2 * Copyright © 2012 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 #include <ao_mpu6000.h>
22 static uint8_t ao_mpu6000_wake;
23 static uint8_t ao_mpu6000_configured;
26 ao_mpu6000_write(uint8_t addr, uint8_t *data, uint8_t len)
28 ao_i2c_get(AO_MPU6000_I2C_INDEX);
29 ao_i2c_start(AO_MPU6000_I2C_INDEX, MPU6000_ADDR_WRITE);
30 ao_i2c_send(&addr, 1, AO_MPU6000_I2C_INDEX, FALSE);
31 ao_i2c_send(data, len, AO_MPU6000_I2C_INDEX, TRUE);
32 ao_i2c_put(AO_MPU6000_I2C_INDEX);
36 ao_mpu6000_reg_write(uint8_t addr, uint8_t value)
38 uint8_t d[2] = { addr, value };
39 ao_i2c_get(AO_MPU6000_I2C_INDEX);
40 ao_i2c_start(AO_MPU6000_I2C_INDEX, MPU6000_ADDR_WRITE);
41 ao_i2c_send(d, 2, AO_MPU6000_I2C_INDEX, TRUE);
42 ao_i2c_put(AO_MPU6000_I2C_INDEX);
46 ao_mpu6000_read(uint8_t addr, void *data, uint8_t len)
48 ao_i2c_get(AO_MPU6000_I2C_INDEX);
49 ao_i2c_start(AO_MPU6000_I2C_INDEX, MPU6000_ADDR_WRITE);
50 ao_i2c_send(&addr, 1, AO_MPU6000_I2C_INDEX, FALSE);
51 ao_i2c_start(AO_MPU6000_I2C_INDEX, MPU6000_ADDR_READ);
52 ao_i2c_recv(data, len, AO_MPU6000_I2C_INDEX, TRUE);
53 ao_i2c_put(AO_MPU6000_I2C_INDEX);
57 ao_mpu6000_reg_read(uint8_t addr)
60 ao_i2c_get(AO_MPU6000_I2C_INDEX);
61 ao_i2c_start(AO_MPU6000_I2C_INDEX, MPU6000_ADDR_WRITE);
62 ao_i2c_send(&addr, 1, AO_MPU6000_I2C_INDEX, FALSE);
63 ao_i2c_start(AO_MPU6000_I2C_INDEX, MPU6000_ADDR_READ);
64 ao_i2c_recv(&value, 1, AO_MPU6000_I2C_INDEX, TRUE);
65 ao_i2c_put(AO_MPU6000_I2C_INDEX);
70 ao_mpu6000_sample(struct ao_mpu6000_sample *sample)
72 uint16_t *d = (uint16_t *) sample;
73 int i = sizeof (*sample) / 2;
75 ao_mpu6000_read(MPU6000_ACCEL_XOUT_H, sample, sizeof (*sample));
76 /* byte swap (sigh) */
79 *d++ = (t >> 8) | (t << 8);
83 #define G 981 /* in cm/s² */
85 static int16_t /* cm/s² */
86 ao_mpu6000_accel(int16_t v)
88 return (int16_t) ((v * (int32_t) (16.0 * 980.665 + 0.5)) / 32767);
91 static int16_t /* deg*10/s */
92 ao_mpu6000_gyro(int16_t v)
94 return (int16_t) ((v * (int32_t) 20000) / 32767);
98 ao_mpu6000_accel_check(int16_t normal, int16_t test, char *which)
100 int16_t diff = test - normal;
102 if (diff < MPU6000_ST_ACCEL(16) / 2) {
103 printf ("%s accel self test value too small (normal %d, test %d)\n",
104 which, normal, test);
107 if (diff > MPU6000_ST_ACCEL(16) * 2) {
108 printf ("%s accel self test value too large (normal %d, test %d)\n",
109 which, normal, test);
116 ao_mpu6000_gyro_check(int16_t normal, int16_t test, char *which)
118 int16_t diff = test - normal;
122 if (diff < MPU6000_ST_GYRO(2000) / 2) {
123 printf ("%s gyro self test value too small (normal %d, test %d)\n",
124 which, normal, test);
127 if (diff > MPU6000_ST_GYRO(2000) * 2) {
128 printf ("%s gyro self test value too large (normal %d, test %d)\n",
129 which, normal, test);
136 ao_mpu6000_setup(void)
138 struct ao_mpu6000_sample normal_mode, test_mode;
141 if (ao_mpu6000_configured)
144 /* Reset the whole chip */
146 ao_mpu6000_reg_write(MPU6000_PWR_MGMT_1,
147 (1 << MPU6000_PWR_MGMT_1_DEVICE_RESET));
148 while (ao_mpu6000_reg_read(MPU6000_PWR_MGMT_1) &
149 (1 << MPU6000_PWR_MGMT_1_DEVICE_RESET))
152 /* Reset signal conditioning */
153 ao_mpu6000_reg_write(MPU6000_USER_CONTROL,
154 (0 << MPU6000_USER_CONTROL_FIFO_EN) |
155 (0 << MPU6000_USER_CONTROL_I2C_MST_EN) |
156 (0 << MPU6000_USER_CONTROL_I2C_IF_DIS) |
157 (0 << MPU6000_USER_CONTROL_FIFO_RESET) |
158 (0 << MPU6000_USER_CONTROL_I2C_MST_RESET) |
159 (1 << MPU6000_USER_CONTROL_SIG_COND_RESET));
161 while (ao_mpu6000_reg_read(MPU6000_USER_CONTROL) & (1 << MPU6000_USER_CONTROL_SIG_COND_RESET))
164 /* Reset signal paths */
165 ao_mpu6000_reg_write(MPU6000_SIGNAL_PATH_RESET,
166 (1 << MPU6000_SIGNAL_PATH_RESET_GYRO_RESET) |
167 (1 << MPU6000_SIGNAL_PATH_RESET_ACCEL_RESET) |
168 (1 << MPU6000_SIGNAL_PATH_RESET_TEMP_RESET));
170 ao_mpu6000_reg_write(MPU6000_SIGNAL_PATH_RESET,
171 (0 << MPU6000_SIGNAL_PATH_RESET_GYRO_RESET) |
172 (0 << MPU6000_SIGNAL_PATH_RESET_ACCEL_RESET) |
173 (0 << MPU6000_SIGNAL_PATH_RESET_TEMP_RESET));
175 /* Select clocks, disable sleep */
176 ao_mpu6000_reg_write(MPU6000_PWR_MGMT_1,
177 (0 << MPU6000_PWR_MGMT_1_DEVICE_RESET) |
178 (0 << MPU6000_PWR_MGMT_1_SLEEP) |
179 (0 << MPU6000_PWR_MGMT_1_CYCLE) |
180 (0 << MPU6000_PWR_MGMT_1_TEMP_DIS) |
181 (MPU6000_PWR_MGMT_1_CLKSEL_PLL_X_AXIS << MPU6000_PWR_MGMT_1_CLKSEL));
183 /* Set sample rate divider to sample at full speed
184 ao_mpu6000_reg_write(MPU6000_SMPRT_DIV, 0);
186 /* Disable filtering */
187 ao_mpu6000_reg_write(MPU6000_CONFIG,
188 (MPU6000_CONFIG_EXT_SYNC_SET_DISABLED << MPU6000_CONFIG_EXT_SYNC_SET) |
189 (MPU6000_CONFIG_DLPF_CFG_260_256 << MPU6000_CONFIG_DLPF_CFG));
191 /* Configure accelerometer to +/-16G in self-test mode */
192 ao_mpu6000_reg_write(MPU6000_ACCEL_CONFIG,
193 (1 << MPU600_ACCEL_CONFIG_XA_ST) |
194 (1 << MPU600_ACCEL_CONFIG_YA_ST) |
195 (1 << MPU600_ACCEL_CONFIG_ZA_ST) |
196 (MPU600_ACCEL_CONFIG_AFS_SEL_16G << MPU600_ACCEL_CONFIG_AFS_SEL));
198 /* Configure gyro to +/- 2000°/s in self-test mode */
199 ao_mpu6000_reg_write(MPU6000_GYRO_CONFIG,
200 (1 << MPU600_GYRO_CONFIG_XG_ST) |
201 (1 << MPU600_GYRO_CONFIG_YG_ST) |
202 (1 << MPU600_GYRO_CONFIG_ZG_ST) |
203 (MPU600_GYRO_CONFIG_FS_SEL_2000 << MPU600_GYRO_CONFIG_FS_SEL));
205 ao_delay(AO_MS_TO_TICKS(200));
206 ao_mpu6000_sample(&test_mode);
208 /* Configure accelerometer to +/-16G */
209 ao_mpu6000_reg_write(MPU6000_ACCEL_CONFIG,
210 (0 << MPU600_ACCEL_CONFIG_XA_ST) |
211 (0 << MPU600_ACCEL_CONFIG_YA_ST) |
212 (0 << MPU600_ACCEL_CONFIG_ZA_ST) |
213 (MPU600_ACCEL_CONFIG_AFS_SEL_16G << MPU600_ACCEL_CONFIG_AFS_SEL));
215 /* Configure gyro to +/- 2000°/s */
216 ao_mpu6000_reg_write(MPU6000_GYRO_CONFIG,
217 (0 << MPU600_GYRO_CONFIG_XG_ST) |
218 (0 << MPU600_GYRO_CONFIG_YG_ST) |
219 (0 << MPU600_GYRO_CONFIG_ZG_ST) |
220 (MPU600_GYRO_CONFIG_FS_SEL_2000 << MPU600_GYRO_CONFIG_FS_SEL));
222 ao_delay(AO_MS_TO_TICKS(10));
223 ao_mpu6000_sample(&normal_mode);
225 ao_mpu6000_accel_check(normal_mode.accel_x, test_mode.accel_x, "x");
226 ao_mpu6000_accel_check(normal_mode.accel_y, test_mode.accel_y, "y");
227 ao_mpu6000_accel_check(normal_mode.accel_z, test_mode.accel_z, "z");
229 ao_mpu6000_gyro_check(normal_mode.gyro_x, test_mode.gyro_x, "x");
230 ao_mpu6000_gyro_check(normal_mode.gyro_y, test_mode.gyro_y, "y");
231 ao_mpu6000_gyro_check(normal_mode.gyro_z, test_mode.gyro_z, "z");
233 /* Filter to about 100Hz, which also sets the gyro rate to 1000Hz */
234 ao_mpu6000_reg_write(MPU6000_CONFIG,
235 (MPU6000_CONFIG_EXT_SYNC_SET_DISABLED << MPU6000_CONFIG_EXT_SYNC_SET) |
236 (MPU6000_CONFIG_DLPF_CFG_94_98 << MPU6000_CONFIG_DLPF_CFG));
238 /* Set sample rate divider to sample at 200Hz (v = gyro/rate - 1) */
239 ao_mpu6000_reg_write(MPU6000_SMPRT_DIV,
242 ao_delay(AO_MS_TO_TICKS(100));
243 ao_mpu6000_configured = 1;
248 ao_mpu6000_show(void)
250 struct ao_mpu6000_sample sample;
253 ao_mpu6000_sample(&sample);
254 printf ("Accel: %7d %7d %7d Gyro: %7d %7d %7d\n",
255 ao_mpu6000_accel(sample.accel_x),
256 ao_mpu6000_accel(sample.accel_y),
257 ao_mpu6000_accel(sample.accel_z),
258 ao_mpu6000_gyro(sample.gyro_x),
259 ao_mpu6000_gyro(sample.gyro_y),
260 ao_mpu6000_gyro(sample.gyro_z));
263 static const struct ao_cmds ao_mpu6000_cmds[] = {
264 { ao_mpu6000_show, "I\0Show MPU6000 status" },
269 ao_mpu6000_init(void)
271 ao_mpu6000_configured = 0;
273 ao_cmd_register(&ao_mpu6000_cmds[0]);