bs accelerometer rev1

7/31/2019 BS Accelerometer Rev1

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2. Quick Start

Make Sure you have the following equipment

- BASIC Stamp Module

- Compatible Carrier Board

- Programming Cable (Serial Cable or Serial/USB cable)

- Power Supply

- 80486 or higher PC running Windows

Connect the chip, Data cable, and Power Supply (or Battery) to the Board

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If you dont have a serial port in your computer, you can use a USB to Serial

adapter. (If you have a serial port in your machine, just skip these steps and go

3.Installation and Test of software.)

STEP 1. Installation of drivers

To use this adapter, simply plug it in to

your machine's USB port.

Then, install the drivers. They are

available on the Parallax CD, or can be

downloadable via internet.

http://www.parallax.com/detail.asp?

product_id= 28850 or

http://www.parallax.com/detail.asp?product_id=800-00030

Copy (if using the Parallax CD) orunzip (if downloaded) the driver files to

a temporary folder that is easy to locate on your system. For the purposesof these instructions we will use the folder: C:\temp\FTDI

Plug the USB device into your system. A "Found New Hardware" message

should appear, followed by the Found New Hardware Wizard dialog.

Select install from a list or specific location(advanced), click on the

Next button.

Select "Search for the best driver in these locations," (1) mark the

checkbox next to "Include this location in the search:" and enterthe path,

C:\temp\FTDI, or (2) click the browse button to find the folder

When the installation is complete, you will see a dialog. Click on theFinish button.

STEP 2: USB COM Port Identification

Click on "Start" button

Click on "Control Panel"

Double-click on "System" icon

Click on "Hardware" tab

Click on "Device Manager" button

Expand "Ports (COM & LPT)" tree by clicking on the [+] icon

PDI Studio V 3
http://www.parallax.com/detail.asp?product_id=28850http://www.parallax.com/detail.asp?product_id=28850http://www.parallax.com/detail.asp?product_id=800-00030http://www.parallax.com/detail.asp?product_id=28850http://www.parallax.com/detail.asp?product_id=28850http://www.parallax.com/detail.asp?product_id=28850http://www.parallax.com/detail.asp?product_id=800-00030


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The port will be listed as "USB Serial Port (COMx)" as shown below (Note

that your COM port assignment may differ from the image below). Record

your COM port number for programs that require manual assignment.

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PDI Studio V 5

Pin Description

-

PIN Name Description1 SOUT Serial Out: Rx (DB9 pin 2/ DB25 pin3)2 SIN Serial In: Tx (DB9 pin 3/ DB25 pin2)3 ATN Attention: DTR (DB9 pin 4/ DB254 VSS System Ground5-20 PO-P15 General Purpose I/O21 VDD 5V DC22 RES Reset23 VSS System Ground (same as pin 4)24 VIN Unregulated Power In


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3. Installation and Test of Software

1. Get the Software

- If you have the CD : go Software BASIC Stamp Windows

- If you dont have the CD, go to http://www.parallax.com downloads

BASIC Stamp Software

2. Install and Run the program

3. Testyour PCs connection to the BASIC Stamp: Run Identify (from the menu

bar)

4. Setting the board type Enter $STAMP directive into the Editor Window by

clicking on the toolbar icon.

5. Setting the version or programming language Enter $PBASIC directive

into the Editor Window by clicking on the toolbar icon (It depends on what board

you have. See page 2 ofProgramming with the Basic Stamp Editor)

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http://www.parallax.com/http://www.parallax.com/


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6. Type the line DEBUG Hello World! below the compiler directive

7. Download this program into the BASIC Stamp. You may (1) select Run Run

from menu bar, (2) press Ctrl-R from the keyboard, or (3) click on the Run icon

on the toolbar.

- If the program typed correctly, a progress bar window should appear, then

Debug terminal window should appear and display Hello World!

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' Trig routines courtesy Tracy Allen, PhD. (www.emesystems.com)

Arccosine:

disp = disp */ 983 / 3 ' normalize input to 127

angle = 63 - (disp / 2) ' approximate angle

DO ' find angle

IF (COS angle


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#SELECT $STAMP

#CASE BS2, BS2E

Scale CON $200 ' 2.0 us per unit

#CASE BS2SX

Scale CON $0CC ' 0.8 us per unit

#CASE BS2P

Scale CON $0C0 ' 0.75 us per unit

#CASE BS2PEScale CON $1E1 ' 1.88 us per unit

#ENDSELECT

HiPulse CON 1 ' measure high-going pulse

LoPulse CON 0

DegSym CON 176 ' degrees symbol

' -----[ Variables ]-------------------------------------------------------

pulse VAR Word ' pulse input

xmG VAR Word ' g force (1000ths)

ymG VAR Word

brads VAR Word ' binary radians

degrees VAR Word

' -----[ Initialization ]--------------------------------------------------

Setup:

DEBUG "Memsic 2125 Rotation", CR,

"--------------------"

' -----[ Program Code ]----------------------------------------------------

Main:

DO

GOSUB Read_G_Force ' read X and Y

brads = (xmG / 8) ATN (ymG / 8) ' calculate angle

degrees = brads */ 360 ' convert to degrees

DEBUG CRSRXY, 0, 3

DEBUG "Axis A(g)", CR,

"X ", (xmG.BIT15 * 13 + " "),

DEC (ABS xmG / 1000), ".", DEC3 (ABS xmG), " g", CR,

"Y ", (ymG.BIT15 * 13 + " "),

DEC (ABS ymG / 1000), ".", DEC3 (ABS ymG), " g", CR, CR,

"Tilt = ", DEC3 brads, " Brads", CR,

" ", DEC3 degrees, " Degrees"

PAUSE 200 ' update about 5x/second

LOOP

END

' -----[ Subroutines ]-----------------------------------------------------

Read_G_Force:

PULSIN Xin, HiPulse, pulse ' read pulse outputpulse = pulse */ Scale ' convert to uSecs

xmG = ((pulse / 10) - 500) * 8 ' calc 1/1000 g

PULSIN Yin, HiPulse, pulse

pulse = pulse */ Scale

ymG = ((pulse / 10) - 500) * 8

RETURN

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3) Motion Detector

To adjust sensitivity, change the XLimit, theYLimit, and the Sample Delay

constants (should be 100ms or greater).

To determine how long motion/vibration is present before triggering the

alarm , to change the Alarm Level.

' =========================================================================

'

' File...... MEMSIC2125-Motion.BS2

' Purpose... Detects continuous motion for given period

' Author.... Parallax (based on code by A. Chaturvedi of Memsic)

' E-mail.... [email protected]

' Started...

' Updated... 15 JAN 2003

'

' {$STAMP BS2}

' {$PBASIC 2.5}

'

' =========================================================================

' -----[ Program Description ]---------------------------------------------

'

' Monitors X and Y inputs from Memsic 2125 and will trigger alarm if

' continuous motion is detected beyond the threshold period.

' -----[ I/O Definitions ]-------------------------------------------------

Xin PIN 8 ' X pulse input

Yin PIN 9 ' Y pulse input

ResetLED PIN 10 ' reset LED

AlarmLED PIN 11 ' alarm LED

' -----[ Constants ]-------------------------------------------------------

HiPulse CON 1 ' measure high-going pulseLoPulse CON 0

SampleDelay CON 500 ' 0.5 sec

AlarmLevel CON 5 ' 5 x SampleDelay

XLimit CON 5 ' x motion max

YLimit CON 5 ' y motion max

' -----[ Variables ]-------------------------------------------------------

xCal VAR Word ' x calibration value

yCal VAR Word ' y calibration value

xMove VAR Word ' x sample

yMove VAR Word ' y sample

xDiff VAR Word ' x axis difference

yDiff VAR Word ' y axis difference

moTimer VAR Word ' motion timer

' -----[ Initialization ]--------------------------------------------------

Initialize:

LOW AlarmLED ' alarm off

moTimer = 0 ' clear motion timer

Read_Cal_Values:

PULSIN Xin, HiPulse, xCal ' read calibration values

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PULSIN Yin, HiPulse, yCal

xCal = xCal / 10 ' filter for noise & temp

yCal = yCal / 10

HIGH ResetLED ' show reset complete

PAUSE 1000

LOW ResetLED

' -----[ Program Code ]----------------------------------------------------Main:

DO

GOSUB Get_Data ' read inputs

xDiff = ABS (xMove - xCal) ' check for motion

yDiff = ABS (yMove - yCal)

IF (xDiff > XLimit) OR (yDiff > YLimit) THEN

moTimer = moTimer + 1 ' update motion timer

IF (moTimer > AlarmLevel) THEN Alarm_On

ELSE

moTimer = 0 ' clear motion timer

ENDIF

LOOP

END

' -----[ Subroutines ]-----------------------------------------------------

' Sample and filter inputs

Get_Data:

PULSIN Xin, HiPulse, xMove ' take first reading

PULSIN Yin, HiPulse, yMove

xMove = xMove / 10 ' filter for noise & temp

yMove = yMove / 10

PAUSE SampleDelay

RETURN

' Blink Alarm LED

' -- will run until BASIC Stamp is reset

Alarm_On:

DO

TOGGLE AlarmLED ' blink alarm LED

PAUSE 250

LOOP ' loop until reset

TOut

Since the Memsic 2125 is a thermal device, the temperature is available from

the TOut pin and can be measured using an external analog to digital

converter Details

Output calibrated to 1.25V at 25.0C

Output change: 5 milivolts per degree C

PDI Studio V 14

bs accelerometer rev1

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