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Anleitung Zusammenfassung
Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • iMEMS ADXL345 Inertial Sensor Datalogger and Development Board FEATURES Ultralow power ADXL345 accelerometer Inertial sensor development board Datalogs onto MicroSD card Fully programmable via serial interface; firmware examples provided Battery-powered for portable applications REQUIREMENTS 2 AAA batteries MicroSD card and card reader (for datalogging) Computer with serial port (for programming) Figure1.InertialSensorDevelopmentBoard 08658-001 GENERAL DESCRIPTION It is often a time saver in hardware development to make progress on the firmware and the hardware simultaneously. The challenge is that it proves difficult to develop firmware before the hardware exists. The iMEMS® ADXL345 development board is an easy- to-use tool that facilitates prototyping by providing a platform that can be duplicated in the final application. Additionally, the development board can be configured as a datalogger and can be used to gather data for refining algorithms, tuning thresholds, and generally familiarizing oneself with accelerometer data. Two AAA batteries power the development board and thus it integrates seamlessly into portable applications. Communications and processing is done by an ARM7-based ADuC7024 micro- controller, and the interface provided is fully reprogrammable. Moreover, all ADuC7024 pins are broken out into headers to facilitate design of compatible expansion boards. Data is logged onto a MicroSD memory card, providing essentially unlimited memory capacity and operating system versatility. Data is stored in a text file; therefore, there is no need to install any software to operate the board or read data. Software is provided to assist with programming the board. Please see the last page for an important warning and disclaimers. Rev.0|Page 1of8 UG-065 Evaluation Board User Guide TABLE OF CONTENTS Features .............................................................................................. 1 Requirements .................................................................................... 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Overview............................................................................................ 3 Features .......................................................................................... 3 Using the Board ................................................................................ 4 REVISION HISTORY 2/10—Revision 0: Initial Revision Getting Started...............................................................................4 Programming the Board...............................................................4 Software Tools................................................................................4 Board Layout and Schematics..........................................................6 ESD Caution...................................................................................8 Rev.0|Page 2of8 Evaluation Board User Guide UG-065 OVERVIEW The ADXL345 inertial sensor development board has the following features: • A 2-layer printed circuit board (PCB), 1.125-inches . 2.25- inches form factor • A two AAA battery power supply • A 4-pin UART header to connect to RS232 interface cable • Reset/download push-buttons • Power indicator/general-purpose LEDs • Access to all microcontroller I/Os from the external header; all device pins are brought out to the external header pins • Demonstration firmware FEATURES Power Supply A pair of AAA batteries powers the board, and the battery holder is located on the back of the board. An on/off switch on the lower left of the front of the board controls power to it. The battery voltage is not regulated but is decoupled with a 10 .F capacitor globally, and an additional 1 .F capacitor at the device supply pins to ground. RS232 Interface The ADuC7024 (UC1) P1.1 and P1.0 lines are connected to the RS232 interface cable via the connector (UART). The interface cable generates the required level shifting to allow direct connection to a PC serial port. Ensure that the supplied cable is connected to the board correctly, that is, VDD is connected to VDD and GND is connected to GND. RESET/PROG Push-Buttons A RESET push-button is provided to allow the user to manually reset the part. When inserted, the RESET pin of the ADuC7024 is pulled to GND. Because the RESET pin on the ADuC7024 is Schmitt-triggered internally, there is no need to use an external Schmitt trigger on this pin. To enter serial download mode, the user must hold the P0.0/BM pin low while reset is toggled. On the development board, serial download mode can be easily initiated by holding down the serial download push-button (PROG) while inserting and releasing the reset button (RESET), as illustrated in Figure 2....