Centre for Microcomputer Applications

Centre for Microcomputer Applications

3-Axis acceleration sensor ML29s

User’s Guide


Short description

The 3-Axis Acceleration sensor ML29s measures acceleration along 3 axes x, y, and z. The sensor has 3 measurement ranges: - 2 .. 2 g (default), -4 .. 4 g, and -8 .. 8 g. The sensor gives values on a g scale, whereby one g is the acceleration due to gravity at the Earth’s surface, 9.81 m/s2.

The sensing element of the sensor is mounted inside the air box.

The directions of the axes are marked on the sensor’s label.Holding the sensor in the position shown on the picture should give the following values of the measured component accelerations:

x-component = 0 g

y-component = 0 g

z-component = -1g

The net acceleration is calculated as the square root of the sum of the squares of the componentaccelerations.

The 3-Axis Acceleration sensor is an I2C digital sensor, which gives calibrated values of the measured quantity. This sensor can only be connected to special interfaces that support I2C digital sensors like the CMA MoLab interface. The sensor cable needed to connect the sensor to an interface is not supplied with the sensor (sensor cables are supplied with interfaces).

Sensor specifications

The 3-Axis Acceleration sensor ML29s is a digital sensor that converts the measured acceleration valuesto digital values via 10-bit analog-to-digital conversion. The resolution of the senor is ±0.004g for the range between - 2 to 2 g, ±0.008g for the range between - 4 to 4 g and ±0.016g for the range between -8 to 8 g.

Collecting data

This 3-Axis Acceleration sensor works only with specific interfaces. The sensor will be automatically detected when connected to such an interface. For detailed information about measurements with sensors consult the User Manuals of the interface and the Coach 6 software.


The 3-Axis Acceleration sensor is supplied with a factory calibration in g values. The Coach 6 program allows selecting the measuring range of the sensorand shifting the sensor calibration if needed. The Set to zero option in Coach 6 can be used to adjust the zero point and the Set to value option can be used to adjust the measured value to another value. This can be done independent for each of 3 axes.

Since the 3-Axis Accelerometer is equivalent to three accelerometers, youcan use just one channel of it to study acceleration along a single axis. Mountthe accelerometer so that a particular axis is in the direction of interest and monitorjust that channel.

Suggested experiments

The 3-Axis Acceleration sensor can be used to study, e.g.:

  • Bungee jump.
  • Pendulum motion.
  • Changes in acceleration in a golf swing.
  • Explanation of free fall,
  • Tilting of an object.

Also the sensor can be used in any experiment that uses only one or two axes, examples include:

  • Measure the acceleration of dynamics carts as they roll down inclines.
  • Measure the acceleration of dynamics carts as a force is applied to them.
  • Measure acceleration of elevators, remote-controlled cars, bicycles, or automobiles.

Triaxial Acceletaion 3 1 jpg

Figure 1.Measuring the acceleration of a dynamic cart as a force is applied.
When used in combination with a Force sensor it is possible to monitor both force and acceleration at the same time.

Technical Specifications

Sensor kind / Digital
on-sensor digital conversion
(up to 10-bits resolution, communication via I2C)
Measuring range / - 2 to 2 g (default)
- 4 to 4 g
- 8 to 8 g
Resolution / ±0.004g (range - 2 to 2 g)
±0.008g (range - 4 to 4 g)
±0.016g (range -8 to 8 g)
Accuracy / Typical, ± 0.35g (sampling rate <25Hz)
Zero-g Offset: ± 0.06g at 25°C (sampling rate <500Hz)
Nonlinearity: ± 0.5% of full range (±8g) (sampling rate <25Hz)
Cross Axis Sensitivity: 2% (Relative contribution between 3axes)
sampling rate /
500 Hz
Response / Acceleration data refresh rate (all axes) of sensing element: 3000Hz
Dimensions / Housing: 37x18x16 mm (WxDxH)
Connection / 5-pins mini jack plug


The 3-Axis Acceleration sensor ML29s is warranted to be free from defects in materials and workmanship for a period of 12 months from the date of purchase provided that it has been used under normal laboratory conditions. This warranty does not apply if the sensor has been damaged by accident or misuse.

Note:This product is to be used for educational purposes only. It is not appropriate for industrial, medical, research, or commercial applications.

Rev. 17/11/2011

ML29s3-Axis Acceleration Sensor User’s Guide|1