Hi,
This code was modified from some code I wrote to read INA219 voltage and current monitor chips. I use HC-12 RF modules to get data from various remote sensors. Each sensor has a unique ID This code had an ID of #F So to get a reading I just send the ID characters and that remote sensor sends back the data as text. In this code it skips past looking for the "F" character so just sending an "#" character sends all the time and date information. The code starts by setting the DS3231 to a fixed time and date. Which you will see at the start of the code. so from then on you just send the # character to display the time. You can just use a terminal emulator program such as Tera Term running on a PC.
The .asm file is just a text file so you should be able to read it using any text editor program.
Les.