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Merge branch 'feature/scan_optimize' into 'master'

wifi: scan optimize

See merge request !1334
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jack0c committed Oct 10, 2017
2 parents 10c1dfe + d515494 commit 904d6c8f2b01de52597b9e16dad19c78ade9e586
@@ -162,6 +162,11 @@ typedef enum {
WIFI_CONNECT_AP_BY_SECURITY, /**< Sort match AP in scan list by security mode */
}wifi_sort_method_t;

typedef struct {
int8_t rssi; /**< The minimum rssi to accept in the fast scan mode */
wifi_auth_mode_t authmode; /**< The weakest authmode to accept in the fast scan mode */
}wifi_fast_scan_threshold_t;

typedef enum {
WIFI_PS_NONE, /**< No power save */
WIFI_PS_MODEM, /**< Modem power save */
@@ -196,6 +201,7 @@ typedef struct {
uint8_t bssid[6]; /**< MAC address of target AP*/
uint8_t channel; /**< channel of target AP. Set to 1~13 to scan starting from the specified channel before connecting to AP. If the channel of AP is unknown, set it to 0.*/
wifi_sort_method_t sort_method; /**< sort the connect AP in the list by rssi or security mode */
wifi_fast_scan_threshold_t threshold; /**< When scan_method is set to WIFI_FAST_SCAN, only APs which have an auth mode that is more secure than the selected auth mode and a signal stronger than the minimum RSSI will be used. */
} wifi_sta_config_t;

typedef union {
@@ -20,6 +20,7 @@ ESP32 Wi-Fi Feature List
- Up to 20 MBit/sec TCP throughput and 30 MBit/sec UDP throughput over the air
- Supports Sniffer
- Support set fast_crypto algorithm and normal algorithm switch which used in wifi connect
- Support both fast scan and all channel scan feature

How To Write a Wi-Fi Application
----------------------------------
@@ -0,0 +1,9 @@
#
# This is a project Makefile. It is assumed the directory this Makefile resides in is a
# project subdirectory.
#

PROJECT_NAME := scan

include $(IDF_PATH)/make/project.mk

@@ -0,0 +1,11 @@
# Wifi SCAN Example

This example shows how to use scan of ESP32.

We have two way to scan, fast scan and all channel scan:

* fast scan: in this mode, scan will finish after find match AP even didn't scan all the channel, you can set thresholds for signal and authmode, it will ignore the AP which below the thresholds.

* all channel scan : scan will end after checked all the channel, it will store four of the whole matched AP, you can set the sort method base on rssi or authmode, after scan, it will choose the best one

and try to connect. Because it need malloc dynamic memory to store match AP, and most of cases is to connect to better signal AP, so it needn't record all the AP matched. The number of matches is limited to 4 in order to limit dynamic memory usage. Four matches allows APs with the same SSID name and all possible auth modes - Open, WEP, WPA and WPA2.
@@ -0,0 +1,68 @@
menu "Example Configuration"

config WIFI_SSID
string "WiFi SSID"
default "myssid"
help
SSID (network name) for the example to connect to.

config WIFI_PASSWORD
string "WiFi Password"
default "mypassword"
help
WiFi password (WPA or WPA2) for the example to use.

choice SCAN_METHOD
prompt "scan method"
default WIFI_FAST_SCAN
help
scan method for the esp32 to use

config WIFI_FAST_SCAN
bool "fast"
config WIFI_ALL_CHANNEL_SCAN
bool "all"
endchoice

choice SORT_METHOD
prompt "sort method"
default WIFI_CONNECT_AP_BY_SIGNAL
help
sort method for the esp32 to use

config WIFI_CONNECT_AP_BY_SIGNAL
bool "rssi"
config WIFI_CONNECT_AP_BY_SECURITY
bool "authmode"
endchoice

config FAST_SCAN_THRESHOLD
bool "fast scan threshold"
default y
help
wifi fast scan threshold

config FAST_SCAN_MINIMUM_SIGNAL
int "fast scan minimum rssi"
depends on FAST_SCAN_THRESHOLD
range -127 0
default -127
help
rssi is use to measure the signal

choice FAST_SCAN_WEAKEST_AUTHMODE
prompt "fast scan weakest authmode"
depends on FAST_SCAN_THRESHOLD
default EXAMPLE_OPEN

config EXAMPLE_OPEN
bool "open"
config EXAMPLE_WEP
bool "wep"
config EXAMPLE_WPA
bool "wpa"
config EXAMPLE_WPA2
bool "wpa2"
endchoice

endmenu
@@ -0,0 +1,7 @@
#
# "main" pseudo-component makefile.
#
# (Uses default behaviour of compiling all source files in directory, adding 'include' to include path.)



@@ -0,0 +1,122 @@
/* Scan Example
This example code is in the Public Domain (or CC0 licensed, at your option.)
Unless required by applicable law or agreed to in writing, this
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied.
*/

/*
this example shows how to use all channel scan or fast scan to connect
In the fast scan mode, scan will end after find matched AP, in this mode, you
can set the threshold of auth mode and signal, the filter will ignore the AP
whose auth mode and rssi below the threshold.
In the all channel scan, scan will end after scan all the channel, and will
the best AP to connect, you can sort by signal or auth mode, auth mode is follow
the rule WPA2>WPA>WEP.
*/
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "esp_wifi.h"
#include "esp_log.h"
#include "esp_event_loop.h"
#include "nvs_flash.h"

/*set the ssid and password via "make menuconfig"*/
#define DEFAULT_SSID CONFIG_WIFI_SSID
#define DEFAULT_PWD CONFIG_WIFI_PASSWORD

#if CONFIG_WIFI_ALL_CHANNEL_SCAN
#define DEFAULT_SCAN_METHOD WIFI_ALL_CHANNEL_SCAN
#elif CONFIG_WIFI_FAST_SCAN
#define DEFAULT_SCAN_METHOD WIFI_FAST_SCAN
#else
#define DEFAULT_SCAN_METHOD WIFI_FAST_SCAN
#endif /*CONFIG_SCAN_METHOD*/

#if CONFIG_WIFI_CONNECT_AP_BY_SIGNAL
#define DEFAULT_SORT_METHOD WIFI_CONNECT_AP_BY_SIGNAL
#elif CONFIG_WIFI_CONNECT_AP_BY_SECURITY
#define DEFAULT_SORT_METHOD WIFI_CONNECT_AP_BY_SECURITY
#else
#define DEFAULT_SORT_METHOD WIFI_CONNECT_AP_BY_SIGNAL
#endif /*CONFIG_SORT_METHOD*/

#if CONFIG_FAST_SCAN_THRESHOLD
#define DEFAULT_RSSI CONFIG_FAST_SCAN_MINIMUM_SIGNAL
#if CONFIG_EXAMPLE_OPEN
#define DEFAULT_AUTHMODE WIFI_AUTH_OPEN
#elif CONFIG_EXAMPLE_WEP
#define DEFAULT_AUTHMODE WIFI_AUTH_WEP
#elif CONFIG_EXAMPLE_WPA
#define DEFAULT_AUTHMODE WIFI_AUTH_WPA_PSK
#elif CONFIG_EXAMPLE_WPA2
#define DEFAULT_AUTHMODE WIFI_AUTH_WPA2_PSK
#else
#define DEFAULT_AUTHMODE WIFI_AUTH_OPEN
#endif
#else
#define DEFAULT_RSSI -127
#define DEFAULT_AUTHMODE WIFI_AUTH_OPEN
#endif /*CONFIG_FAST_SCAN_THRESHOLD*/

static const char *TAG = "scan";

static esp_err_t event_handler(void *ctx, system_event_t *event)
{
switch(event->event_id) {
case SYSTEM_EVENT_STA_START:
ESP_LOGI(TAG, "SYSTEM_EVENT_STA_START");
ESP_ERROR_CHECK(esp_wifi_connect());
break;
case SYSTEM_EVENT_STA_GOT_IP:
ESP_LOGI(TAG, "SYSTEM_EVENT_STA_GOT_IP");
ESP_LOGI(TAG, "got ip:%s\n",
ip4addr_ntoa(&event->event_info.got_ip.ip_info.ip));
break;
case SYSTEM_EVENT_STA_DISCONNECTED:
ESP_LOGI(TAG, "SYSTEM_EVENT_STA_DISCONNECTED");
ESP_ERROR_CHECK(esp_wifi_connect());
break;
default:
break;
}
return ESP_OK;
}

/*init wifi as sta and set scan method*/
static void wifi_scan(void)
{
tcpip_adapter_init();
ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));

wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK(esp_wifi_init(&cfg));
wifi_config_t wifi_config = {
.sta = {
.ssid = DEFAULT_SSID,
.password = DEFAULT_PWD,
.scan_method = DEFAULT_SCAN_METHOD,
.sort_method = DEFAULT_SORT_METHOD,
.threshold.rssi = DEFAULT_RSSI,
.threshold.authmode = DEFAULT_AUTHMODE,
},
};
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));
ESP_ERROR_CHECK(esp_wifi_start());
}

void app_main()
{
// Initialize NVS
esp_err_t ret = nvs_flash_init();
if (ret == ESP_ERR_NVS_NO_FREE_PAGES) {
ESP_ERROR_CHECK(nvs_flash_erase());
ret = nvs_flash_init();
}
ESP_ERROR_CHECK( ret );

wifi_scan();
}

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