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.
22 #define AO_DATA_ADC (1 << 0)
28 #include <ao_ms5607.h>
29 #define AO_DATA_MS5607 (1 << 1)
31 #define AO_DATA_MS5607 0
35 #include <ao_mpu6000.h>
36 #define AO_DATA_MPU6000 (1 << 2)
38 #define AO_DATA_MPU6000 0
42 #include <ao_hmc5883.h>
43 #define AO_DATA_HMC5883 (1 << 3)
45 #define AO_DATA_HMC5883 0
49 #include <ao_mma655x.h>
50 #define AO_DATA_MMA655X (1 << 4)
52 #define AO_DATA_MMA655X 0
57 #define AO_DATA_ALL (AO_DATA_ADC|AO_DATA_MS5607|AO_DATA_MPU6000|AO_DATA_HMC5883|AO_DATA_MMA655X)
65 struct ao_ms5607_sample ms5607_raw;
66 struct ao_ms5607_value ms5607_cooked;
69 struct ao_mpu6000_sample mpu6000;
75 struct ao_hmc5883_sample hmc5883;
82 #define ao_data_ring_next(n) (((n) + 1) & (AO_DATA_RING - 1))
83 #define ao_data_ring_prev(n) (((n) - 1) & (AO_DATA_RING - 1))
85 extern volatile __xdata struct ao_data ao_data_ring[AO_DATA_RING];
86 extern volatile __data uint8_t ao_data_head;
87 extern volatile __data uint8_t ao_data_present;
88 extern volatile __data uint8_t ao_data_count;
91 * Mark a section of data as ready, check for data complete
93 #define AO_DATA_PRESENT(bit) do { \
94 if ((ao_data_present |= (bit)) == AO_DATA_ALL) { \
95 ao_data_ring[ao_data_head].tick = ao_tick_count; \
96 ao_data_head = ao_data_ring_next(ao_data_head); \
97 ao_data_present = 0; \
98 ao_wakeup((void *) &ao_data_head); \
103 * Wait until it is time to write a sensor sample; this is
104 * signaled by the timer tick
106 #define AO_DATA_WAIT() do { \
107 ao_sleep((void *) &ao_data_count); \
110 #endif /* AO_DATA_RING */
112 #if !HAS_BARO && HAS_MS5607
114 /* Either an MS5607 or an MS5611 hooked to a SPI port
119 typedef int32_t pres_t;
122 #define AO_ALT_TYPE int32_t
125 typedef AO_ALT_TYPE alt_t;
127 #define ao_data_pres_cook(packet) ao_ms5607_convert(&packet->ms5607_raw, &packet->ms5607_cooked)
129 #define ao_data_pres(packet) ((packet)->ms5607_cooked.pres)
130 #define ao_data_temp(packet) ((packet)->ms5607_cooked.temp)
132 #define pres_to_altitude(p) ao_pa_to_altitude(p)
136 #if !HAS_BARO && HAS_ADC
140 typedef int16_t pres_t;
141 typedef int16_t alt_t;
143 #define ao_data_pres(packet) ((packet)->adc.pres)
144 #define ao_data_temp(packet) ((packet)->adc.temp)
145 #define pres_to_altitude(p) ao_pres_to_altitude(p)
146 #define ao_data_pres_cook(p)
151 typedef int16_t alt_t;
155 * Need a few macros to pull data from the sensors:
157 * ao_data_accel_sample - pull raw sensor and convert to normalized values
158 * ao_data_accel - pull normalized value (lives in the same memory)
159 * ao_data_set_accel - store normalized value back in the sensor location
160 * ao_data_accel_invert - flip rocket ends for positive acceleration
165 /* This section is for an analog accelerometer hooked to one of the ADC pins. As
166 * those are 5V parts, this also requires that the 5V supply be hooked to to anothe ADC
167 * pin so that the both can be measured to correct for changes between the 3.3V and 5V rails
170 typedef int16_t accel_t;
171 #define ao_data_accel(packet) ((packet)->adc.accel)
172 #define ao_data_set_accel(packet, a) ((packet)->adc.accel = (a))
173 #define ao_data_accel_invert(a) (0x7fff -(a))
176 * Ok, the math here is a bit tricky.
178 * ao_sample_accel: ADC output for acceleration
179 * ao_accel_ref: ADC output for the 5V reference.
180 * ao_cook_accel: Corrected acceleration value
181 * Vcc: 3.3V supply to the CC1111
182 * Vac: 5V supply to the accelerometer
183 * accel: input voltage to accelerometer ADC pin
184 * ref: input voltage to 5V reference ADC pin
187 * Measured acceleration is ratiometric to Vcc:
189 * ao_sample_accel accel
190 * ------------ = -----
193 * Measured 5v reference is also ratiometric to Vcc:
196 * ------------ = -----
200 * ao_accel_ref = 32767 * (ref / Vcc)
202 * Acceleration is measured ratiometric to the 5V supply,
203 * so what we want is:
205 * ao_cook_accel accel
206 * ------------- = -----
214 * ao_sample_accel 32767
215 * = ------------ * ------------
218 * Multiply through by 32767:
220 * ao_sample_accel * 32767
221 * ao_cook_accel = --------------------
224 * Now, the tricky part. Getting this to compile efficiently
225 * and keeping all of the values in-range.
227 * First off, we need to use a shift of 16 instead of * 32767 as SDCC
228 * does the obvious optimizations for byte-granularity shifts:
230 * ao_cook_accel = (ao_sample_accel << 16) / ao_accel_ref
232 * Next, lets check our input ranges:
234 * 0 <= ao_sample_accel <= 0x7fff (singled ended ADC conversion)
235 * 0x7000 <= ao_accel_ref <= 0x7fff (the 5V ref value is close to 0x7fff)
237 * Plugging in our input ranges, we get an output range of 0 - 0x12490,
238 * which is 17 bits. That won't work. If we take the accel ref and shift
239 * by a bit, we'll change its range:
241 * 0xe000 <= ao_accel_ref<<1 <= 0xfffe
243 * ao_cook_accel = (ao_sample_accel << 16) / (ao_accel_ref << 1)
245 * Now the output range is 0 - 0x9248, which nicely fits in 16 bits. It
246 * is, however, one bit too large for our signed computations. So, we
247 * take the result and shift that by a bit:
249 * ao_cook_accel = ((ao_sample_accel << 16) / (ao_accel_ref << 1)) >> 1
251 * This finally creates an output range of 0 - 0x4924. As the ADC only
252 * provides 11 bits of data, we haven't actually lost any precision,
253 * just dropped a bit of noise off the low end.
258 #define ao_data_accel_cook(packet) \
259 ((uint16_t) ((((uint32_t) (packet)->adc.accel << 16) / ((packet)->adc.accel_ref << 1))) >> 1)
263 #define ao_data_accel_cook(packet) ((packet)->adc.accel)
265 #endif /* HAS_ACCEL_REF */
267 #endif /* HAS_ACCEL */
269 #if !HAS_ACCEL && HAS_MMA655X
273 typedef int16_t accel_t;
275 /* MMA655X is hooked up so that positive values represent negative acceleration */
277 #define ao_data_accel(packet) ((packet)->mma655x)
278 #define ao_data_accel_cook(packet) ((packet)->mma655x)
279 #define ao_data_set_accel(packet, accel) ((packet)->mma655x = (accel))
280 #define ao_data_accel_invert(accel) (4095 - (accel))
284 #if !HAS_ACCEL && HAS_MPU6000
288 typedef int16_t accel_t;
290 /* MPU6000 is hooked up so that positive y is positive acceleration */
291 #define ao_data_accel(packet) ((packet)->z_accel)
292 #define ao_data_accel_cook(packet) (-(packet)->mpu6000.accel_y)
293 #define ao_data_set_accel(packet, accel) ((packet)->z_accel = (accel))
294 #define ao_data_accel_invert(a) (-(a))
298 #endif /* _AO_DATA_H_ */