3-Axis Accelerometer (LIS302DL)

[Gusse]

Hi Rodik,

What is your planned application in car?

If you are planning to monitor movements (i.e alarm use), then placing is not a problem. You can reset acceleration/tilt values for interrupt at any angle.
If you are keen to know real acceleration values in all axis, then IC need to be at level, X&Y=0, Z=90. Bit more demanding, but ... Constant tilting will give static values.

Values need to be read from IC via I2C, so if constant reading is needed then you have to do reading loop for that purpose. Data can be put to serial port as well as to LCD, so that is no problem. You have to adjust output part of the code.

BR,
-Gusse-

[rodrik]

Hi Gusse,

Thank you very much for your reply.
I am sorry for delay. We moved to new house, I got internet just few days ago. I need to detect lifting big garbadge container. I can put the IC verticaly in manner that Z can detect forward movement X lift up detection. Y its useless. The G values not important jus detect lift up and if moves forward (towing) and stop. I can read the values via serial (SEROUT) pin.
As I understand , I have configure a value if its exeedes , INT lines falls to "0" logic. I look at ZIP file as I see the "Power_3D VAR PortD.5 'Power_3D" its must be connected to LIS302DL's VCC. What about pin#1 ? (VDD_IO)
Thanks again
Have a great weekend

Haim

[Gusse]

Hi Haim,

It is OK to put IC vertically and reset acceration/tilt values (HP_FILTER_RESET (23h)).
You have to configure certain parameters if you want to use interrupt. Here are couple of examples from working piece of codes:

Code to init accelerometer:

Accelerometer_Init:

    'Axes
    I2CAddress_3D = $20     'CTRL_REG1
    TEMP = %01000111        'DR=0, PD=1, FS=0, STP=00, Zen=1, Yen=1, Xen=1 (X,Y,Z enable, Output 100Hz)
    gosub I2C_Write_3D      
    '---------------------
    
    'Filters
    I2CAddress_3D = $21     'CTRL_REG2
    TEMP = %00000111        'SIM = 0, BOOT = 0, --,  FDS = 0, HP FF_WU2 = 0, HP FF_WU1 = 1, HP coeff2 = 1, HP coeff1 = 1 (HP 0.25Hz for FF_WU1)
    gosub I2C_Write_3D
    
    '---------------------
    
    'Interrupts
    I2CAddress_3D = $22     'CTRL_REG3
    TEMP = %00000001        'IHL = 0, PP_OD = 0, I2CFG2-0 = 000, I1CFG2-0 = 001 (FF_WU 1 = INT1)
    gosub I2C_Write_3D
    
    '---------------------
    
    'Sensitivity
    I2CAddress_3D = $32     'FF_WU_THS_1
    TEMP = $02              'DCRM = 0, THS6 = 0, THS5 = 0, THS4 = 0, THS3 = 0, THS2 = 0, THS1 = 1, THS0 = 0 (~36mg wake-up threshold, ~18mg step)
    gosub I2C_Write_3D      
    
    '---------------------
    
    'Duration
    I2CAddress_3D = $33     'FF_DURATION_1
    TEMP = $0D              'D7 = 0, D6 = 0, D5 = 0, D4 = 0, D3 = 1, D2 = 1, D1 = 0, D0 = 1 (130ms, 0 - 2.55s, 10ms step)
    gosub I2C_Write_3D      '0Ah = 100ms, 0Fh = 150ms, 14h = 200ms, 28h = 400ms, 32h = 500ms,
    
    '---------------------
    
    'Wake-Up Thresholds
    I2CAddress_3D = $30     'FF_WU_GFG_1
    TEMP = %01101010        'AOI = 0, LIR = 1, ZHIE = 1, ZLIE = 0, YHIE = 1, YLIE = 0, XHIE = 1, XLIE = 0 (wake-up above thresholde on x,y,z)
    gosub I2C_Write_3D
    
    '---------------------

Code how to deal when INT will occur:

Accelerometer:
    IF Int1_3D = 1 THEN         ' Int1_3D is IO pin for Interrup coming from 3D sensor
        gosub Accelerometer_Clear
        Accel_Alarm = 1         ' This is indecator that something must be done in main program        
    endif
    return

Accelerometer_Clear:            ' If sensor has moved during event hadling, then interrupt must be cleared once before new sequence
    I2CAddress_3D = $31         ' Clear interrupt request
    gosub I2C_Read_3D
    I2CAddress_3D = $23         ' Reset acceration/tilt value after interrupt 
    gosub I2C_Read_3D
    Return

Vdd_IO = Vdd = 5V. Even spec says 3.6V, I have used 5V already several years for same parts. Same voltage is used also for I2C pull-ups & CS (pins 1, 3, 6, 7).

[rodrik]

Thank you very much , I will try and let you know the results. If you need assistance for GSM and GPS, I am very very experienced
thanks again
haim