MicroPython Forum (Archive)

Posted: **Thu Mar 24, 2022 9:03 pm**

Hi !
I try to get working the accelerometer W61P with micropython.

The documentation of all the i2c adresses are described here : https://drive.google.com/file/d/1d0UI3R ... sp=sharing

My verry simple code is here :

Code: Select all

from machine import Pin, I2C
import utime 
# construct spi
bus=I2C(scl=machine.Pin('Y9'), sda=machine.Pin('Y10'),freq=400000)
# send 0x2000 to soft reset sensor and wait 3 sec
re = bytearray([0x1a,0x40,0x00])
bus.writeto(0x50,re)
re2 = bytearray([0x00,0,0x00])
#bus.writeto(0x50,re2)
utime.sleep(1)
#scan for the sensor address
print(bus.scan())

while True :
    #Initialize Sensor send 0x1000 to sensor to start continuous measurement
    buf_angle = bus.readfrom_mem(0x50,0x3d,6)

    X_Angle = ((buf_angle[1]<<8)|buf_angle[0])/32768*180
    Y_Angle = ((buf_angle[3]<<8)|buf_angle[2])/32768*180
    Z_Angle = ((buf_angle[5]<<8)|buf_angle[4])/32768*180
    print('X_Angle',X_Angle,'Y_Angle',Y_Angle,'Z_Angle',Z_Angle)

    buf_angular_velocity = bus.readfrom_mem(0x50,0x37,6)
    X_AngVelocity = ((buf_angular_velocity[1]<<8)|buf_angular_velocity[0])/32768*2000
    Y_AngVelocity = ((buf_angular_velocity[3]<<8)|buf_angular_velocity[2])/32768*2000
    Z_AngVelocity = ((buf_angular_velocity[5]<<8)|buf_angular_velocity[4])/32768*2000
    print('X_AngVelocity',X_AngVelocity,'Y_AngVelocity',Y_AngVelocity,'Z_AngVelocity',Z_AngVelocity)


    buf_acceleration = bus.readfrom_mem(0x50,0x34,8)
    print(buf_acceleration)
    X_Acc = ((buf_acceleration[1]<<8)|buf_acceleration[0])/32768*16
    Y_Acc = ((buf_acceleration[3]<<8)|buf_acceleration[2])/32768*16
    Z_Acc = ((buf_acceleration[5]<<8)|buf_acceleration[4])/32768*16
    Temp  = ((buf_acceleration[7]<<8)|buf_acceleration[6])/32768*16
    print('X_Acc',X_Acc,'Y_Acc',Y_Acc,'Z_Acc',Z_Acc)
    print('temp',Temp)
    
    break

I get some problems.
1) I can't manage to change the i2c adress of this chip.
I tried to do that according to the sec 5.2.28 of the documentation (link above)

Code: Select all

re = bytearray([0x1a,0x40,0x00])
bus.writeto(0x50,re)
re2 = bytearray([0x00,0,0x00])
bus.writeto(0x50,re2)
utime.sleep(1)

The first line is suppose to change the adress and the second one to save the new adress, but after restarting the chip, nothing change...

Second problem, I get some weird values for the acceleration :

Code: Select all

buf_angle = bus.readfrom_mem(0x50,0x3d,6)

    
    buf_acceleration = bus.readfrom_mem(0x50,0x34,8)
    print(buf_acceleration)
    X_Acc = ((buf_acceleration[1]<<8)|buf_acceleration[0])/32768*16
    Y_Acc = ((buf_acceleration[3]<<8)|buf_acceleration[2])/32768*16
    Z_Acc = ((buf_acceleration[5]<<8)|buf_acceleration[4])/32768*16
    Temp  = ((buf_acceleration[7]<<8)|buf_acceleration[6])/32768*16
    print('X_Acc',X_Acc,'Y_Acc',Y_Acc,'Z_Acc',Z_Acc)
    print('temp',Temp)

The temp is egal to zero, and the Y_Acc is 30 and constant, even if the sensor is stead on my table ...

I'am sure is just a little small things, but I did not find my way alone, so thanks by advance if you find something that could help !

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