Chapter 4. Software framework
After the SNTP calibration for ESP8266 RTOS SDK v3.2, errors gradually increase. How to resolve such
issue?
This is because the ESP8266 uses software timer, which brings large errors itself. You can improve it
with the following solutions:
• For branch v3.2, you can resynchronize time (300 s is recommended) from the server regularly by
creating a task.
• For branch release-v3.3, the code of system timer has been refactored and is tested with low errors.
On the other hand, you can still synchronize time from the server regularly.
• The master branch has inherited the refactored code from branch release-v3.3. In addition, you
can congure the SNTP synchronization interval in menucong: Component config > LWIP
> SNTP > Request interval to update time (ms).
Does ESP8266 support loop-back for the device end?
• Yes, it does.
• Please enable the LOOPBACK option from lwIP in menucong: menuconfig > Component config
> LWIP > Enable per-interface loopback (type “Y”to enable).
• The device end sends data to the loopback address 127.0.0.1, and can read it from the address.
What is the default packet length for TCP/IP?
Please go to menuconfig > Component config > LWIP > TCP > Maximum Segment Size
(MSS) for the length.
When using UTC and GMT methods in SNTP protocol, why can’t I get the time of the target time zone？
• The “TZ = UTC-8”refers to POSIX time, in which “UTC”is the abbreviation of any time zone and the
number is the number of hours that the time zone is behind UTC.
• “UTC-8”indicates a certain time zone, “UTC”for short, which is -8 hours later than the actual UTC.
Therefore, “UTC+8”is 8 hours later than the actual UTC, and also 16 hours later than Beijing.
Is there any special rmware or SDK in ESP32 that can only provide AP/STA (TCP/IP bypass) without using
its internal TCP/IP so as to give developers more permissions?
The software solution ESP-Dongle can t your requirements. Please contact Business Team to sign NDA
and then get related solutions.
Espressif Systems 93
Submit Document Feedback
Release master
To Next Page
Loading...
Need help?
General