example_processing_static_presence.c
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1 // Copyright (c) Acconeer AB, 2023
2 // All rights reserved
3 // This file is subject to the terms and conditions defined in the file
4 // 'LICENSES/license_acconeer.txt', (BSD 3-Clause License) which is part
5 // of this source code package.
6
7
8 /** \example example_processing_static_presence.c
9 * @brief example_processing_static_presence.c
10 * Example program that shows how the spread of the phase values can be used
11 * to determine if there is a static object in front of the radar.
12 *
13 * In this example we use the the ratio of the coherent average to the noncoherent
14 * average to calculate the spread and determine if the phase values are aligned or
15 * not. It is also possible to measure the spread in other way, for example by
16 * calculating the standard deviation of the phase values.
17 *
18 * Note that this example is mainly intended for detecting the precense of static
19 * objects in front of the radar sensor, while Acconeer's presence detector detects
20 * objects that moves or vibrates sligtly, ignoring static objects.
21 */
22
23
24 #include <stdbool.h>
25 #include <stdint.h>
26 #include <stdio.h>
27
28 #include "acc_config.h"
29 #include "acc_hal_definitions_a121.h"
30 #include "acc_hal_integration_a121.h"
31 #include "acc_integration_log.h"
32 #include "acc_rss_a121.h"
33 #include "acc_version.h"
34
35
36 #include "acc_processing_helpers.h"
37
38
39 #define SENSOR_ID (1U)
40
41 #define SWEEPS_PER_FRAME 16
42 #define PHASE_SPREAD_TRESHOLD (0.01f)
43
44
45 static void update_configuration(acc_config_t *config);
46
47
48 int acconeer_main(int argc, char *argv[]);
49
50
51 int acconeer_main(int argc, char *argv[])
52 {
53 (void)argc;
54 (void)argv;
55
56 acc_control_helper_t control_helper_state = {0};
57
58 printf("Acconeer software version %s\n", acc_version_get());
59
60 const acc_hal_a121_t *hal = acc_hal_rss_integration_get_implementation();
61
62 if (!acc_rss_hal_register(hal))
63 {
64 return EXIT_FAILURE;
65 }
66
67 bool res = acc_control_helper_create(&control_helper_state, SENSOR_ID);
68
69 if (!res)
70 {
71 printf("acc_control_helper_create() failed\n");
72 return EXIT_FAILURE;
73 }
74
75 update_configuration(control_helper_state.config);
76
77 res = acc_control_helper_activate(&control_helper_state);
78
79 if (!res)
80 {
81 printf("acc_control_helper_activate() failed\n");
82 acc_control_helper_destroy(&control_helper_state);
83 return EXIT_FAILURE;
84 }
85
86 uint32_t sweep_data_length = control_helper_state.proc_meta.sweep_data_length;
87 uint32_t point_vector_length = SWEEPS_PER_FRAME;
88
89 acc_vector_float_t *phase_spread = acc_vector_float_alloc(sweep_data_length);
90 acc_vector_iq_t *point_vector = acc_vector_iq_alloc(point_vector_length);
91
92 bool mem_ok = (phase_spread != NULL) && (point_vector != NULL);
93 if (!mem_ok)
94 {
95 printf("Memory allocation for vectors failed\n");
96 goto clean_up;
97 }
98
99 uint32_t iterations = 5U;
100 for (uint32_t i = 0U; i < iterations; i++)
101 {
102 res = acc_control_helper_get_next(&control_helper_state);
103 if (!res)
104 {
105 printf("acc_control_helper_get_next() failed\n");
106 break;
107 }
108
109 for (uint32_t p = 0U; p < sweep_data_length; p++)
110 {
111 acc_get_iq_point_vector(&control_helper_state, p, point_vector);
112
113 // The ratio of the coherent average to the noncoherent average is used to determine
114 // the amount of phase spread. When the phases of the values in the array are similar,
115 // the coherent average approaches the noncoherent average. However, if the phase
116 // values are uniformly distributed around the unit circle and have the same
117 // amplitudes, they cancel out, resulting in a coherent average of 0, while the
118 // noncoherent average is still the average of the amplitudes.
119
120 // As a result, when there is an object in front of the radar and the spread is low,
121 // the ratio is close to 1. When there is no object in front of the radar and the
122 // phase values are random, the ratio is closer to 0.
123
124 // We set the phase spread to be 1 minus the ratio.
125
126 float coherent_mean = acc_vector_iq_coherent_mean_amplitude(point_vector);
127 float noncoherent_mean = acc_vector_iq_noncoherent_mean_amplitude(point_vector);
128
129 phase_spread->data[p] = 1 - coherent_mean / noncoherent_mean;
130 }
131
132 // Print a line with a dot or star for each distance point. A star ('*') means that there
133 // is an object in front of the radar at the distance point and a dot ('.') means that
134 // there is no object in front of the radar.
135 for (uint32_t p = 0U; p < sweep_data_length; p++)
136 {
137 printf("%c", phase_spread->data[p] > PHASE_SPREAD_TRESHOLD ? '.' : '*');
138 }
139
140 printf("\n");
141 }
142
143 clean_up:
144 acc_vector_iq_free(point_vector);
145 acc_vector_float_free(phase_spread);
146 acc_control_helper_destroy(&control_helper_state);
147
148 if (res && mem_ok)
149 {
150 printf("Application finished OK\n");
151 return EXIT_SUCCESS;
152 }
153 else
154 {
155 return EXIT_FAILURE;
156 }
157 }
158
159
160 static void update_configuration(acc_config_t *config)
161 {
162 int32_t start_point = 100; // start at 250 mm
163 uint16_t step_length = 24; // 24*2.5 mm = 60 mm
164 uint16_t num_points = 20; // range length 20*24*2.5 mm = 1200 mm
165
166 acc_config_start_point_set(config, start_point);
167 acc_config_num_points_set(config, num_points);
168 acc_config_step_length_set(config, step_length);
169 acc_config_profile_set(config, ACC_CONFIG_PROFILE_3);
170 acc_config_hwaas_set(config, 30);
171 // The processing in this example assumes that sweeps_per_frame > 1
172 acc_config_sweeps_per_frame_set(config, SWEEPS_PER_FRAME);
173 acc_config_prf_set(config, ACC_CONFIG_PRF_13_0_MHZ);
174 }
acc_config_start_point_set
void acc_config_start_point_set(acc_config_t *config, int32_t start_point)
Set the starting point of the sweep.
SENSOR_ID
#define SENSOR_ID
Definition: example_processing_static_presence.c:39
acc_control_helper_create
bool acc_control_helper_create(acc_control_helper_t *radar, acc_sensor_id_t sensor_id)
Create a helper instance.
Definition: acc_control_helper.c:41
acc_rss_a121.h
acc_vector_iq_coherent_mean_amplitude
float acc_vector_iq_coherent_mean_amplitude(const acc_vector_iq_t *vector_a)
Coherent mean amplitude of IQ vector.
Definition: acc_processing_helpers.c:316
acc_get_iq_point_vector
void acc_get_iq_point_vector(const acc_control_helper_t *control_helper_state, uint32_t point, acc_vector_iq_t *vector_out)
Extract an IQ vector with sweep data for a specific point from a newly captured IQ frame with multipl...
Definition: acc_processing_helpers.c:152
acc_vector_float_free
void acc_vector_float_free(acc_vector_float_t *vector)
Free storage of data elements in a float vector.
Definition: acc_processing_helpers.c:85
acconeer_main
int acconeer_main(int argc, char *argv[])
Assembly test example.
Definition: example_processing_static_presence.c:51
acc_vector_iq_free
void acc_vector_iq_free(acc_vector_iq_t *vector)
Free storage of data elements in an IQ vector.
Definition: acc_processing_helpers.c:73
acc_control_helper_t::config
acc_config_t * config
Definition: acc_control_helper.h:25
PHASE_SPREAD_TRESHOLD
#define PHASE_SPREAD_TRESHOLD
Definition: example_processing_static_presence.c:42
acc_version.h
acc_config_profile_set
void acc_config_profile_set(acc_config_t *config, acc_config_profile_t profile)
Set a profile.
acc_config_sweeps_per_frame_set
void acc_config_sweeps_per_frame_set(acc_config_t *config, uint16_t sweeps)
Set sweeps per frame.
acc_vector_float_t::data
float * data
Definition: acc_processing_helpers.h:36
acc_control_helper_destroy
void acc_control_helper_destroy(acc_control_helper_t *radar)
Destroy a helper instance.
Definition: acc_control_helper.c:50
acc_hal_rss_integration_get_implementation
const acc_hal_a121_t * acc_hal_rss_integration_get_implementation(void)
Get hal implementation reference.
Definition: acc_hal_integration_stm32cube_xm.c:166
acc_vector_iq_t
Definition: acc_processing_helpers.h:27
acc_hal_a121_t
Definition: acc_hal_definitions_a121.h:82
acc_control_helper_t::proc_meta
acc_processing_metadata_t proc_meta
Definition: acc_control_helper.h:32
acc_rss_hal_register
bool acc_rss_hal_register(const acc_hal_a121_t *hal)
Register an integration.
ACC_CONFIG_PRF_13_0_MHZ
@ ACC_CONFIG_PRF_13_0_MHZ
Definition: acc_definitions_a121.h:110
acc_config_hwaas_set
void acc_config_hwaas_set(acc_config_t *config, uint16_t hwaas)
Set the hardware accelerated average samples (HWAAS)
acc_processing_metadata_t::sweep_data_length
uint16_t sweep_data_length
Definition: acc_processing.h:41
update_configuration
static void update_configuration(acc_config_t *config)
Definition: example_processing_static_presence.c:160
acc_hal_integration_a121.h
acc_version_get
const char * acc_version_get(void)
Get the version of the Acconeer software.
acc_config_t
struct acc_config acc_config_t
Definition: acc_config.h:26
printf
#define printf
Definition: printf.h:60
acc_config_step_length_set
void acc_config_step_length_set(acc_config_t *config, uint16_t step_length)
Set the step length in a sweep.
acc_config_num_points_set
void acc_config_num_points_set(acc_config_t *config, uint16_t num_points)
Set the number of data points to measure.
acc_hal_definitions_a121.h
acc_processing_helpers.h
acc_vector_float_t
Definition: acc_processing_helpers.h:33
acc_integration_log.h
acc_vector_iq_alloc
acc_vector_iq_t * acc_vector_iq_alloc(uint32_t data_length)
Allocate storage for an IQ vector.
Definition: acc_processing_helpers.c:27
acc_vector_float_alloc
acc_vector_float_t * acc_vector_float_alloc(uint32_t data_length)
Allocate storage for a float vector.
Definition: acc_processing_helpers.c:50
SWEEPS_PER_FRAME
#define SWEEPS_PER_FRAME
Definition: example_processing_static_presence.c:41
acc_control_helper_t
Definition: acc_control_helper.h:23
acc_vector_iq_noncoherent_mean_amplitude
float acc_vector_iq_noncoherent_mean_amplitude(const acc_vector_iq_t *vector_a)
Non-coherent mean amplitude of IQ vector.
Definition: acc_processing_helpers.c:331
acc_control_helper_activate
bool acc_control_helper_activate(acc_control_helper_t *radar)
Activate the sensor.
Definition: acc_control_helper.c:81
acc_config_prf_set
void acc_config_prf_set(acc_config_t *config, acc_config_prf_t prf)
Set Pulse Repetition Frequency.
acc_config.h
ACC_CONFIG_PROFILE_3
@ ACC_CONFIG_PROFILE_3
Definition: acc_definitions_a121.h:44
acc_control_helper_get_next
bool acc_control_helper_get_next(acc_control_helper_t *radar)
Perform a radar measurement and wait for the result.
Definition: acc_control_helper.c:157