I2C Bus Error
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Good evening,
I'm new in pycom programming. What I have to do is to acquire data from an IMU BNO055 with my WiPy 3.0.
Here you may find the library I'm using:#IMU LIBRARY #This is a library for the BNO055 orientation sensor import pycom import struct import time from machine import I2C #configure the I2C bus: use default PIN assignments (SDA = P09, SCL = P10) i2c = I2C(0) # configure the I2C bus i2c.init(I2C.MASTER, baudrate=15000) # init as a master baudrate = freq di lettura del dato # I2C addresses ADDRESS_B = 0x28 #This is the alternative I2C address; 0101000b DEFAULT_ADDRESS = 0x29 #This is the default I2C address of the BNO055 device; 0101001b BNO055_ID = 0xA0 #Page id register definition PAGE_ID_ADDR = 0x07 #Read: Number of currently selected page; Write: Change page, 0x00 or 0x01 #Registrer Descriprion """The entire communication with the device is performed by reading from and writing to register. Regoster have width of 8 bits. There are several registers which are either completely or partially marked as 'reserved'. It is recommended not to use register at all which are completely marked as 'reserved'. The register map is separated into two logical pages, Page 1 contains sensor specific configuration data and Page 0 contais all other cofiguration parameters and output data. """ #PAGE 0 REGISTER DEFINITION CHIP_ID_ADDR = 0X00 #BNO055 CHIP ID, chip identification chip, read only fixed value 0x0A ACC_ID_ADDR = 0X01 #ACC CHIP ID, chip identification accelerometer device, read only fixed value oxFB MAG_ID_ADDR = 0x02 #MAG CHiP ID, chip id of the magnetometer device, read only fixed value 0x32 GYR_ID_ADDR = 0x03 #GYRO CHiP ID, chip id of the gyroscope device, read only fixed value 0x0F SW_REV_LSB_ADDR = 0X04 #Lower byte of SW Revision ID, read only fixed value depending on SW revision programmed on microcontroller SW_REV_MSB_ADDR = 0X05 #Upper byte of SW Revision ID, read only fixed value depending on SW revision programmed on microcontroller BL_REV_ID_ADDR = 0x06 #Bootloader version, identifies the version of the bootloader in the microcontroller, read only #Acceleration Data Registers """In fusion mode the fusion algorithm outpt offset compensated acceleration data for each axis X/Y/Z, the output data can be read from the appropriate ACC_DATA_<axis>_LSB and ACC_DATA_<axis>_MSB register. """ ACC_DATA_X_LSB = 0X08 #Lower byte of X axis Acceleration data, read only ACC_DATA_X_MSB = 0X09 #Upper byte of X axis Acceleration data, read only ACC_DATA_y_LSB = 0X0A #Lower byte of Y axis Acceleration data, read only ACC_DATA_Y_MSB = 0X0B #Upper byte of Y axis Acceleration data, read only ACC_DATA_Z_LSB = 0X0C #Lower byte of Z axis Acceleration data, read only ACC_DATA_Z_MSB = 0X0D #Upper byte of Z axis Acceleration data, read only #Magnetometer Data Registers """In fusion mode the fusion algorithm output offset compensated magnetic field streght data for each axis X/Y/Z, the output data can be read from the appropriate MAG_DATA_<axis>_LSB and MAG_DATA_<axis>_MSB register. """ MAG_DATA_X_LSB = 0X0E #Lower byte of X axis Magnetometer data, read only MAG_DATA_X_MSB = 0X0F #Upper byte of X axis Magnetometer data, read only MAG_DATA_Y_LSB = 0X10 #Lower byte of Y axis Magnetometer data, read only MAG_DATA_Y_MSB = 0X11 #Upper byte of Y axis Magnetometer data, read only MAG_DATA_Z_LSB = 0X12 #Lower byte of Z axis Magnetometer data, read only MAG_DATA_Z_MSB = 0X13 #Upper byte of Z axis Magnetometer data, read only #Gyro Data Registers """In fusion mode the fusion algorithm output offset compensated angular velocity data for each axis X/Y/Z, the output data can be read from the appropriate GYR_DATA_<axis>_LSB and GYR_DATA_<axis>_MSB register. """ GYR_DATA_X_LSB = 0X14 #Lower byte of X axis Gyroscope data, read only GYR_DATA_X_MSB = 0X15 #Upper byte of X axis Gyroscope data, read only GYR_DATA_Y_LSB = 0X16 #Lower byte of Y axis Gyroscope data, read only GYR_DATA_Y_MSB = 0X17 #Upper byte of Y axis Gyroscope data, read only GYR_DATA_Z_LSB = 0X18 #Lower byte of Z axis Gyroscope data, read only GYR_DATA_Z_MSB = 0X19 #Upper byte of Z axis Gyroscope data, read only #Orientation: orientation output only available in fusion operation modes. #Euler Angles Data Registers """The fusion algorithm output offset and tilt compensated orientation data in Euler angles format for each DOF Heading/Roll/Pitch, the output data can be read from the appropriate EUL<dof>_LSB and EUL_<dof>_MSB registers. """ EUL_DATA_X_LSB = 0X1A #Lower byte of heading data, read only EUL_DATA_X_MSB = 0X1B #Upper byte of heading data, read only EUL_DATA_Y_LSB = 0X1C #Lower byte of roll data, read only EUL_DATA_Y_MSB = 0X1D #Upper byte of roll data, read only EUL_DATA_Z_LSB = 0X1E #Lower byte of pitch data, read only EUL_DATA_Z_MSB = 0X1F #Upper byte of pitch data, read only #Quaternion Data Registers """The fusion algorithm output offset and tilt compensated orientation data in Euler angles format for each DOF Heading/Roll/Pitch, the output data can be read from the appropriate EUL<dof>_LSB and EUL_<dof>_MSB registers. """ QUA_DATA_W_LSB = 0X20 #Lower byte of w axis quaternion data, read only QUA_DATA_W_MSB = 0X21 #Upper byte of w axis quaternion data, read only QUA_DATA_X_LSB = 0X22 #Lower byte of X axis quaternion data, read only QUA_DATA_X_MSB = 0X23 #Upper byte of X axis quaternion data, read only QUA_DATA_Y_LSB = 0X24 #Lower byte of Y axis quaternion data, read only QUA_DATA_Y_MSB = 0X25 #Upper byte of Y axis quaternion data, read only QUA_DATA_Z_LSB = 0X26 #Lower byte of Z axis quaternion data, read only QUA_DATA_Z_MSB = 0X27 #Upper byte of Z axis quaternion data, read only #Linear Acceleration Data Registers """Linear acceleration output only available in fusion operating modes. The fusion algorithm output linear acceleration data for each axis x/y/z, the output data can be read from the appropriate LIA_DATA_<axis>_LSB and LIA_DATA_<axis>_MSB registers. """ LIA_DATA_X_LSB = 0X28 #Lower byte of X axis Linear Acceleration data, read only LIA_DATA_X_MSB = 0X29 #Upper byte of X axis Linear Acceleration data, read only LIA_DATA_Y_LSB = 0X2A #Lower byte of Y axis Linear Acceleration data, read only LIA_DATA_Y_MSB = 0X2B #Upper byte of Y axis Linear Acceleration data, read only LIA_DATA_Z_LSB = 0X2C #Lower byte of Z axis Linear Acceleration data, read only LIA_DATA_Z_MSB = 0X2D #Upper byte of Z axis Linear Acceleration data, read only #Gravity Vector Data Registers """Gravity Vector output only available in fusion operating modes. The fusion algorithm output gravity vector data for each axis x/y/z, the output data can be read from the appropriate GRV_DATA_<axis>_LSB and GRV_DATA_<axis>_MSB registers. """ GRV_DATA_X_LSB = 0X2E #Lower byte of X axis gravity vector data, read only GRV_DATA_X_MSB = 0X2F #Upper byte of X axis gravity vector data, read only GRV_DATA_Y_LSB = 0X30 #Lower byte of Y axis gravity vector data, read only GRV_DATA_Y_MSB = 0X31 #Upper byte of Y axis gravity vector data, read only GRV_DATA_Z_LSB = 0X32 #Lower byte of Z axis gravity vector data, read only GRV_DATA_Z_MSB = 0X33 #Upper byte of Z axis gravity vector data, read only #Temperature Data Register TEMP = 0x34 #Read only, data output source can be selectednby updating the TEMP_SOURCE register TEMP_SOURCE = 0X40 #The temperature source can be selected by writing to this register. TEMP_SOURCE_ACC = 0x00 #xxxxxx00b, the source is the accelerometer TEMP_SOURCE_GYR = 0x01 #xxxxxx01b, the source is the gyroscope #Status Registers CALIB_STAT = 0X35 #The register can be read to see the calibration status of the gyro, the acc and the magn SELFTEST_RESULT = 0X36 INTR_STAT = 0X37 SYS_CLK_STAT = 0X38 SYS_STAT = 0X39 SYS_ERR = 0X3A #Unit selection Register UNIT = 0x3B """"The measurement units for the various data outputs can be configured by writing to the UNIT_SEL register -bit 0 select acceleration units, xxxxxxx0b m/s^2, xxxxxxx1b mg -bit 1 select angular rate units, xxxxxx0xb Dps, xxxxxx1xb RPS -bit 2 select euler units, xxxxx0xxb Degrees, xxxxx1xxb Radians -bit 3 reserved -bit 4 select temperature units, xxx0xxxxb Celsius, xxx1xxxx Fhahrenheit -bit 5-6 reserved -bit 7 select orentation mode. The data output format can be selectedby writing to the UNIT_SEL register, this allows user to switch between the orentation definition described by Windows and Android operating system. """ #Mode Registers OPR_MODE = 0x3D #Register to configure the operation mode. Bits <7:4> reserved PWR_MODE = 0x3E #Register to configure the power modes. Bits <7:2> reserved SYS_TRIGGER = 0x3F #Axis Remap Registers """The axis of the device can be re-configured to the new reference axis. -Bit <7:3> are reserved. -Bit <2> remapped X axis sign. -Bit <1> remapped Y axis sign. -Bit <0> remapped Z axis sign. Value 0 = positive, value 1 = negative. """ AXIS_MAP_CONFIG = 0x41 #bit<7:6> are reserved, 00b X-Axis bit<0:1>, 01b Y-Axis bit<2:3>, 10b Z-Axis bit<4:5>. AXIS_MAP_SIGN = 0x42 #Remapped axis signed. #Axis Remap Values AXIS_DEFAULT = 0x24 #The default value is: Xaxis = X, Y axis =m Y, Z axis = Z; xx100100b REMAP_X = 0x00 REMAP_Y = 0x01 REMAP_Z = 0x02 REMAP_POSITIVE = 0x00 REMAP_NEGATIVE = 0x01 #Accelerometer Offset registers """There are 6 bytes required to configre the accelerometer offset. Configuration will take place only when the user writes the last byte. """ ACCEL_OFFSET_X_LSB = 0X55 ACCEL_OFFSET_X_MSB = 0X56 ACCEL_OFFSET_Y_LSB = 0X57 ACCEL_OFFSET_Y_MSB = 0X58 ACCEL_OFFSET_Z_LSB = 0X59 ACCEL_OFFSET_Z_MSB = 0X5A # Magnetometer Offset registers """There are 6 bytes required to configre the magnetometer offset. Configuration will take place only when the user writes the last byte. """ MAG_OFFSET_X_LSB = 0X5B MAG_OFFSET_X_MSB = 0X5C MAG_OFFSET_Y_LSB = 0X5D MAG_OFFSET_Y_MSB = 0X5E MAG_OFFSET_Z_LSB = 0X5F MAG_OFFSET_Z_MSB = 0X60 # Gyroscope Offset registers """There are 6 bytes required to configre the gyroscope offset. Configuration will take place only when the user writes the last byte. """ GYRO_OFFSET_X_LSB = 0X61 GYRO_OFFSET_X_MSB = 0X62 GYRO_OFFSET_Y_LSB = 0X63 GYRO_OFFSET_Y_MSB = 0X64 GYRO_OFFSET_Z_LSB = 0X65 GYRO_OFFSET_Z_MSB = 0X66 # Radius registers """ The radius of accelerometer, magnetometer and gyroscope can be configured in the following registers. There are 4 bytes (2 bytes for each accelerometer and magnetometer) to configure the radius. Configuration will take place only when user writes to the last byte. """ ACCEL_RADIUS_LSB = 0X67 ACCEL_RADIUS_MSB = 0X68 MAG_RADIUS_LSB = 0X69 MAG_RADIUS_MSB = 0X6A #Operation Mode #The default operation mode after power-on (or RESET) is CONFIGMODE, this mode is used to configure BNO. #CONFFIGMODE is the only mode in which all the writable register map entries can be changed. #The operating mode can be selected by writing to the OPR_MODE register. CONFIGMODE = 0X00 ACCONLY = 0X01 #Non-Fusion Mode MAGONLY = 0X02 #Non-Fusion Mode GYRONLY = 0X03 #Non-Fusion Mode ACCMAG = 0X04 #Non-Fusion Mode ACCGYRO = 0X05 #Non-Fusion Mode MAGGYRO = 0X06 #Non-Fusion Mode AMG = 0X07 #Non-Fusion Mode IMUPLUS = 0X08 #Fusion Mode COMPASS = 0X09 #Fusion Mode M4G = 0X0A #Fusion Mode NDOF_FMC_OFF = 0X0B #Fusion Mode NDOF = 0x0C #Operation mode that use accel, gyro and mag. Reg Value xxxx1100b. There are some different types. #Power Modes #The power mode can be selected by writing to the PWR_MODE register. #As default at start-up the BNO055 will run in Normal mode. #If no activity is detected for a configurable duration (5 seconds), the BNO055 enters the low power mode. #In normal mode all sensors required fot the selected operating mode are always switched ON. NormalMode = 0x00 #It is the default mode. Reg Value xxxxxx00b LowPowerMode = 0x01 #In this mode only accelerometer is active. Reg Value xxxxxx01b SuspendMode = 0x02 #THe system is paused and all the sensor and the microcontroller are put into sleep mode. #PAGE 1 REGISTER DEFINITION #Sensor configuration ACC_CONFIG = 0x08 #The accelerometer configuration can be changed by writing to the ACC_CONFIG register MAG_CONFIG = 0x09 #The magnetometer configuration can be changed by writing to the MAG_CONFIG register #The gyroscope configuration can be changed by writing to the GYR_CONFIG register GYR_CONFIG_0 = 0x0A #Bit <5:3> GYR-Bandwidth, bit <2:0> GYR-Range GYR_CONFIG_1 = 0x0B #Bit <2:0> GYR-power-mode #VALUES ACC_DATA = ACC_DATA_X_LSB MAG_DATA = MAG_DATA_X_LSB GYR_DATA = GYR_DATA_X_LSB EUL_DATA = EUL_DATA_X_LSB LIA_DATA = LIA_DATA_X_LSB GRV_DATA = GRV_DATA_X_LSB QUA_DATA = QUA_DATA_W_LSB #Operation Modes _modes = { "acc" : ACCONLY, "magn": MAGONLY, "gyro": GYRONLY, "accmag": ACCMAG, "accgyro": ACCGYRO, "maggyro": MAGGYRO, "amg": AMG, "imu": IMUPLUS, "comp": COMPASS, "m4g": M4G, "ndof_off": NDOF_FMC_OFF, "ndof": NDOF } #Power Modes _power ={ "normal" : NormalMode, "low" : LowPowerMode, "suspend" : SuspendMode } def set_configmode(): #make sure we are on page 0 i2c.writeto_mem(DEFAULT_ADDRESS, PAGE_ID_ADDR, 0) #Enter config mode i2c.writeto_mem(DEFAULT_ADDRESS, OPR_MODE, CONFIGMODE) time.sleep(0.03) #Delay for 30 milliseconds #Enter operation mode with ' ' def set_mode(mode): if mode not in _modes: raise ValueError set_configmode() time.sleep(0.03) #Delay for 30 milliseconds i2c.writeto_mem(DEFAULT_ADDRESS, OPR_MODE, _modes[mode]) time.sleep(0.02) #Delay for 20 milliseconds #configure different power mode def set_power(power): if power not in _power: raise ValueError i2c.writeto_mem(DEFAULT_ADDRESS, OPR_MODE, CONFIGMODE) time.sleep(0.03) #Delay for 30 milliseconds i2c.writeto_mem(DEFAULT_ADDRESS, PWR_MODE, _power[power]) #configure default units def set_units(): i2c.writeto_mem(DEFAULT_ADDRESS, UNIT, 0) def set_acc(): i2c.writeto_mem(DEFAULT_ADDRESS, PAGE_ID_ADDR, 0x01) i2c.writeto_mem(DEFAULT_ADDRESS, OPR_MODE, ACC_CONFIG) time.sleep(0.03) i2c.writeto_mem(DEFAULT_ADDRESS, ACCEL_OFFSET_X_LSB, 0x00) #Read Vector def read_vector(address, count=3): # Read count number of 16-bit signed values starting from the provided # address. Returns a tuple of the values that were read. data = i2c.readfrom_mem(DEFAULT_ADDRESS, address, count*2) result = [0]*count for i in range(count): result[i] = ((data[i*2+1] << 8) | data[i*2]) & 0xFFFF if result[i] > 32767: result[i] -=65536 return result def read_vector_int(adress, count=3): data = i2c.readfrom_mem(DEFAULT_ADDRESS, address, count*2) # result = [0]*count # for i in range(count): # result[i] = ((data[i*2+1] << 8) | data[i*2]) & 0xFFFF return data def get_calibration(): """Return the sensor's calibration data and return it as an array of 22 bytes. Can be saved and then reloaded with the set_calibration function to quickly calibrate from a previously calculated set of calibration data. """ # Switch to configuration mode set_configmode() # Read the 22 bytes of calibration data and convert it to a list (from # a bytearray) so it's more easily serialized should the caller want to # store it. cal_data = list(i2c.readfrom_mem(DEFAULT_ADDRESS, ACCEL_OFFSET_X_LSB, 22)) # Go back to normal operation mode. set_mode('ndof') # CAMBIARE MODALITà return cal_data def set_calibration(data): """Set the sensor's calibration data using a list of 22 bytes that represent the sensor offsets and calibration data. This data should be a value that was previously retrieved with get_calibration (and then perhaps persisted to disk or other location until needed again). """ # Check that 22 bytes were passed in with calibration data. if data is None or len(data) != 22: raise ValueError('Expected a list of 22 bytes for calibration data.') # Switch to configuration mode, as mentioned in section 3.10.4 of datasheet. set_configmode() # Set the 22 bytes of calibration data. i2c.writeto_mem(DEFAULT_ADDRESS, ACCEL_OFFSET_X_LSB, data) # Go back to normal operation mode. set_mode('ndof') #Read accelerometer def get_accelerometer(): #Return the current accelerometer reading as a tuple of X, Y, Z values in maters/second^2 #print("funzione get accelerometer") x, y, z = read_vector(ACC_DATA) return (x/100.0, y/100.0,z/100.0) #Read magnetometer def get_magnetometer(): #Return the current magnetometer reading as a tuple of X, Y, Z values in micro-Tesla x, y, z = read_vector(MAG_DATA) return (x/16.0, y/16.0, z/16.0) #Read gyroscope def get_gyroscope(): #Return the current gyroscope (angular velocity) reading as a tuple of X, Y, Z values in degrees per second print("funzione get gyroscope") x, y, z = read_vector(GYR_DATA) return (x/900.0, y/900.0, z/900.0) #Read euler def get_euler(): #Return the current absolute orientation as a tuple of heading, roll, and pitch euler angles in degrees #print("funzione get euler") heading, roll, pitch = read_vector(EUL_DATA) return (heading/16.0, roll/16.0, pitch/16.0) def get_euler_int(): data = i2c.readfrom_mem(DEFAULT_ADDRESS, EUL_DATA, 3*2) return data #Read linear acceleration def get_linear_acceleration(): #Return the current linear acceleration (acceleration from movement, not from gravity) #reading as a tuple of X, Y, Z values in meters/second^2 print("funzione get linear acceleration") x, y, z = read_vector(LIA_DATA) return (x/100.0, y/100.0, z/100.0) #Read gravity def get_gravity(): #Return the current gravity acceleration reading as a tuple of X, Y, Z values in meters/second^2 print("funzione get gravity") x, y, z = read_vector(GRV_DATA) return (x/100.0, y/100.0, z/100.0) #Read quaternion def get_quaternion(): #Return the current orientation as a tuple of X, Y, Z, W quaternion values print("funzione get quaternion") w, x, y, z = read_vector(QUA_DATA, 4) # Scale values scale = (1.0 / (1<<14)) return (x*scale, y*scale, z*scale, w*scale) #Read temperature def get_temperature(): #Retrieves the current temperature in Celtius. print("funzione get temperature") temp = i2c.readfrom_mem(DEFAULT_ADDRESS, TEMP, 1)[0] if temp > 127: return temp - 256 else: return tempAnd here you may find the code I'm running:
import machine import pycom from machine import Timer from machine import idle import time #import lib_imu import lib_imu2 from machine import I2C from math import sqrt from machine import PWM from machine import SD import gc import os #sd = SD() # os.chdir('/sd') from machine import idle # # add the other imports here that you need # # acquire values. The paramters of the constructor are: # class Acquire: def __init__(self, filename_imu1, period=0.02, runtime=60): self.fileIMU1 = open(filename_imu1, "w") self.temp = Timer.Chrono() self.busy = True self.runtime = runtime self.temp.start() self.alarm = Timer.Alarm(self.sample_and_write, period, periodic=True) # and add all other init tasks you need def stop(self): self.alarm.cancel() self.fileIMU1.close() def sample_and_write(self, alarm): passed = self.temp.read() # check, if done, if the time for sampling is expired, then stop if passed >= self.runtime: self.stop() self.busy = False print('end') else: # get data and write #acc = lib_imu.get_accelerometer() #eul = lib_imu.get_euler() #acc2 = lib_imu2.get_accelerometer() eul2 = lib_imu2.get_euler() self.fileIMU1.write(repr(passed) + repr(eul2) + "\n") # Esercizi Romberg Imu 1- 0x29 - l5 - accelerometro # and what else you have to do. # now here the skeleton main_ # #sd = SD() # os.chdir('/sd') # set up the hardware # Scala Berg: imu L5 - lib_imu - acc # lib_imu.set_acc() # time.sleep(0.01) # lib_imu.set_configmode() # time.sleep(0.01) # lib_imu.set_units() # time.sleep(0.01) # lib_imu.set_mode('ndof') # time.sleep(0.01) # scala Romberg time.sleep(1) lib_imu2.set_acc() time.sleep(0.01) lib_imu2.set_configmode() time.sleep(0.01) lib_imu2.set_units() time.sleep(0.01) lib_imu2.set_mode('ndof') time.sleep(0.01) print('start') acquire = Acquire('eulonly.txt', 0.015, 30) # dati_Tandem.txt 30 s # dati_LegUp.txt 10 s # # now get the data, until it's done # while acquire.busy: idle() # # whatever you have to do for cleanup, do it here #The error I'm obtaining is the following one:
♦Traceback (most recent call last): File "<stdin>", line 76, in <module> File "lib_imu2.py", line 303, in set_acc OSError: I2C bus errorThe IMU I'm using has a pullup resistor. Can someone help me?
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@robert-hh I'm sorry for the delayed response. The error was due to the fact I was using a 3.0 WiPy version, by changing it to the previous (2.0) it works!!
Thank you for the support!
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@Guendalina-Neuro As @livius said, it's usually a connection problem:
so:
- wires: GND -> GND, Vcc->3V3, SDA -> P9, SCL to P10.
- Pull-Up: Check that the BN055 board has pull-up resistors.
- I2C Address. The default of the lib is 0x29 or 41 decimal. But it may be different.
You can check that by connecting the BNO055 and run:
from machine import I2C i2c=I2C(0) i2c.scan()That should return a list with the detected I2C devices on the bus. The numbers are decimal, so you might see 41 or 40. If you get an empty list, then there is a communication problem. Then start over checking the wiring.
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@livius yes, they are connected correctly. Do you have other suggestions?
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did you connected i2c to SDA = P09, SCL = P10?
PS. i really hate library written in this way ;-)
It should be class with methods and propertie, and i2c should be as parameter, only when ommited it should use defaults...
