Study on the feasibility of gravity induction game
A. Gravity sensing components in mobile phones
Many people know that the mobile phone has the function of gravity sensor, but what is gravity sensor is not very understanding. Gravity sensor is not a camera, people know how many pixels, not touch screen, people know whether it is capacitive screen or resistive screen, gravity sensor like shrouded in the fog of the valley, it is difficult to explore. The gravity sensing components are described in detail below.
component 1: Accelerometer
to understand the accelerometer, you first need to know what the accelerometer is. The accelerometer is essentially an electronic component that detects the size and direction of the acceleration that the phone is subjected to, while the cell phone is only subjected to gravitational acceleration when it is resting . So many people call the accelerometer function also called the gravity sensor function. The specific parameters and applications of an accelerometer are listed below:
Accelerometer Model: mma7660
Manufacturer: Freescale
? Digital Output (i²c)
? Integration 3 Axis ±1.5 g MEMS sensors and CMOS interface Controller in the same package
? Configurable data output rate:1-120 Secondary sampling / sec
? Automatic wake-up / Auto sleep function to reduce power consumption
? Direction Detection: Landscape / portrait, front / Reverse identification
? vibration identification and pulse recognition
? reliable design, high shock resistance ( ( g)
Typical applications:
? Mobile /PMP/PDA : Image stability , text scrolling, mobile dialing, click Mute
? hard disk drive (HDD): Free Fall Detection
? laptop: Free fall detection, anti-theft
? Step-Count device
? motion sensing, fault recorder
From the data, the accelerator is the core component of the current mobile device gravity sensing function, it can sense the size and direction of the acceleration received by the mobile phone, that is, the accelerometer is the internal measurement components in all directions of the force to obtain results. But whether the accelerometer is the mobile phone gravity sensor all the components, in fact, not really, the following describes the mobile phone gravity sensor function of the other 2 components.
Component 2: Gyroscope
When it comes to gyroscopes, a lot of people first impressions will feel very ridiculous, how can there be a gyro in the phone, in fact, it is not so. A gyroscope is an internal gyroscope, whose axis is always parallel to the initial direction due to the gyro effect, so that the actual direction can be calculated by deviations from the initial direction. The gyroscope in the cell phone is actually a very sophisticated chip with ultra-tiny tops inside. The angular motion detection device of one or two axes which is orthogonal to the rotation axis by the angular momentum sensitive shell relative to the inertia space of the high-speed rotating body. The same function of the angular motion detection device made by other principles is also called a gyroscope. The specific parameters of a gyroscope are listed below:
Model: Lpr550al
Product data:
manufacturer : STMicroelectronics
Product Type : gyroscopes
RoHS: is a
Sensing Shaft : Dual
Sensitivity : 0.5 mv/deg/s
Output Type : Analog-voltage
Supply Current : 6.8 MA
Package / Box : LGA-16
Package : Tray
Maximum operating temperature : +-C
Minimum operating temperature :-+ C
supply voltage (max.) : 3.6 V
supply voltage (minimum value) : 2.7 V
Package: TRAY
Description: lpr550al Series Dual Axis Pitch and Roll ±+ ° / s Analog Gyroscope LGA-16
Application of gyroscope Sensors:
1. mobile phone & PDAswith camera: stable image
2. camera and Camera: image stabilization
3. game console: attitude recognition
4. Robotic technology : Flip Detection, Measurement of inclination
5. Automotive Electronics : unsafe factors, active / Passive Safety devices
6.GPS navigation system : navigation Support, Projection Positioning Technology
7. computer : gesture Recognition
From the data, gyro measurement is the reference standard is the inner middle in the vertical direction with the ground to rotate the gyro. The result is obtained by the angle between the device and the gyro.
Component 3: magnetometer
A magnetometer is a test of the strength and direction of a magnetic field. The principle of magnetometer is the simplest compass involved in middle school physics. The following is a list of the specific parameters of a common magnetometer:
product model: three-axis magnetometer MAG3110
Manufacturer: Freescale
SCL Clock: 400KHz Max
Write Address: 0x1C
Read Address: 0x1D
Write timing: i²c start bit--MAG3110 write address--target register address--write data--stop bit
Read time series: i²c start bit--MAG3110 write address--target register address--repeat start bit-- MAG3110 Read address--Accept data--stop bit
Summary: The gyroscope's strength lies in measuring the rotational motion of the device itself. Better at the device's own motion. However, the location of the device cannot be determined.
The accelerometer's strength lies in measuring the force of the device. better at the movement of the device relative to the external reference ( e.g., ground ) . But it is not accurate to measure the position of the device relative to the ground.
The magnetometer's strength lies in locating the device. It can measure the angle between the current equipment and the four directions.
gyroscope detection of the rotation angle of the equipment is instantaneous and very accurate, to meet a number of applications requiring high resolution and rapid response, such as FPS game aimed at. And the gyroscope with accelerometers can be navigated without satellites and networks, a classic gyroscope application. Accelerometers can be used in applications with fixed gravity reference coordinate systems, linear or oblique motions, but rotational motion is limited to a certain range. When dealing with both linear and rotational motions, it is necessary to combine the acceleration with the gyroscope meter. If you still want the equipment to move without losing direction, add the magnetometer.
two. Research on the application function of the current mainstream mobile phone's gravity sensor
introduced the current mobile phone gravity sensor equipment, but also feel the current electronic equipment, the powerful function, whether our hands of the mobile phone can achieve the above functions, the answer is negative. As we all know, the technology of electronic products is very difficult, take the gyroscope as an example, its purchase path is: The United States ADI Inc. TI company ST company Russia Fizoptika Norwegian Sensonor Corp. Japan Silicon BEI Murata, USA EPSON United States CROSSBOWKVH Some universities and research institutes in China are also developing and producing some gyroscopes. From the data, the main manufacturers of these high-tech components are still foreign high-tech companies, and mainly used in high-tech industries, a mobile phone equipped with a high-tech equipment for space flight, which is impossible anyway. So due to the cost of production and so on, the electronic components in our mobile phones are not able to achieve these effects as actually described above.
And the hardware is limited by the software, the hardware is good, the driver can not realize these functions is also in vain, below I will introduce the current common mainstream mobile phone gravity sensor can realize the function.
to domestic manufacturers M8 For example (its hardware is configured enough to iphone generation contend, although somewhat old, but the principle is unchanged), the easiest to understand gravity induction theory for the use of piezoelectric sensors , using the piezoelectric effect to measure the inner weight ( actually very light ...) the gravity of the orthogonal two-direction of the split force size , You can determine the horizontal direction . DirectInput provides the most advanced interface for a variety of input devices, such as joysticks, helmets, multi-button mice, and force feedback devices, by directly cooperating with the device driver . DirectInput bypasses the Windows messaging system to provide the best performance. There are four basic types of effects: continuous force, tilt effect, cycle effect, and condition. Continuous force is a force that does not change strength in a single direction. The tilt effect is a continuous force that changes linearly with time. The cycle effect is repeated over a given axis, and the magnitude or strength of the force is defined by the period effect. The condition is the effect that responds to the interaction between the user and the joystick. This effect is similar to a spring, the farther the joystick pushes in one direction, the stronger the rebound force.
The above information shows that the current mainstream mobile phones are still supported by the two-axis induction (of course, do not rule out new high-end models and iphone 's three axes, but after all is a handful). Therefore, its realization of the function is greatly limited, but also can be understood as only the function of the horizontal state of the plane positioning, that is, the tilt of the upper and lower left and right and erect when the left and right (in theory should also be able to) sway, which greatly limits the game function of the application.
A study on the feasibility of gravity induction game-end