Analog Devices ADXL202 2-Axis 2g Acceleration Sensor

© Brooke Clarke 2000 - 2007

There is now a Analog Devices XL330 3-axis accelerometer. very low power & easy to interface.

see thePIC based G-Pendent web page for more.

J1 Com Connector to supplied Cable

1    Power In -6 to -12 unregulated from computer RTS
2    Xmit Data to computer
3    Rec Data from computer
4    not used

J2 - Secondary Connector- Analog & PWM signals

1    Power In -6 to -12 Vdc
2    XFILT
3    YFILT
4    Xout
5    Yout
6    Ground

J3

1    ADXL202 pin3 - Self Test - connecting to Vdd causes a 0.8g acceleration
2    Vdd

R1

the holes for R1 are in parallel with the surface mount R6 (62.1k for 2 kHz sample rate).

X CAP & Y CAP

There are through holes for XCAP and YCAP in parallel with surface mount capacitors C15 and C11 (set for 106 Hz filter cutoff).

X1 & X2 -?

a pattern of 3, 4, 3, 4 (total of 14 holes) with an outline like a battery - ?

Software

Labview 202demo.vi

This program has the Labview source code.The 202demo.vi program did not find the "Serial Read with Timeout.vi".  It is located in:
program files\National Instruments/Labview51/EXAMPLES/instr/smplserl.llb

X-Analize

This program has three display modes, scren dumps shown below:

• Front Panel
• Graph
• FFT Spectrum Analysis
• Bubble Level & Pitch-Roll

There is a choice of EB202-RS232 or EB202-RS232-A. i.e. there is now an "A" version.

Documentation

The CD-ROM has the following structure:

• Document
• 202decod.pdf - the app note on decoding the PWM utput
• 202embed.pdf - the app note on embedding temperature with the PWM output
• Accel.pdf - a sales presenation on the AD line of accelerometers and their apps
• car_app.pdf - a car alarm example
• Eb232-a1 - "A" version eval board operating instructions
• Installa (First 8 characters of Installation)
• setup program to install the X-Analyze and LabVIEW programs
• Sub folder with the LabVIEW51 runtime only software (I am using the Developers version of LV5.1)
• Software
• 202demo.vi - with the missing "Serial Read with Timeout.vi"
• Ad202Eb.asm - PIC16C63A assembly source file - can use with the free MPLAB from Microchip. Unfortunatly they used a surface mount 16C63A. It would have been much nicer if it was a socketed part. The lead pitch on a socketed part is 0.1" but on the surface mount part it is 0.05" so it is not easy to remove the existing part and add a socket.  But I will be looking into how to get a socket connected so that I can burn my own 16C63A parts using the Pickstart+ from Microchip Technology.
• Websites
• http://www.analog.com/iMEMS/products/ADXL202_top.html
• http://www.analog.com/iMEMS/
• http://www.xbow.com/