accel.c 5.32 KB
Newer Older
1
2
3
#include <stdio.h>
#include <string.h>

4
#include "stm32f4xx_hal.h"
5

6
#include "nlr.h"
7
8
9
10
11
#include "misc.h"
#include "mpconfig.h"
#include "qstr.h"
#include "obj.h"
#include "runtime.h"
12
#include "i2c.h"
13
14
15
#include "accel.h"

#define MMA_ADDR (0x98)
16
17
18
19
#define MMA_REG_X (0)
#define MMA_REG_Y (1)
#define MMA_REG_Z (2)
#define MMA_REG_TILT (3)
20
#define MMA_REG_MODE (7)
21
#define MMA_AXIS_SIGNED_VALUE(i) (((i) & 0x3f) | ((i) & 0x20 ? (~0x1f) : 0))
22
23
24
25
26
27
28
29
30
31
32

void accel_init(void) {
    GPIO_InitTypeDef GPIO_InitStructure;

    // PB5 is connected to AVDD; pull high to enable MMA accel device
    GPIOB->BSRRH = GPIO_PIN_5; // turn off AVDD
    GPIO_InitStructure.Pin = GPIO_PIN_5;
    GPIO_InitStructure.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStructure.Speed = GPIO_SPEED_LOW;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStructure);
33
34
}

35
36
STATIC void accel_start(void) {
    // start the I2C bus
37
    i2c_init(&I2CHandle1);
38

39
40
41
42
43
    // turn off AVDD, wait 20ms, turn on AVDD, wait 20ms again
    GPIOB->BSRRH = GPIO_PIN_5; // turn off
    HAL_Delay(20);
    GPIOB->BSRRL = GPIO_PIN_5; // turn on
    HAL_Delay(20);
44
45
46
47
48

    HAL_StatusTypeDef status;

    //printf("IsDeviceReady\n");
    for (int i = 0; i < 10; i++) {
49
        status = HAL_I2C_IsDeviceReady(&I2CHandle1, MMA_ADDR, 10, 200);
50
51
52
53
54
55
56
57
58
        //printf("  got %d\n", status);
        if (status == HAL_OK) {
            break;
        }
    }

    //printf("MemWrite\n");
    uint8_t data[1];
    data[0] = 1; // active mode
59
    status = HAL_I2C_Mem_Write(&I2CHandle1, MMA_ADDR, MMA_REG_MODE, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
60
61
62
63
64
65
    //printf("  got %d\n", status);
}

/******************************************************************************/
/* Micro Python bindings                                                      */

66
67
#define NUM_AXIS (3)
#define FILT_DEPTH (4)
68

69
70
71
72
typedef struct _pyb_accel_obj_t {
    mp_obj_base_t base;
    int16_t buf[NUM_AXIS * FILT_DEPTH];
} pyb_accel_obj_t;
73

74
75
STATIC pyb_accel_obj_t pyb_accel_obj;

76
77
STATIC mp_obj_t pyb_accel_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
    // check arguments
Damien George's avatar
Damien George committed
78
    mp_arg_check_num(n_args, n_kw, 0, 0, false);
79
80
81

    // init accel object
    pyb_accel_obj.base.type = &pyb_accel_type;
82
    accel_start();
83
84
85
86

    return &pyb_accel_obj;
}

87
88
STATIC mp_obj_t read_axis(int axis) {
    uint8_t data[1];
89
    HAL_I2C_Mem_Read(&I2CHandle1, MMA_ADDR, axis, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
90
91
92
93
94
95
96
97
98
99
100
101
    return mp_obj_new_int(MMA_AXIS_SIGNED_VALUE(data[0]));
}

STATIC mp_obj_t pyb_accel_x(mp_obj_t self_in) {
    return read_axis(MMA_REG_X);
}

STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_x_obj, pyb_accel_x);

STATIC mp_obj_t pyb_accel_y(mp_obj_t self_in) {
    return read_axis(MMA_REG_Y);
}
102

103
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_y_obj, pyb_accel_y);
104

105
106
STATIC mp_obj_t pyb_accel_z(mp_obj_t self_in) {
    return read_axis(MMA_REG_Z);
107
108
}

109
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_z_obj, pyb_accel_z);
110

111
112
STATIC mp_obj_t pyb_accel_tilt(mp_obj_t self_in) {
    uint8_t data[1];
113
    HAL_I2C_Mem_Read(&I2CHandle1, MMA_ADDR, MMA_REG_TILT, I2C_MEMADD_SIZE_8BIT, data, 1, 200);
114
115
116
117
118
119
120
121
122
123
124
    return mp_obj_new_int(data[0]);
}

STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_tilt_obj, pyb_accel_tilt);

STATIC mp_obj_t pyb_accel_filtered_xyz(mp_obj_t self_in) {
    pyb_accel_obj_t *self = self_in;

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

    uint8_t data[NUM_AXIS];
125
    HAL_I2C_Mem_Read(&I2CHandle1, MMA_ADDR, MMA_REG_X, I2C_MEMADD_SIZE_8BIT, data, NUM_AXIS, 200);
126
127
128
129
130
131
132
133
134

    mp_obj_t tuple[NUM_AXIS];
    for (int i = 0; i < NUM_AXIS; i++) {
        self->buf[NUM_AXIS * (FILT_DEPTH - 1) + i] = MMA_AXIS_SIGNED_VALUE(data[i]);
        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);
135
136
    }

137
    return mp_obj_new_tuple(3, tuple);
138
139
}

140
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_accel_filtered_xyz_obj, pyb_accel_filtered_xyz);
141

142
STATIC mp_obj_t pyb_accel_read(mp_obj_t self_in, mp_obj_t reg) {
143
    uint8_t data[1];
144
    HAL_I2C_Mem_Read(&I2CHandle1, MMA_ADDR, mp_obj_get_int(reg), I2C_MEMADD_SIZE_8BIT, data, 1, 200);
145
146
147
    return mp_obj_new_int(data[0]);
}

148
MP_DEFINE_CONST_FUN_OBJ_2(pyb_accel_read_obj, pyb_accel_read);
149

150
STATIC mp_obj_t pyb_accel_write(mp_obj_t self_in, mp_obj_t reg, mp_obj_t val) {
151
152
    uint8_t data[1];
    data[0] = mp_obj_get_int(val);
153
    HAL_I2C_Mem_Write(&I2CHandle1, MMA_ADDR, mp_obj_get_int(reg), I2C_MEMADD_SIZE_8BIT, data, 1, 200);
154
155
156
    return mp_const_none;
}

157
MP_DEFINE_CONST_FUN_OBJ_3(pyb_accel_write_obj, pyb_accel_write);
158

159
160
161
162
163
164
165
166
STATIC const mp_map_elem_t pyb_accel_locals_dict_table[] = {
    { MP_OBJ_NEW_QSTR(MP_QSTR_x), (mp_obj_t)&pyb_accel_x_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_y), (mp_obj_t)&pyb_accel_y_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_z), (mp_obj_t)&pyb_accel_z_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_tilt), (mp_obj_t)&pyb_accel_tilt_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_filtered_xyz), (mp_obj_t)&pyb_accel_filtered_xyz_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&pyb_accel_read_obj },
    { MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&pyb_accel_write_obj },
167
168
};

169
170
STATIC MP_DEFINE_CONST_DICT(pyb_accel_locals_dict, pyb_accel_locals_dict_table);

171
const mp_obj_type_t pyb_accel_type = {
172
173
    { &mp_type_type },
    .name = MP_QSTR_Accel,
174
    .make_new = pyb_accel_make_new,
175
    .locals_dict = (mp_obj_t)&pyb_accel_locals_dict,
176
};