201 Ultra Low Power Pedometer ASIC
201 : Ultra Low Power Pedometer ASIC
- Author: Dr. Sriram Anbalagan, SASTRA Deemed University
- Description: 656nW SPI pedometer with Alpha-Max Beta-Min magnitude and gait filter
- GitHub repository
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- Clock: 32768 Hz
Ultra Low Power Pedometer ASIC
Description
656nW pedometer ASIC using SPI accelerometer input with Alpha-Max Beta-Min magnitude estimation, 8-tap moving average filter and gait regularity filter.
How it works
Receives 48-bit SPI frames (16-bit X, Y, Z) from MEMS accelerometer (ADXL345). Computes magnitude using Alpha-Max Beta-Min algorithm. Detects steps using threshold crossing with hysteresis and gait regularity filter.
How to test
Connect ADXL345 accelerometer via SPI. Read step count via uo_out using byte_sel pin.
External hardware
ADXL345 or MPU6050 MEMS accelerometer
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | spi_clk | step_count[0] | step_detected |
| 1 | spi_mosi | step_count[1] | artifact_flag |
| 2 | spi_cs_n | step_count[2] | |
| 3 | byte_sel | step_count[3] | |
| 4 | step_count[4] | ||
| 5 | step_count[5] | ||
| 6 | step_count[6] | ||
| 7 | step_count[7] |