CMPS14 - Tilt Compensated Magnetic Compass

Devantech

Overview

Offering equally impressive performance to the CMPS12, but also allowing background calibration to be disabled and operation with a fixed calibration profile.

Powered by the Bosch BNO080.

Introduction

The CMPS14 is Devantech's 5th generation tilt compensated compass. Employing a 3-axis magnetometer, a 3-axis gyro and a 3-axis accelerometer. At the core of the module is the superb BNO080 running algorithms to remove the errors caused by tilting of the PCB. The module also allows the calibration to be stopped and instead rely on a static calibration profile.
Power supply requirements are flexible, you can feed between 3.3 - 5v and the module draws a nominal 18mA of current. A choice of serial or I2C interfaces can be used for communication.

Mode selection and connections

Serial or I2C mode is easily selected with the state of the mode pin. Note the CMPS14 looks at the mode selection pin at power-up only.
For I2C the mode pin can be left open or pulled to the supply voltage, for serial mode the mode pin should be connected to 0v ground.

For details on use of the CMPS12 see the manufacturer's website (link below)

I2C commands in Linux

Install I2C on your computer and enable it. Then use for example the following simple commands:

~# i2cdetect -y 0
This command detects the devices (if you're using multiple devices, mention the number of devices which are connected in place of '0').

~# i2cset -y 0 xxxx 255
This simple command writes the byte value 255 to the I2C device at address xxxx hex on the i2c bus 0 (/dev/i2c-0).

~# i2cget -y 0 xxxx
This command reads a byte from an I2C device at address xxxx hex on the i2c bus 0 (/dev/i2c-0).

Testing CMP14 with Raspberry Pi 4

Raspberry Pi 4 has various pins such as VCC, GND, SDA and SCL .

Connect 5V Pin 2 or 5V Pin 4 at Pi to Vcc at CMP14 (red cable in image)
Connect GPIO 2 SDA (data) at Pi with SDA at CMP14 (green cable in image)
Connect GPIO 3 SCL (clock) with SCL at CMP14 (blue cable in image)
Connect Pin 6 GROUND at Pi with Ground at CMP14. (black cable in image)

Now follow the steps below in the command line of the Raspberry Pi 4:

sudo apt-get update

sudo apt-get upgrade

sudo raspi-config
enable I2C in the menu

i2cdetect -l

i2cdetect -y 1
The address of the CMP14 should be shown as HEX value such as 0x60. If it is not shown, then the CMP14 is probably disconnected. If disconnected, check connections and reboot the Pi.

i2cget -y 1 0x60 0x00
to read Software version
result: 0x06, which means 6.

i2cget -y 1 0x60 0x01
to read the Compass Bearing 8 bit, i.e. 0-255 for a full circle
result: 0x1F, which means 31

i2cget -y 1 0x60 0x06
to read the Magnetometer X axis (uTesla), 16 bit signed integer (register 0x06 high byte) Q point 4
result: 0xFE, which means 254

i2cget -y 1 0x60 0x16
to read the Gyroscope raw Z axis output, 16 bit signed integer (register 0x16 high byte)
result: 0x00, which means 0

i2cget -y 1 0x60 0xA1
to read the Baud rate
result: 0x06, which means OK

i2cget -y 1 0x60 0x26
to read the Gyroscope calibrated X axis output, 16 bit signed integer (register 0x25 high byte) Q point 9
result: 0x02, which means 2

PCB Board Dimensions

The following diagram shows the CMPS12 PCB dimensions and mounting hole positions.

Manufacturer's data

Technical Specification - link to the manufacturer

Accessories

4-Way split Cable with Molex connector, 30 cm in length

from ROBOT ELECTRONICS
Newest specification: 11/2014

EUR 3.97
plus EUR 5.95 shipping costs
Prices incl. VATEUR 3.34
plus EUR 5.00 shipping costs
Prices excl. VAT

Article no.: DEV-4-SPLIT-MOLEX
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CMPS10 Tower

from ROBOT ELECTRONICS
Newest specification: 09/2013

not available


Article no.: DEV-CMPS10-TOWER
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Product information for: CMPS14 - Tilt Compensated Magnetic Compass

Publishing date (date of last technical specification): 2019-02-26
Length: 25 mm
Width: 19 mm
Height: 4 mm
Weight: 3 g
Shipping weight: 100 g
Manufacturer: Devantech
Brand: ROBOT ELECTRONICS
Article number: DEV-CMPS14
Manufacturer's part number: CMPS14

The article CMPS14 - Tilt Compensated Magnetic Compass is listed in the following categories:

Sensors > Compass

CMPS14 - Tilt Compensated Magnetic Compass

from ROBOT ELECTRONICS
Newest specification: 02/2019

EUR 45.98
plus EUR 5.95 shipping costs
Prices incl. VATEUR 38.64
plus EUR 5.00 shipping costs
Prices excl. VAT

Article no.: DEV-CMPS14
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BNO055 - 9-Axis Orientation Sensor Module

from ROBOT ELECTRONICS
Newest specification: 03/2018

EUR 31.98
plus EUR 5.95 shipping costs
Prices incl. VATEUR 26.87
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Article no.: DEV-BNO055
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