Data sheet
BMA220
Page 12
BST-BMA220-DS003-08 | Revision 1.15 | August 2011 Bosch Sensortec
4.2 Setting registers
‘00’ ±2g 16 LSB / g 62.5mg / LSB
Orientation
recognition
‘01’ ±4g 8 LSB / g 125mg / LSB
‘10’ ±8g 4 LSB / g 0.25g / LSB
Gaming
‘11’ ±16g 2 LSB / g 0.5g / LSB
Shock vibration
detection
Bosch Sensortec
GmbH即使在工业产权的情况下也可以保留所有权利。我们保留所有处置权利,如复制和传递给第三方。博世和符号是
Robert Bosch GmbH,德国的注册商标。注意:本文档中的规格如有更改,恕不另行通知。
4.1.5软复位通过从软复位地址执行读取,可以将BMA220放入软复位状态。要将芯片恢复运行,必须从相同的内存地址
执行另一读。如果系统处于软复位模式,则读数返回值0xFF;否则它返回值0x00。请注意,用户编程的所有内部配置数据
将丢失。
4.1.6暂停模式BMA220可以放入暂停模式时。通过从暂停地址执行读取来容易地实现1μA以下的功耗。要将芯片恢复正
常模式操作,必须从相同的内存地址执行另一读。如果系统处于暂停模式,则读数返回值0xFF,否则返回值0x00。请注
意,在暂停期间,将禁用所有模拟模块的电源重置。暂停期间仅支持通过串行接口读取。
4.2.1加速度范围和灵敏度设置BMA220具有四种不同的范围设置,用于满量程加速范围。根据用例,始终应选择具有最
大分辨率的最低满量程范围。请参阅文献以了解,哪种全面加速范围,哪个敏感性或哪个分辨率是理想的。这可以通过
地址0x11(SPI)/
0x22(SPI)的寄存器位范围[1:0]进行配置。下表显示了具有相应比例和分辨率的范围位。表5:加速度分辨率
范围[1:0]全规模灵敏度解决例示例用例
趣卡社区(www.qukaa.com)
Data sheet
BMA220
Page 12
BST-BMA220-DS003-08 | Revision 1.15 | August 2011 Bosch Sensortec
© Bosch Sensortec GmbH reserve s all rights even in the event of industrial pro perty rights. We reserve all rights of disposal such as copying and passing on to
third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Note: Specifications within this document are subject to change without notice.
4.1.5 Soft-reset
The BMA220 can be put into a soft-reset state by performing a read from the soft-reset address.
To bring the chip back into operation, another read must be performed from the same memory
address. The reading returns value 0xFF if the system was in soft reset mode; otherwise it
returns value 0x00.
Please note that all internal configuration data programmed by the user will be lost.
4.1.6 Suspend mode
The BMA220 can be put into a suspend mode e.g. to easily achieve a power consumption
below 1μA by performing a read from the suspend address. To bring the chip back into normal
mode operation, another read must be performed from the same memory address. The reading
returns value 0xFF if the system was in suspend mode, otherwise it returns value 0x00.
Please note, that during suspend, all analog modules expect for power-on-reset will be disabled.
Only reads through the serial interface are supported during suspend.
4.2 Setting registers
4.2.1 Acceleration range and sensitivity setting
The BMA220 has four different range settings for the full scale acceleration range. In
dependence of the use case always the lowest full scale range with the maximum resolution
should be selected. Please refer to literature to find out, which full scale acceleration range,
which sensitivity or which resolution is the ideal one.
This can be configured via the register bits
range[1:0] at address 0x11 (SPI) / 0x22 (SPI).
The following table shows the range bits with corresponding scale and resolution.
Table 5: Acceleration resolution
range[1:0] Full Scale Sensitivity Resolution Example use case
‘00’ ±2g 16 LSB / g 62.5mg / LSB
Orientation
recognition
‘01’ ±4g 8 LSB / g 125mg / LSB
‘10’ ±8g 4 LSB / g 0.25g / LSB
Gaming
‘11’ ±16g 2 LSB / g 0.5g / LSB
Shock vibration
detection