Espressif ESP32-S2 User Manual

Chapter 2. API Reference
CONFIG_LWIP_SNTP_UPDATE_DELAY
Request interval to update time (ms)
Found in: Component config > LWIP > SNTP
This option allows you to set the time update period via SNTP. Default is 1 hour. Must not be below 15
seconds by specification. (SNTPv4 RFC 4330 enforces a minimum update time of 15 seconds).
Range:
• from 15000 to 4294967295
Default value:
• 3600000
CONFIG_LWIP_ESP_LWIP_ASSERT
Enable LWIP ASSERT checks
Found in: Component config > LWIP
Enable this option keeps LWIP assertion checks enabled. It is recommended to keep this option enabled.
If asserts are disabled for the entire project, they are also disabled for LWIP and this option is ignored.
Default value:
• Yes (enabled) if COMPILER_OPTIMIZATION_ASSERTIONS_DISABLE
Hooks Contains:
• CONFIG_LWIP_HOOK_ND6_GET_GW
• CONFIG_LWIP_HOOK_IP6_ROUTE
• CONFIG_LWIP_HOOK_NETCONN_EXTERNAL_RESOLVE
• CONFIG_LWIP_HOOK_TCP_ISN
CONFIG_LWIP_HOOK_TCP_ISN
TCP ISN Hook
Found in: Component config > LWIP > Hooks
Enables to define a TCP ISN hook to randomize initial sequence number in TCP connection. The default
TCP ISN algorithm used in IDF (standardized in RFC 6528) produces ISN by combining an MD5 of
the new TCP id and a stable secret with the current time. This is because the lwIP implementation
(tcp_next_iss) is not very strong, as it does not take into consideration any platform specific entropy
source.
Set to LWIP_HOOK_TCP_ISN_CUSTOM to provide custom implementation. Set to
LWIP_HOOK_TCP_ISN_NONE to use lwIP implementation.
Available options:
• No hook declared (LWIP_HOOK_TCP_ISN_NONE)
• Default implementation (LWIP_HOOK_TCP_ISN_DEFAULT)
• Custom implementation (LWIP_HOOK_TCP_ISN_CUSTOM)
CONFIG_LWIP_HOOK_IP6_ROUTE
IPv6 route Hook
Found in: Component config > LWIP > Hooks
Enables custom IPv6 route hook. Setting this to “default”provides weak implementation stub that
could be overwritten in application code. Setting this to “custom”provides hook’s declaration only
and expects the application to implement it.
Available options:
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Espressif ESP32-S2 Specifications

General

Brand	Espressif
Model	ESP32-S2
Category	Single board computers
Language	English