ports/stm32/accel.c - lite/micropython - Linaro Git Browser

 /*
  * This file is part of the MicroPython project, http://micropython.org/
  *
  * The MIT License (MIT)
  *
  * Copyright (c) 2013, 2014 Damien P. George
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include <stdio.h>
 #include <string.h>

 #include "py/mphal.h"
 #include "py/runtime.h"
 #include "pin.h"
 #include "i2c.h"
 #include "accel.h"

 #if MICROPY_HW_HAS_MMA7660 || MICROPY_HW_HAS_KXTJ3

 /// \moduleref pyb
 /// \class Accel - accelerometer control
 ///
 /// Accel is an object that controls the MMA7660 or the KXTJ3 accelerometer
 /// depending on one/two constant in mpconfigboard.h file of board project :
 /// #define MICROPY_HW_HAS_MMA7660      (1)
 /// #define MICROPY_HW_HAS_KXTJ3        (0) // not mandatory if equal to 0
 ///
 /// Example usage:
 ///
 ///     accel = pyb.Accel()
 ///     for i in range(10):
 ///         print(accel.x(), accel.y(), accel.z())
 ///
 /// Raw values are between -32 and 31 for -/+ 1.5G acceleration for MMA7660.
 /// Raw values are between -128 and 127 for -/+ 8G acceleration for KXTJ3.


 #define I2C_TIMEOUT_MS (50)

 #if MICROPY_HW_HAS_MMA7660

 #define ACCEL_ADDR                  (76)
 #define ACCEL_REG_X                 (0)
 #define ACCEL_REG_Y                 (1)
 #define ACCEL_REG_Z                 (2)
 #define ACCEL_REG_TILT              (3)
 #define ACCEL_REG_MODE              (7)
 #define ACCEL_AXIS_SIGNED_VALUE(i)  (((i) & 0x3f) | ((i) & 0x20 ? (~0x1f) : 0))

 #elif MICROPY_HW_HAS_KXTJ3

 #define ACCEL_ADDR                  (0x0f)
 #define ACCEL_REG_DCST_RESP         (0x0c)
 #define ACCEL_REG_WHO_AM_I          (0x0f)
 #define ACCEL_REG_X                 (0x07) // XOUT_H
 #define ACCEL_REG_Y                 (0x09) // YOUT_H
 #define ACCEL_REG_Z                 (0x0B) // ZOUT_H
 #define ACCEL_REG_CTRL_REG1         (0x1B)
 #define ACCEL_REG_CTRL_REG2         (0x1d)
 #define ACCEL_REG_CTRL_REG2         (0x1d)
 #define ACCEL_REG_DATA_CTRL_REG     (0x21)
 #define ACCEL_AXIS_SIGNED_VALUE(i)  (((i) & 0x7f) | ((i) & 0x80 ? (~0x7f) : 0))

 #endif

 void accel_init(void) {
     #if MICROPY_HW_HAS_MMA7660
     // PB5 is connected to AVDD; pull high to enable MMA accel device
     mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off AVDD
     mp_hal_pin_output(MICROPY_HW_MMA_AVDD_PIN);
     #endif
 }

 static void accel_start(void) {
     // start the I2C bus in master mode
     i2c_init(I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA, 400000, I2C_TIMEOUT_MS);

     #if MICROPY_HW_HAS_MMA7660

     // turn off AVDD, wait 30ms, turn on AVDD, wait 30ms again
     mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off
     mp_hal_delay_ms(30);
     mp_hal_pin_high(MICROPY_HW_MMA_AVDD_PIN); // turn on
     mp_hal_delay_ms(30);

     int ret;
     for (int i = 0; i < 4; i++) {
         ret = i2c_writeto(I2C1, ACCEL_ADDR, NULL, 0, true);
         if (ret == 0) {
             break;
         }
     }

     if (ret != 0) {
         mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("accelerometer not found"));
     }

     // set MMA to active mode
     uint8_t data[2] = {ACCEL_REG_MODE, 1}; // active mode
     i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);

     // wait for MMA to become active
     mp_hal_delay_ms(30);

     #elif MICROPY_HW_HAS_KXTJ3

     // readout WHO_AM_I register to check KXTJ3 device presence
     uint8_t data[2] = { ACCEL_REG_WHO_AM_I };
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
     i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
     if (data[0] != 0x35) {
         mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("accelerometer not found"));
     }

     // set operating mode (default: 8 bits, range +/-8G)
     data[0] = ACCEL_REG_CTRL_REG1;
     data[1] = 0x90;
     i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);
     // set dat output rates to 200Hz (LPF roll-over 10ms), idd=35uA
     data[0] = ACCEL_REG_DATA_CTRL_REG;
     data[1] = 0x04;
     i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);

     #endif
 }

 /******************************************************************************/
 /* MicroPython bindings                                                      */

 #define NUM_AXIS (3)
 #define FILT_DEPTH (4)

 typedef struct _pyb_accel_obj_t {
     mp_obj_base_t base;
     int16_t buf[NUM_AXIS * FILT_DEPTH];
 } pyb_accel_obj_t;

 static pyb_accel_obj_t pyb_accel_obj;

 /// \classmethod \constructor()
 /// Create and return an accelerometer object.
 ///
 /// Note: if you read accelerometer values immediately after creating this object
 /// you will get 0.  It takes around 20ms for the first sample to be ready, so,
 /// unless you have some other code between creating this object and reading its
 /// values, you should put a `pyb.delay(20)` after creating it.  For example:
 ///
 ///     accel = pyb.Accel()
 ///     pyb.delay(20)
 ///     print(accel.x())
 static mp_obj_t pyb_accel_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
     // check arguments
     mp_arg_check_num(n_args, n_kw, 0, 0, false);

     // init accel object
     pyb_accel_obj.base.type = &pyb_accel_type;
     accel_start();

     return MP_OBJ_FROM_PTR(&pyb_accel_obj);
 }

 static mp_obj_t read_axis(int axis) {
     uint8_t data[1] = { axis };
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
     i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
     return mp_obj_new_int(ACCEL_AXIS_SIGNED_VALUE(data[0]));
 }

 /// \method x()
 /// Get the x-axis value.
 static mp_obj_t pyb_accel_x(mp_obj_t self_in) {
     return read_axis(ACCEL_REG_X);
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_x_obj, pyb_accel_x);

 /// \method y()
 /// Get the y-axis value.
 static mp_obj_t pyb_accel_y(mp_obj_t self_in) {
     return read_axis(ACCEL_REG_Y);
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_y_obj, pyb_accel_y);

 /// \method z()
 /// Get the z-axis value.
 static mp_obj_t pyb_accel_z(mp_obj_t self_in) {
     return read_axis(ACCEL_REG_Z);
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_z_obj, pyb_accel_z);

 /// \method tilt()
 /// Get the tilt register.
 static mp_obj_t pyb_accel_tilt(mp_obj_t self_in) {
     #if MICROPY_HW_HAS_MMA7660
     uint8_t data[1] = { ACCEL_REG_TILT };
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
     i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
     return mp_obj_new_int(data[0]);
     #elif MICROPY_HW_HAS_KXTJ3
     /// No tilt like register with KXTJ3 accelerometer
     return 0;
     #endif
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_tilt_obj, pyb_accel_tilt);

 /// \method filtered_xyz()
 /// Get a 3-tuple of filtered x, y and z values.
 static mp_obj_t pyb_accel_filtered_xyz(mp_obj_t self_in) {
     pyb_accel_obj_t *self = MP_OBJ_TO_PTR(self_in);

     memmove(self->buf, self->buf + NUM_AXIS, NUM_AXIS * (FILT_DEPTH - 1) * sizeof(int16_t));

     #if MICROPY_HW_HAS_MMA7660
     const size_t DATA_SIZE = NUM_AXIS;
     const size_t DATA_STRIDE = 1;
     #elif MICROPY_HW_HAS_KXTJ3
     const size_t DATA_SIZE = 5;
     const size_t DATA_STRIDE = 2;
     #endif
     uint8_t data[DATA_SIZE];
     data[0] = ACCEL_REG_X;
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
     i2c_readfrom(I2C1, ACCEL_ADDR, data, DATA_SIZE, true);

     mp_obj_t tuple[NUM_AXIS];
     for (int i = 0; i < NUM_AXIS; i++) {
         self->buf[NUM_AXIS * (FILT_DEPTH - 1) + i] = ACCEL_AXIS_SIGNED_VALUE(data[i * DATA_STRIDE]);
         int32_t val = 0;
         for (int j = 0; j < FILT_DEPTH; j++) {
             val += self->buf[i + NUM_AXIS * j];
         }
         tuple[i] = mp_obj_new_int(val);
     }

     return mp_obj_new_tuple(3, tuple);
 }
 static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_filtered_xyz_obj, pyb_accel_filtered_xyz);

 static mp_obj_t pyb_accel_read(mp_obj_t self_in, mp_obj_t reg) {
     uint8_t data[1] = { mp_obj_get_int(reg) };
     i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
     i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
     return mp_obj_new_int(data[0]);
 }
 MP_DEFINE_CONST_FUN_OBJ_2(pyb_accel_read_obj, pyb_accel_read);

 static mp_obj_t pyb_accel_write(mp_obj_t self_in, mp_obj_t reg, mp_obj_t val) {
     uint8_t data[2] = { mp_obj_get_int(reg), mp_obj_get_int(val) };
     i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_3(pyb_accel_write_obj, pyb_accel_write);

 static const mp_rom_map_elem_t pyb_accel_locals_dict_table[] = {
     // TODO add init, deinit, and perhaps reset methods
     { MP_ROM_QSTR(MP_QSTR_x), MP_ROM_PTR(&pyb_accel_x_obj) },
     { MP_ROM_QSTR(MP_QSTR_y), MP_ROM_PTR(&pyb_accel_y_obj) },
     { MP_ROM_QSTR(MP_QSTR_z), MP_ROM_PTR(&pyb_accel_z_obj) },
     { MP_ROM_QSTR(MP_QSTR_tilt), MP_ROM_PTR(&pyb_accel_tilt_obj) },
     { MP_ROM_QSTR(MP_QSTR_filtered_xyz), MP_ROM_PTR(&pyb_accel_filtered_xyz_obj) },
     { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&pyb_accel_read_obj) },
     { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&pyb_accel_write_obj) },
 };

 static MP_DEFINE_CONST_DICT(pyb_accel_locals_dict, pyb_accel_locals_dict_table);

 MP_DEFINE_CONST_OBJ_TYPE(
     pyb_accel_type,
     MP_QSTR_Accel,
     MP_TYPE_FLAG_NONE,
     make_new, pyb_accel_make_new,
     locals_dict, &pyb_accel_locals_dict
     );

 #endif // MICROPY_HW_HAS_MMA7660 || MICROPY_HW_HAS_KXTJ3
	/*
	* This file is part of the MicroPython project, http://micropython.org/
	*
	* The MIT License (MIT)
	*
	* Copyright (c) 2013, 2014 Damien P. George
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include <stdio.h>
	#include <string.h>

	#include "py/mphal.h"
	#include "py/runtime.h"
	#include "pin.h"
	#include "i2c.h"
	#include "accel.h"

	#if MICROPY_HW_HAS_MMA7660 \|\| MICROPY_HW_HAS_KXTJ3

	/// \moduleref pyb
	/// \class Accel - accelerometer control
	///
	/// Accel is an object that controls the MMA7660 or the KXTJ3 accelerometer
	/// depending on one/two constant in mpconfigboard.h file of board project :
	/// #define MICROPY_HW_HAS_MMA7660 (1)
	/// #define MICROPY_HW_HAS_KXTJ3 (0) // not mandatory if equal to 0
	///
	/// Example usage:
	///
	/// accel = pyb.Accel()
	/// for i in range(10):
	/// print(accel.x(), accel.y(), accel.z())
	///
	/// Raw values are between -32 and 31 for -/+ 1.5G acceleration for MMA7660.
	/// Raw values are between -128 and 127 for -/+ 8G acceleration for KXTJ3.


	#define I2C_TIMEOUT_MS (50)

	#if MICROPY_HW_HAS_MMA7660

	#define ACCEL_ADDR (76)
	#define ACCEL_REG_X (0)
	#define ACCEL_REG_Y (1)
	#define ACCEL_REG_Z (2)
	#define ACCEL_REG_TILT (3)
	#define ACCEL_REG_MODE (7)
	#define ACCEL_AXIS_SIGNED_VALUE(i) (((i) & 0x3f) \| ((i) & 0x20 ? (~0x1f) : 0))

	#elif MICROPY_HW_HAS_KXTJ3

	#define ACCEL_ADDR (0x0f)
	#define ACCEL_REG_DCST_RESP (0x0c)
	#define ACCEL_REG_WHO_AM_I (0x0f)
	#define ACCEL_REG_X (0x07) // XOUT_H
	#define ACCEL_REG_Y (0x09) // YOUT_H
	#define ACCEL_REG_Z (0x0B) // ZOUT_H
	#define ACCEL_REG_CTRL_REG1 (0x1B)
	#define ACCEL_REG_CTRL_REG2 (0x1d)
	#define ACCEL_REG_CTRL_REG2 (0x1d)
	#define ACCEL_REG_DATA_CTRL_REG (0x21)
	#define ACCEL_AXIS_SIGNED_VALUE(i) (((i) & 0x7f) \| ((i) & 0x80 ? (~0x7f) : 0))

	#endif

	void accel_init(void) {
	#if MICROPY_HW_HAS_MMA7660
	// PB5 is connected to AVDD; pull high to enable MMA accel device
	mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off AVDD
	mp_hal_pin_output(MICROPY_HW_MMA_AVDD_PIN);
	#endif
	}

	static void accel_start(void) {
	// start the I2C bus in master mode
	i2c_init(I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA, 400000, I2C_TIMEOUT_MS);

	#if MICROPY_HW_HAS_MMA7660

	// turn off AVDD, wait 30ms, turn on AVDD, wait 30ms again
	mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off
	mp_hal_delay_ms(30);
	mp_hal_pin_high(MICROPY_HW_MMA_AVDD_PIN); // turn on
	mp_hal_delay_ms(30);

	int ret;
	for (int i = 0; i < 4; i++) {
	ret = i2c_writeto(I2C1, ACCEL_ADDR, NULL, 0, true);
	if (ret == 0) {
	break;
	}
	}

	if (ret != 0) {
	mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("accelerometer not found"));
	}

	// set MMA to active mode
	uint8_t data[2] = {ACCEL_REG_MODE, 1}; // active mode
	i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);

	// wait for MMA to become active
	mp_hal_delay_ms(30);

	#elif MICROPY_HW_HAS_KXTJ3

	// readout WHO_AM_I register to check KXTJ3 device presence
	uint8_t data[2] = { ACCEL_REG_WHO_AM_I };
	i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
	i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
	if (data[0] != 0x35) {
	mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("accelerometer not found"));
	}

	// set operating mode (default: 8 bits, range +/-8G)
	data[0] = ACCEL_REG_CTRL_REG1;
	data[1] = 0x90;
	i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);
	// set dat output rates to 200Hz (LPF roll-over 10ms), idd=35uA
	data[0] = ACCEL_REG_DATA_CTRL_REG;
	data[1] = 0x04;
	i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);

	#endif
	}

	/******************************************************************************/
	/* MicroPython bindings */

	#define NUM_AXIS (3)
	#define FILT_DEPTH (4)

	typedef struct _pyb_accel_obj_t {
	mp_obj_base_t base;
	int16_t buf[NUM_AXIS * FILT_DEPTH];
	} pyb_accel_obj_t;

	static pyb_accel_obj_t pyb_accel_obj;

	/// \classmethod \constructor()
	/// Create and return an accelerometer object.
	///
	/// Note: if you read accelerometer values immediately after creating this object
	/// you will get 0. It takes around 20ms for the first sample to be ready, so,
	/// unless you have some other code between creating this object and reading its
	/// values, you should put a `pyb.delay(20)` after creating it. For example:
	///
	/// accel = pyb.Accel()
	/// pyb.delay(20)
	/// print(accel.x())
	static mp_obj_t pyb_accel_make_new(const mp_obj_type_t type, size_t n_args, size_t n_kw, const mp_obj_t args) {
	// check arguments
	mp_arg_check_num(n_args, n_kw, 0, 0, false);

	// init accel object
	pyb_accel_obj.base.type = &pyb_accel_type;
	accel_start();

	return MP_OBJ_FROM_PTR(&pyb_accel_obj);
	}

	static mp_obj_t read_axis(int axis) {
	uint8_t data[1] = { axis };
	i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
	i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
	return mp_obj_new_int(ACCEL_AXIS_SIGNED_VALUE(data[0]));
	}

	/// \method x()
	/// Get the x-axis value.
	static mp_obj_t pyb_accel_x(mp_obj_t self_in) {
	return read_axis(ACCEL_REG_X);
	}
	static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_x_obj, pyb_accel_x);

	/// \method y()
	/// Get the y-axis value.
	static mp_obj_t pyb_accel_y(mp_obj_t self_in) {
	return read_axis(ACCEL_REG_Y);
	}
	static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_y_obj, pyb_accel_y);

	/// \method z()
	/// Get the z-axis value.
	static mp_obj_t pyb_accel_z(mp_obj_t self_in) {
	return read_axis(ACCEL_REG_Z);
	}
	static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_z_obj, pyb_accel_z);

	/// \method tilt()
	/// Get the tilt register.
	static mp_obj_t pyb_accel_tilt(mp_obj_t self_in) {
	#if MICROPY_HW_HAS_MMA7660
	uint8_t data[1] = { ACCEL_REG_TILT };
	i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
	i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
	return mp_obj_new_int(data[0]);
	#elif MICROPY_HW_HAS_KXTJ3
	/// No tilt like register with KXTJ3 accelerometer
	return 0;
	#endif
	}
	static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_tilt_obj, pyb_accel_tilt);

	/// \method filtered_xyz()
	/// Get a 3-tuple of filtered x, y and z values.
	static mp_obj_t pyb_accel_filtered_xyz(mp_obj_t self_in) {
	pyb_accel_obj_t *self = MP_OBJ_TO_PTR(self_in);

	memmove(self->buf, self->buf + NUM_AXIS, NUM_AXIS * (FILT_DEPTH - 1) * sizeof(int16_t));

	#if MICROPY_HW_HAS_MMA7660
	const size_t DATA_SIZE = NUM_AXIS;
	const size_t DATA_STRIDE = 1;
	#elif MICROPY_HW_HAS_KXTJ3
	const size_t DATA_SIZE = 5;
	const size_t DATA_STRIDE = 2;
	#endif
	uint8_t data[DATA_SIZE];
	data[0] = ACCEL_REG_X;
	i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
	i2c_readfrom(I2C1, ACCEL_ADDR, data, DATA_SIZE, true);

	mp_obj_t tuple[NUM_AXIS];
	for (int i = 0; i < NUM_AXIS; i++) {
	self->buf[NUM_AXIS * (FILT_DEPTH - 1) + i] = ACCEL_AXIS_SIGNED_VALUE(data[i * DATA_STRIDE]);
	int32_t val = 0;
	for (int j = 0; j < FILT_DEPTH; j++) {
	val += self->buf[i + NUM_AXIS * j];
	}
	tuple[i] = mp_obj_new_int(val);
	}

	return mp_obj_new_tuple(3, tuple);
	}
	static MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_filtered_xyz_obj, pyb_accel_filtered_xyz);

	static mp_obj_t pyb_accel_read(mp_obj_t self_in, mp_obj_t reg) {
	uint8_t data[1] = { mp_obj_get_int(reg) };
	i2c_writeto(I2C1, ACCEL_ADDR, data, 1, false);
	i2c_readfrom(I2C1, ACCEL_ADDR, data, 1, true);
	return mp_obj_new_int(data[0]);
	}
	MP_DEFINE_CONST_FUN_OBJ_2(pyb_accel_read_obj, pyb_accel_read);

	static mp_obj_t pyb_accel_write(mp_obj_t self_in, mp_obj_t reg, mp_obj_t val) {
	uint8_t data[2] = { mp_obj_get_int(reg), mp_obj_get_int(val) };
	i2c_writeto(I2C1, ACCEL_ADDR, data, 2, true);
	return mp_const_none;
	}
	MP_DEFINE_CONST_FUN_OBJ_3(pyb_accel_write_obj, pyb_accel_write);

	static const mp_rom_map_elem_t pyb_accel_locals_dict_table[] = {
	// TODO add init, deinit, and perhaps reset methods
	{ MP_ROM_QSTR(MP_QSTR_x), MP_ROM_PTR(&pyb_accel_x_obj) },
	{ MP_ROM_QSTR(MP_QSTR_y), MP_ROM_PTR(&pyb_accel_y_obj) },
	{ MP_ROM_QSTR(MP_QSTR_z), MP_ROM_PTR(&pyb_accel_z_obj) },
	{ MP_ROM_QSTR(MP_QSTR_tilt), MP_ROM_PTR(&pyb_accel_tilt_obj) },
	{ MP_ROM_QSTR(MP_QSTR_filtered_xyz), MP_ROM_PTR(&pyb_accel_filtered_xyz_obj) },
	{ MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&pyb_accel_read_obj) },
	{ MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&pyb_accel_write_obj) },
	};

	static MP_DEFINE_CONST_DICT(pyb_accel_locals_dict, pyb_accel_locals_dict_table);

	MP_DEFINE_CONST_OBJ_TYPE(
	pyb_accel_type,
	MP_QSTR_Accel,
	MP_TYPE_FLAG_NONE,
	make_new, pyb_accel_make_new,
	locals_dict, &pyb_accel_locals_dict
	);

	#endif // MICROPY_HW_HAS_MMA7660 \|\| MICROPY_HW_HAS_KXTJ3