Hello,
I am reading acceleration data from a MPU9250 and I have the problem, that when I move the sensor, my y-value always stays constant (x-value and z-value change correctly).
Does someone know what the problem could be?
Gravity should stay the same, so perhaps you have mislabeled the y and the z.
Paul
The problem is most like in the code that you forgot to post. Please follow the instructions here: How to get the best out of this forum
Thank you for your reply! I am quite sure that the z-value is correct, because it is -1.
I forgot to mention that I have tried connecting to a raspberry with following python script:
lib:
import smbus,time
def MPU6050_start():
# alter sample rate (stability)
samp_rate_div = 0 # sample rate = 8 kHz/(1+samp_rate_div)
bus.write_byte_data(MPU6050_ADDR, SMPLRT_DIV, samp_rate_div)
time.sleep(0.1)
# reset all sensors
bus.write_byte_data(MPU6050_ADDR,PWR_MGMT_1,0x00)
time.sleep(0.1)
# power management and crystal settings
bus.write_byte_data(MPU6050_ADDR, PWR_MGMT_1, 0x01)
time.sleep(0.1)
#Write to Configuration register
bus.write_byte_data(MPU6050_ADDR, CONFIG, 0)
time.sleep(0.1)
#Write to Gyro configuration register
gyro_config_sel = [0b00000,0b010000,0b10000,0b11000] # byte registers
gyro_config_vals = [250.0,500.0,1000.0,2000.0] # degrees/sec
gyro_indx = 0
bus.write_byte_data(MPU6050_ADDR, GYRO_CONFIG, int(gyro_config_sel[gyro_indx]))
time.sleep(0.1)
#Write to Accel configuration register
accel_config_sel = [0b00000,0b01000,0b10000,0b11000] # byte registers
accel_config_vals = [2.0,4.0,8.0,16.0] # g (g = 9.81 m/s^2)
accel_indx = 0
bus.write_byte_data(MPU6050_ADDR, ACCEL_CONFIG, int(accel_config_sel[accel_indx]))
time.sleep(0.1)
# interrupt register (related to overflow of data [FIFO])
bus.write_byte_data(MPU6050_ADDR, INT_ENABLE, 1)
time.sleep(0.1)
return gyro_config_vals[gyro_indx],accel_config_vals[accel_indx]
def read_raw_bits(register):
# read accel and gyro values
high = bus.read_byte_data(MPU6050_ADDR, register)
low = bus.read_byte_data(MPU6050_ADDR, register+1)
# combine higha and low for unsigned bit value
value = ((high << 8) | low)
# convert to +- value
if(value > 32768):
value -= 65536
return value
def mpu6050_conv():
# raw acceleration bits
acc_x = read_raw_bits(ACCEL_XOUT_H)
acc_y = read_raw_bits(ACCEL_YOUT_H)
acc_z = read_raw_bits(ACCEL_ZOUT_H)
# raw temp bits
## t_val = read_raw_bits(TEMP_OUT_H) # uncomment to read temp
# raw gyroscope bits
gyro_x = read_raw_bits(GYRO_XOUT_H)
gyro_y = read_raw_bits(GYRO_YOUT_H)
gyro_z = read_raw_bits(GYRO_ZOUT_H)
#convert to acceleration in g and gyro dps
a_x = (acc_x/(2.0**15.0))*accel_sens
a_y = (acc_y/(2.0**15.0))*accel_sens
a_z = (acc_z/(2.0**15.0))*accel_sens
w_x = (gyro_x/(2.0**15.0))*gyro_sens
w_y = (gyro_y/(2.0**15.0))*gyro_sens
w_z = (gyro_z/(2.0**15.0))*gyro_sens
## temp = ((t_val)/333.87)+21.0 # uncomment and add below in return
return a_x,a_y,a_z,w_x,w_y,w_z
def AK8963_start():
bus.write_byte_data(AK8963_ADDR,AK8963_CNTL,0x00)
time.sleep(0.1)
AK8963_bit_res = 0b0001 # 0b0001 = 16-bit
AK8963_samp_rate = 0b0110 # 0b0010 = 8 Hz, 0b0110 = 100 Hz
AK8963_mode = (AK8963_bit_res <<4)+AK8963_samp_rate # bit conversion
bus.write_byte_data(AK8963_ADDR,AK8963_CNTL,AK8963_mode)
time.sleep(0.1)
def AK8963_reader(register):
# read magnetometer values
low = bus.read_byte_data(AK8963_ADDR, register-1)
high = bus.read_byte_data(AK8963_ADDR, register)
# combine higha and low for unsigned bit value
value = ((high << 8) | low)
# convert to +- value
if(value > 32768):
value -= 65536
return value
def AK8963_conv():
# raw magnetometer bits
loop_count = 0
while 1:
mag_x = AK8963_reader(HXH)
mag_y = AK8963_reader(HYH)
mag_z = AK8963_reader(HZH)
# the next line is needed for AK8963
if bin(bus.read_byte_data(AK8963_ADDR,AK8963_ST2))=='0b10000':
break
loop_count+=1
#convert to acceleration in g and gyro dps
m_x = (mag_x/(2.0**15.0))*mag_sens
m_y = (mag_y/(2.0**15.0))*mag_sens
m_z = (mag_z/(2.0**15.0))*mag_sens
return m_x,m_y,m_z
# MPU6050 Registers
MPU6050_ADDR = 0x68
PWR_MGMT_1 = 0x6B
SMPLRT_DIV = 0x19
CONFIG = 0x1A
GYRO_CONFIG = 0x1B
ACCEL_CONFIG = 0x1C
INT_ENABLE = 0x38
ACCEL_XOUT_H = 0x3B
ACCEL_YOUT_H = 0x3D
ACCEL_ZOUT_H = 0x3F
TEMP_OUT_H = 0x41
GYRO_XOUT_H = 0x43
GYRO_YOUT_H = 0x45
GYRO_ZOUT_H = 0x47
# start I2C driver
bus = smbus.SMBus(1) # start comm with i2c bus
gyro_sens,accel_sens = MPU6050_start() # instantiate gyro/accel
code:
from mpu9250_i2c import *
time.sleep(1) # delay necessary to allow mpu9250 to settle
print('recording data')
while 1:
try:
ax,ay,az,wx,wy,wz = mpu6050_conv() # read and convert mpu6050 data
except:
continue
print('{}'.format('-'*30))
print('accel [g]: x = {0:2.2f}, y = {1:2.2f}, z {2:2.2f}= '.format(ax,ay,az))
print('gyro [dps]: x = {0:2.2f}, y = {1:2.2f}, z = {2:2.2f}'.format(wx,wy,wz))
print('{}'.format('-'*30))
time.sleep(1)
This is the Arduino forum. Consider posting on the Raspberry Pi forum.
@charnky, your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advise on) your project 
See About the Installation & Troubleshooting category.
==
So you tried on a Raspberry Pi; did that give the correct results? Where is the Arduino code?
Hello, yes I have received correct data on the raspberry and I don't have any Arduino code, because my sensor is on an Arduino board but I can directly connect it with a raspberry
for example, when I don't move the sensor I get following data:
x = 0.03g y = 2g z = -0,91
when I move it, I get:
x = 1,23g y = 2g z = 2.3
so my problem is, that the y-value doesn't change when I move the sensor
Please explain with a wiring diagram; all connections including power and USB. A reasonably sized (300kB or so) photo of a hand-drawn one is fine.
Which Arduino board?
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