Type B to Type A USB cable
- PC or Laptop with a USB port
- Software
- ADXL362_example sketch
- Arduino Interactive Development Environment(IDE)
Setting up the Hardware
- Plug the EVAL-ADXL362-ARDZ shield on top of the Arduino Uno development board by matching up the POWER, ANALOG, DIGI0, DIGI1 connectors.
- Note, the boards should only plug together one way, preventing reverse connections.
- Set the jumpers on the EVAL-ADXL362-ARDZ shield as shown in the next figure.
- Plug in the Type B USB cable into the USB port on the Arduino Uno, and the other end into the PC or laptop.
Obtaining the Source Code
The source code and include files of the ADXL362_example can be found here:
Project Structure
The Arduino Sketch is used to load the example into Arduino IDE. The project is composed of three main parts:
- the main program (arduino sketch)
- application layer (IC drivers and sensor data)
- communication layer
Configuring the Software Parameters
Configure the temperature units in the ADXL362.h file.
#define TEMP_ADC 1 /* 1 for ADC units or 0 for Celsius degrees */
Configure the ADXL362 Calibration Values in the ADXL362.h file. These values will vary from sensor to sensor, but these are typical values from the datasheet.
#define ACC_TEMP_BIAS (float)350 #define ACC_TEMP_SENSITIVITY (float)0.065
Set the Accelerometer Scan Time in the ADXL362.h file. This is how often you read your axis and temperature data.(in ms)
#define SCAN_SENSOR_TIME 500
Set the activity and inactivity thresholds for the ADXL362 in the ADXL362.h file. These values are used to determine which acceleration values the sensor can react at sleep/wake-up commands.(in mG)
#define ACT_VALUE 50 #define INACT_VALUE 50
Set the activity and inactivity time for the ADXL362 in the ADXL362.h file. These values are used to determine sleep/wake-up intervals.(in ms)
#define ACT_TIMER 50 #define INACT_TIMER 50
Configure the Chip Select(CS) Pin for the ADXL362 in the Communication.h file. Position of P9 header
#define ADXL_CS_SEL CSACC_PIN_P0_4 /* CSACC_PIN_P0_3 or CSACC_PIN_P0_4 */
Configure the Interrupt Pin from the ADXL362 in the Communication.h file. Position of P7 header
#define ADXL_INT_SEL INTACC_PIN_1 /* INTACC_PIN_1 or INTACC_PIN_2 */
Configure the Chip Select(CS) Pin for the LCD Screen in the Communication.h file. Position of P8 header
#define LCD_CS_SEL CSLCD_PIN_P1_4 /* CSLCD_PIN_P2_2 or CSLCD_PIN_P1_4 */
Configure the Reset Pin from the LCD Screen in the Communication.h file. Position of P6 header
#define LDC_RST_SEL RSLCD_PIN_IOREF /* RSLCD_PIN_IOREF or RSLCD_PIN_P1_1 */
Compiling, Verifying, and Programming
- Once the project has been imported and the software parameters have been appropriately configured, you must Compile/Verify the project within the Arduino IDE. You can do this by clicking on the Sketch menu, and then on the Compile/Verify option.
- Once the project is compiled and free of errors, you can now upload the project to the Arduino Uno. Click on the Sketch menu item, and then click Upload.
These two steps can also be done using the quick buttons on the Arduino sketch. Check out the image below for locations of the quick buttons.
Outputting Data
Data is output using the USB cable from the Arduino to the PC. The USB port acts as a serial terminal to display the data being transmitted via UART. Opening the serial terminal window from the Arduino IDE is very easy, simply click on the button shown in the picture below.
Serial Terminal Output
You may need to configure the serial terminal depending on the current settings of the Arduino IDE. Make sure the settings are as follows:
Select COM Port Baud rate: 9600 Data: 8 bit Parity: none Stop: 1 bit Flow Control: none
Tools Download and Help
The Arduino tools are easy to use, and there are many tutorials and users guides to help learn how to use the Arduino IDE.
For more information on how to use the tool basics, please check out the Arduino tutorials page.
To download the Arduino tools, check out the Arduino software page.
End of Document
resources/eval/user-guides/arduino-uno/reference_designs/demo_adxl362.txt · Last modified: 23 Jan 2018 16:25 by Mircea Caprioru