Where do you want to go ? Find east, west, south, north with this sensor when in horizontal position. See this videoclip for a demo of the Orient v1.1.
Application examples
- Orientation of a physical object that's horizontally stable.
- Allow your robot or toy car to know where it's being directed. Combine with GForce2D-2, and ReachClose to detect approaches to and/or impacts with walls and what have you.
- A wireless Wi-microDig is recommended in all cases.
Technical specifications
Product Orient sensor Version 2.0 (October 2005) Sensing parameter single-axis orientation Sensing method uses hall effect to detect the earth's magnetic field Range 360° (NESW) Resolution 1.4° Accuracy 4° (after calibration) Response time 102 ms Calibration degree bearing Voltage (use 5 V power supply) 7-bit MIDI value (use 'no processing' preset) 0 north 0.00 0 90 east 1.25 32 180 south 2.50 64 270 west 3.75 96 358.6/TD> 5.00 127 Power supply 4.75 to 5.25 V DC, 20 mA Operating temperature -20 to 50 °C (-29 to 10 °F) Sensor dimensions 33 x 50 x 11 mm (1.2 x 2.0 x 0.43 inch), incl. four 3.18 mm (0.125 inch) mounting holes spaced 25.4 x 40.6 mm (1.00 x 1.60 inch) apart Weight 30 g (1.1 oz), incl. cable Cable 1.0 m (39 inch), shielded, red wire = power, black wire = ground, white wire = sensor output, maximum extension 30 m (98 ft) Connector male plug with 3 pins in a row spaced 2.54 mm (0.100 inch) Application notes
- Calibration needs to be done only once per location - the calibration data is stored in non-volatile EEPROM memory. You do not need to re-calibrate every time the module is powered up, unless you change your location. The module has already been calibrated in our workshop for our location, which is 67 degrees (angle from the equator). If your location is close to this, you may like to try the compass without re-calibrating at all. Compass module orientation to produce 0 degrees reading: the front side (opposite side where switch and cable are located) must point north. The tact switch is used to calibrate the compass. To calibrate the compass you only have to press the switch for each of the four major compass points North, East, South and West. The compass points can be set in any order, but all four points must be calibrated. For example:
1. Set the compass module flat, pointing North. Press and release the switch.
2. Set the compass module flat, pointing East. Press and release the switch.
3. Set the compass module flat, pointing South. Press and release the switch.
4. Set the compass module flat, pointing West. Press and release the switch.
- Place horizontal (calibration may be necessary to obtain correct output values) to avoid measuring the vertical component of the earth's magnetic field and hence erroneous sensor output. The angle of the earth's field is not horizontal, it dives into the ground at an angle which varies according to location. It is this which produces an inherent error in the reading, and makes calibration of the compass required at the location where it is to be operated. After calibration you can expect 3-4° accuracy if you keep it horizontal. Not recommended for placement on the hand unless the hand movements are very steady and only involve rotation in the horizontal plane.
- When using horizontally, motions other than rotation around the vertical axis including vibration may distort sensor output.
- Any magnetic materials or fields in vicinity may distort sensor output.
- Can also be used vertically to detect the angle of the earth's magnetic field wrt. the horizontal plane.
- Warning ! Make sure the sensor is plugged into the Digitizer with the red wire connected to power. Reversing the plug may cause damage to the sensor.
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