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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.
HW Platform(s):
System: Microblaze, AXI, UART
The bit file provided in the project *.zip file combines the FPGA bit file and the SDK elf files. It may be used for a quick check on the system. All you need is the hardware and a PC running a UART terminal and the programmer (IMPACT).
If you are not familiar with LX9 and/or Xilix tools, please visit
http://www.xilinx.com/products/boards-and-kits/AES-S6MB-LX9.htm for details.
If you are not familiar with Nexys™3 and/or Xilix tools, please visit
http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,400,897&Prod=NEXYS3 for details.
Extract the project from the archive file (ADXL362_<board_name>.zip) to the location you desire.
To begin, connect the PmodACL2 to J5 connector of LX9 board (see image below). You can use an extension cable for ease of use. Connect the USB cables from the PC to the board.
To begin, connect the PmodACL2 to JA connector of NEXYS3 board (see image below). You can use an extension cable for ease of use. Connect the USB cables from the PC to the board.
Start IMPACT, and double click “Boundary Scan”. Right click and select Initialize Chain. The program should recognize the Spartan 6 device (see screenshot below). Start a UART terminal (set to appropiate baud rate) and then program the device using the bit file provided in the project *.zip archive, located in the “sw” folder (../adxl362/sw/ADXL362.bit).
If programming was successful, the Main Menu will apear in your UART terminal, as seen in the picture below. There are 7 options. Pressing [1] to [5], [s] or [r] key will allow you to select the desired option.
Display acceleration on All Axes will print the acceleration on X, Y and Z Axes, each on a separate row.
Display acceleration on X Axis will print the acceleration on X Axis, each new data read from the device will be displayed on a separate row.
Display acceleration on Y Axis will print the acceleration on Y Axis, each new data read from the device will be displayed on a separate row.
Display acceleration on Z Axis will print the acceleration on Z Axis, each new data read from the device will be displayed on a separate row.
Display temperature will print the ADXL362 temperature in Celsius Degrees.
Select range will allow setting the measurement range of the ADXL362. You can choose between ±2g, ±4g and ±8g. Selecting the desired range is done by pressing [1] to [3].
Switch resolution option is used to choose reading data from 8 bit register or from 12 bit register.
The reference design is a SPI interface used to communicate with the device. The software programs the ADXL362s internal registers, and afterwards reads desired data from the device and prints it via UART.