In the blog Rotationssensor MPU-6050 mit WebGL am Raspberry Pi visualisieren
Der Raspberry Pi ist zu vielem in der Lage, so können einfach Rotations- und Beschleunigugnswerte mittels eines Sensors, wie dem MPU-6050, ausgelesen werden. Das Ergebnis sind jedoch einfache Zahlen, worunter man sich im Normalfall nicht all zu viel vorstellen wird. Jedoch ist es sehr einfach diese Zahlen zu visualisieren. Dies geht in modernen Browsern ganz einfach mittels WebGL, womit man 2D und 3D Objekte im Browser rendern kann.
Setting up a VNC connection from phone to the raspi follow the instructions given at
https://magpi.raspberrypi.org/articles/vnc-raspberry-pi
Setting up the raspi as a wireless access point so that you can use VNC on a camping ground follow instructions given at https://www.raspberrypi.org/documentation/configuration/wireless/access-point.md This documentation assumes that we are using the standard 192.168.x.x IP addresses for our wireless network, so we will assign the server the IP address 192.168.4.1.
Note: Change default in sudo nano /etc/hostapd/hostapd.conf to something meaningful to you
ssid=NameOfNetwork # change this
hw_mode=g
channel=7
wmm_enabled=0
macaddr_acl=0
auth_algs=1
ignore_broadcast_ssid=0
wpa=2
wpa_passphrase=AardvarkBadgerHedgehog # change this
Follow instructions at MPU6050 (Accelerometer+Gyroscope) Interfacing with Raspberry Pi https://www.electronicwings.com/raspberry-pi/mpu6050-accelerometergyroscope-interfacing-with-raspberry-pi
from MPU6050_9Axis_MotionApps41.h
```uint8_t MPU6050::dmpGetYawPitchRoll(float data, Quaternion *q, VectorFloat *gravity) { // yaw: (about Z axis) data[0] = atan2(2q -> xq -> y - 2q -> wq -> z, 2q -> wq -> w + 2q -> xq -> x - 1); // pitch: (nose up/down, about Y axis) data[1] = atan(gravity -> x / sqrt(gravity -> ygravity -> y + gravity -> zgravity -> z)); // roll: (tilt left/right, about X axis) data[2] = atan(gravity -> y / sqrt(gravity -> xgravity -> x + gravity -> z*gravity -> z)); return 0;
The following output
Gyroscope ——– gyroscope_xout: -260 scaled: -2 gyroscope_yout: -154 scaled: -2 gyroscope_zout: 78 scaled: 0
acceleration_xout: -1048 scaled: -0.06396484375 acceleration_yout: -676 scaled: -0.041259765625 acceleration_zout: 16644 scaled: 1.01586914062 X Rotation: -2.32121150537 Y Rotation: 3.59994842011
is created by
[Measuring Rotation and acceleration with the Raspberry Pi](http://www.raspberrypirobotics.com/measuring-rotation-and-acceleration-with-the-raspberry-pi/)
```python
#!/usr/bin/python
import smbus
import math
# Register
power_mgmt_1 = 0x6b
power_mgmt_2 = 0x6c
def read_byte(reg):
return bus.read_byte_data(address, reg)
def read_word(reg):
h = bus.read_byte_data(address, reg)
l = bus.read_byte_data(address, reg+1)
value = (h << 8) + l return value def read_word_2c(reg): val = read_word(reg) if (val >= 0x8000):
return -((65535 - val) + 1)
else:
return val
def dist(a,b):
return math.sqrt((a*a)+(b*b))
def get_y_rotation(x,y,z):
radians = math.atan2(x, dist(y,z))
return -math.degrees(radians)
def get_x_rotation(x,y,z):
radians = math.atan2(y, dist(x,z))
return math.degrees(radians)
bus = smbus.SMBus(1) # bus = smbus.SMBus(0) fuer Revision 1
address = 0x68 # via i2cdetect
# Aktivieren, um das Modul ansprechen zu koennen
bus.write_byte_data(address, power_mgmt_1, 0)
print "Gyroscope Sensor"
print "--------"
gyroscope_xout = read_word_2c(0x43)
gyroscope_yout = read_word_2c(0x45)
gyroscope_zout = read_word_2c(0x47)
print "gyroscope_xout: ", ("%5d" % gyroscope_xout), " scaled: ", (gyroscope_xout / 131)
print "gyroscope_yout: ", ("%5d" % gyroscope_yout), " scaled: ", (gyroscope_yout / 131)
print "gyroscope_zout: ", ("%5d" % gyroscope_zout), " scaled: ", (gyroscope_zout / 131)
print
print "Accelerometer Sensor"
print "---------------------"
acceleration_xout = read_word_2c(0x3b)
acceleration_yout = read_word_2c(0x3d)
acceleration_zout = read_word_2c(0x3f)
acceleration_xout_scaled = acceleration_xout / 16384.0
acceleration_yout_scaled = acceleration_yout / 16384.0
acceleration_zout_scaled = acceleration_zout / 16384.0
print "acceleration_xout: ", ("%6d" % acceleration_xout), " scaled: ", acceleration_xout_scaled
print "acceleration_yout: ", ("%6d" % acceleration_yout), " scaled: ", acceleration_yout_scaled
print "acceleration_zout: ", ("%6d" % acceleration_zout), " scaled: ", acceleration_zout_scaled
print "X Rotation: " , get_x_rotation(acceleration_xout_scaled, acceleration_yout_scaled, acceleration_zout_scaled)
print "Y Rotation: " , get_y_rotation(acceleration_xout_scaled, acceleration_yout_scaled, acceleration_zout_scaled)
Sending data to an HTTP server - get and post methods
Eclipse Mosquitto™ An open source MQTT broker Mosquitto is highly portable and available for a wide range of platforms. For Raspberry Pi Mosquitto is available through the main repository.
https://appcodelabs.com/introduction-to-iot-build-an-mqtt-server-using-raspberry-pi