Previously, this compiler flag was not being applied
regardless of CONFIG_SPIRAM_CACHE_WORKAROUND setting.
Explanation: add_compile_options() only applies to
source files added after the function is run, or in
subdirectories added after the function is run. In
this case, no new source files were being added after
this function was run.
Due to a hardware limitation in ESP32, the first four bytes of some
CSI data is invalid, not the last four bytes.
Correct a mistake of CSI sub-carrier index in documentation.
Added a new structure esp_app_desc_t. It has info about firmware:
version, secure_version, project_name, time/date build and IDF version.
Added the ability to add a custom structure with a description of the firmware.
The esp_app_desc_t is located in fixed place in start of ROM secotor. It is located after structures esp_image_header_t and esp_image_segment_header_t.
app_version is filed from PROJECT_VER variable (if set in custom make file) or PROJECT_PATH/version.txt or git repo (git describe).
Add API to get app_desc from partition.
1. add network channel switch function.
- users can obtain the new channel through the event MESH_EVENT_CHANNEL_SWITCH.
- the entire network will be moved to the same channel as the router without user intervention.
- if no router is in the network, users can call esp_mesh_switch_channel() on the root side to
move the entire network to their desired channel.
2. support not configuring the network channel.
3. support not configuring the router BSSID even if the router is hidden.
4. add allow_channel_switch to mesh configuration.
- if the channel is not specified, this value will be ignored.
- if the channel is specified and this value is set, when "fail" (mesh_attempts_t) times of parent selection
or look for networks are reached, device will change to perform a full channel scan for networks that could join.
- if the channel is specified and this value is set to 0, when a root is not elected, channel switch is not allowed.
but when a root appears, the root performs a full channel scan during the process of connecting to the router,
so even allow_channel_switch is set to 0, the root may still switch channel and eventually the entire network
changes channel.
5. add allow_router_switch to mesh router configuration.
- if the BSSID of router is not specified, this value will be ignored.
- if the BSSID of router is specified and this value is set, when the router of this specified BSSID fails to be found
after "fail" (mesh_attempts_t) times, the entire network is allowed to switch to another router with the same SSID.
6. modify the root to perform a full channel scan when esp_wifi_connect().
7. support handling beacon without DS Paramter Set.
