About FAE_CA1

Hi, 1. When BMA253 is set to +/-2g full scale range, 1LSB for tap_th<4:0> in register 0x2B corresponds to 62.5mg. The pseudo code in the technical document uses 0x04 for tap_th<4:0> as an example. It means that the tap threshold is 62.5mg/LSB * 4LSB = 250mg. If you set tap_th<4:0> to 0x10 then the tap threshold will be 62.5mg/LSB * 16LSB = 1000mg = 1g.     The same applies to slope_th<7:0> in register 0x28. When BMA253 is set to +/-2g full scale range, 1LSB for slope_th<7:0> corresponds to 3.91mg. If you set slope_th<7:0> to 0x10 then the slope threshold will be 3.91mg/LSB * 16LSB = 62.56mg. Slope means the current acceleration value minus previous acceleration value, i.e. Delta ax_t = ax_t - ax_t-1 for x axis. If Delta ax_t is beyond the slope_th threshold for the amount of duration, then slope interrupt or any-motion interrupt will be generated. BMA253 single-tap and double-tap interrupts use Delta ax, ay, az as input. 2. When BMA253 bandwidth is set to 1000Hz, the sampling rate is 2000Hz which means the sample time is 0.5ms. Please see the attached Excel file for more information. Thanks. ... View more

Hi, Yes, BMA253 single-tap interrupt reacts to all x, y, and z axes. It doesn't matter which orientation BMA253 is at (flat, or vertical or any tilted angle) and which direction the single-tap motion is applied to BMA253 (along x/y/z axes or any direction in 3D space). If you set BMA253 full scale range to +/-16g for example, then sometimes small single-tap motion may not trigger the interrupt. So the full scale range of BMA253 is for the sensitivity of single-tap interrupt. Usually +/-2g full scale range should be sufficient. Thanks. ... View more

Hi, You set the bandwidth to 1KHz, but you changed the power mode from low power mode 1 to normal mode. Please follow the registers' configurations in the document of BMA253 single-tap. You should be able to see the single-tap interrupt signal. Thanks. ... View more

Hi, Please increase the bandwidth to 1KHz instead of 125Hz as shown in the technical document. Then you should be able to see the single-tap interrupt signal on INT1 pin. Thanks. ... View more

Hi, Thanks for your inquiry. BMA253 is not available for new designs. Please switch to BMA400. BMA400 has built-in auto wake-up and auto low-power interrupt feature. Please see the attached PDF files for more information. Thanks.   ... View more