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
55 #define AO_DATA_ALL (AO_DATA_ADC|AO_DATA_MS5607|AO_DATA_MPU6000|AO_DATA_HMC5883|AO_DATA_MMA655X)
63 struct ao_ms5607_sample ms5607_raw;
64 struct ao_ms5607_value ms5607_cooked;
67 struct ao_mpu6000_sample mpu6000;
70 struct ao_hmc5883_sample hmc5883;
77 #define ao_data_ring_next(n) (((n) + 1) & (AO_DATA_RING - 1))
78 #define ao_data_ring_prev(n) (((n) - 1) & (AO_DATA_RING - 1))
80 extern volatile __xdata struct ao_data ao_data_ring[AO_DATA_RING];
81 extern volatile __data uint8_t ao_data_head;
82 extern volatile __data uint8_t ao_data_present;
83 extern volatile __data uint8_t ao_data_count;
86 * Mark a section of data as ready, check for data complete
88 #define AO_DATA_PRESENT(bit) (ao_data_present |= (bit))
91 * Wait until it is time to write a sensor sample; this is
92 * signaled by the timer tick
94 #define AO_DATA_WAIT() do { \
95 ao_sleep((void *) &ao_data_count); \
98 #if !HAS_BARO && HAS_MS5607
100 /* Either an MS5607 or an MS5611 hooked to a SPI port
105 typedef int32_t pres_t;
106 typedef int32_t alt_t;
108 #define ao_data_pres_cook(packet) ao_ms5607_convert(&packet->ms5607_raw, &packet->ms5607_cooked)
110 #define ao_data_pres(packet) ((packet)->ms5607_cooked.pres)
111 #define ao_data_temp(packet) ((packet)->ms5607_cooked.temp)
113 #define pres_to_altitude(p) ao_pa_to_altitude(p)
117 #if !HAS_BARO && HAS_ADC
121 typedef int16_t pres_t;
122 typedef int16_t alt_t;
124 #define ao_data_pres(packet) ((packet)->adc.pres)
125 #define ao_data_temp(packet) ((packet)->adc.temp)
126 #define pres_to_altitude(p) ao_pres_to_altitude(p)
127 #define ao_data_pres_cook(p)
132 * Need a few macros to pull data from the sensors:
134 * ao_data_accel_sample - pull raw sensor and convert to normalized values
135 * ao_data_accel - pull normalized value (lives in the same memory)
136 * ao_data_set_accel - store normalized value back in the sensor location
137 * ao_data_accel_invert - flip rocket ends for positive acceleration
142 /* This section is for an analog accelerometer hooked to one of the ADC pins. As
143 * those are 5V parts, this also requires that the 5V supply be hooked to to anothe ADC
144 * pin so that the both can be measured to correct for changes between the 3.3V and 5V rails
147 typedef int16_t accel_t;
148 #define ao_data_accel(packet) ((packet)->adc.accel)
149 #define ao_data_set_accel(packet, a) ((packet)->adc.accel = (a))
150 #define ao_data_accel_invert(a) (0x7fff -(a))
153 * Ok, the math here is a bit tricky.
155 * ao_sample_accel: ADC output for acceleration
156 * ao_accel_ref: ADC output for the 5V reference.
157 * ao_cook_accel: Corrected acceleration value
158 * Vcc: 3.3V supply to the CC1111
159 * Vac: 5V supply to the accelerometer
160 * accel: input voltage to accelerometer ADC pin
161 * ref: input voltage to 5V reference ADC pin
164 * Measured acceleration is ratiometric to Vcc:
166 * ao_sample_accel accel
167 * ------------ = -----
170 * Measured 5v reference is also ratiometric to Vcc:
173 * ------------ = -----
177 * ao_accel_ref = 32767 * (ref / Vcc)
179 * Acceleration is measured ratiometric to the 5V supply,
180 * so what we want is:
182 * ao_cook_accel accel
183 * ------------- = -----
191 * ao_sample_accel 32767
192 * = ------------ * ------------
195 * Multiply through by 32767:
197 * ao_sample_accel * 32767
198 * ao_cook_accel = --------------------
201 * Now, the tricky part. Getting this to compile efficiently
202 * and keeping all of the values in-range.
204 * First off, we need to use a shift of 16 instead of * 32767 as SDCC
205 * does the obvious optimizations for byte-granularity shifts:
207 * ao_cook_accel = (ao_sample_accel << 16) / ao_accel_ref
209 * Next, lets check our input ranges:
211 * 0 <= ao_sample_accel <= 0x7fff (singled ended ADC conversion)
212 * 0x7000 <= ao_accel_ref <= 0x7fff (the 5V ref value is close to 0x7fff)
214 * Plugging in our input ranges, we get an output range of 0 - 0x12490,
215 * which is 17 bits. That won't work. If we take the accel ref and shift
216 * by a bit, we'll change its range:
218 * 0xe000 <= ao_accel_ref<<1 <= 0xfffe
220 * ao_cook_accel = (ao_sample_accel << 16) / (ao_accel_ref << 1)
222 * Now the output range is 0 - 0x9248, which nicely fits in 16 bits. It
223 * is, however, one bit too large for our signed computations. So, we
224 * take the result and shift that by a bit:
226 * ao_cook_accel = ((ao_sample_accel << 16) / (ao_accel_ref << 1)) >> 1
228 * This finally creates an output range of 0 - 0x4924. As the ADC only
229 * provides 11 bits of data, we haven't actually lost any precision,
230 * just dropped a bit of noise off the low end.
235 #define ao_data_accel_cook(packet) \
236 ((uint16_t) ((((uint32_t) (packet)->adc.accel << 16) / ((packet)->adc.accel_ref << 1))) >> 1)
240 #define ao_data_accel_cook(packet) ((packet)->adc.accel)
242 #endif /* HAS_ACCEL_REF */
244 #endif /* HAS_ACCEL */
246 #if !HAS_ACCEL && HAS_MMA655X
250 typedef int16_t accel_t;
252 /* MMA655X is hooked up so that positive values represent negative acceleration */
254 #define ao_data_accel(packet) ((packet)->mma655x)
255 #define ao_data_accel_cook(packet) ((packet)->mma655x)
256 #define ao_data_set_accel(packet, accel) ((packet)->mma655x = (accel))
257 #define ao_data_accel_invert(accel) (4095 - (accel))
261 #if !HAS_ACCEL && HAS_MPU6000
265 typedef int16_t accel_t;
267 /* MPU6000 is hooked up so that positive y is positive acceleration */
268 #define ao_data_accel(packet) ((packet)->mpu6000.accel_y)
269 #define ao_data_accel_cook(packet) (-(packet)->mpu6000.accel_y)
270 #define ao_data_set_accel(packet, accel) ((packet)->mpu6000.accel_y = (accel))
271 #define ao_data_accel_invert(a) (-(a))
275 #endif /* _AO_DATA_H_ */