55 lines
1.8 KiB
C
55 lines
1.8 KiB
C
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#include <ch32fun.h>
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#include "lib_i2c.h"
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#include "sc7a20.h"
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// Initialization values for control registers, in reg-value pairs
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// Basically setup the unit to run, and enable 4D orientation detection
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// TODO: Make better comments and define values
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static const uint8_t i2c_registers[][2] = {
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{ SC7A20_CTRL_REG1, 0b01100111}, // 200Hz, XYZ enabled
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{ SC7A20_CTRL_REG2, 0b00000000}, // Setup filter to 0x00 ??
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{ SC7A20_CTRL_REG3, 0b00000000}, // INT1 off
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{ SC7A20_CTRL_REG4, 0b00001000}, // Block mode off,little-endian,2G,High-pres,self test off
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{ SC7A20_CTRL_REG5, 0b00000100}, // fifo off, D4D on INT1
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{ SC7A20_CTRL_REG6, 0x00}, // INT2 off
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{ SC7A20_INT2_CFG, 0b01111110}, // setup for movement detection
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{ SC7A20_INT2_THS, 0x28}, //
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{SC7A20_INT2_DURATION, 64}, //
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{ SC7A20_INT1_CFG, 0b01111110}, //
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{ SC7A20_INT1_THS, 0x28}, //
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{SC7A20_INT1_DURATION, 64}
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};
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void sc7a20_init()
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{
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// Setup acceleration readings
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// 2G range
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// bandwidth = 250Hz
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// High pass filter on (Slow compensation)
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// Turn off IRQ output pins
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// Orientation recognition in symmetrical mode
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// Hysteresis is set to ~ 16 counts
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// Theta blocking is set to 0b10
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for (uint8_t i = 0; i < sizeof(i2c_registers) / sizeof(i2c_registers[0]); i++) {
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uint8_t bytes[2] = {i2c_registers[i][0], i2c_registers[i][1]};
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i2c_sendBytes(I2C_TARGET, SC7A20_ADDRESS, bytes, 2);
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}
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}
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void sc7a20_get_readings(int16_t *x, int16_t *y, int16_t *z)
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{
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// We can tell the accelerometer to output in LE mode which makes this simple
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int16_t sensorData[3] = {0};
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i2c_sendByte(I2C_TARGET, SC7A20_ADDRESS, SC7A20_OUT_X_L | 0x80);
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i2c_readBytes(I2C_TARGET, SC7A20_ADDRESS, (u8*)sensorData, 6);
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// Lower byte is sent first
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*x = (int16_t)sensorData[0];
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*y = (int16_t)sensorData[1];
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*z = (int16_t)sensorData[2];
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}
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