Low cost NTP network clock

A while ago, I saw Tantai Zining’s work. It costs 15 yuan to make a WiFi clock that is not afraid of power outages.
[Production Sharing] It costs 15 yuan to make a WiFi clock that is not afraid of power outages_bilibili_bilibili
Just thought about it I modified my NTP clock and made a low-cost version, keeping the cost at about ten yuan.
It mainly uses esp-01s, 0.56-inch clock bell-shaped 4-bit common anode digital tube, and NTP clock made by TM1637.
After finishing it, I found that the program often failed to connect to the server through Suning's network timing, and the time was not accurate every minute. Later, I modified the program with reference to the flying Akarin. If you don’t understand the flash program or the code, you can carefully read the following tutorial.
It only costs 20 yuan to DIY a digital clock that is always accurate. Quick production tutorial and principle explanation_Bilibili婷_bilibili
I am new to Arduino and PCB, please don’t criticize me, thank you!