Recently, I found a few HC-12 wireless modules that I had bought a long time ago from my drawer. I intended to use them to create a wireless remote control for a small toy, but during testing, when I connected to the computer and sent data through the serial debugging tool, it froze, although receiving still worked. I thought the module might be broken since it had been unused for a long time, so I didn’t pay much attention to it. However, I needed to use this module again recently, so I decided to test it thoroughly and finally discovered the cause of the problem.Here, I will briefly introduce the tools used in the experiment and the corresponding results. Interested friends might want to try it themselves, as there are many factors that can affect the results.Experiment Process:The main subjects are three identical HC-12 wireless modules, which are 433M wireless transparent transmission modules. They use a microcontroller that communicates with the RF chip via SPI, converting the RF chip’s transmitted and received data into serial transparent data for easier handling.
Additionally, the other main subjects are three different models of USB to TTL serial tools: the CH340 module, the FT232 module, and a multifunctional six-in-one module.
Each USB to TTL module is paired with an HC-12 wireless transparent transmission module, connected in the following order:
During the experiment, all three sets of serial modules were plugged into the computer simultaneously, and three serial terminals were opened to verify data transmission. Since the wireless modules were pre-configured, theoretically, any module sending data should be received by the other modules.The above combinations seem reasonable, but the experimental results were unexpected.Experiment Results:(1) Multifunctional six-in-one module: Normal transmission and reception multiple times.
(2) CH340 module: Normal transmission and reception multiple times.
(3) FT232 module: First transmission was normal, but the second transmission failed.At first, I was surprised to find that this module could actually send data, as it had previously failed to send even once during testing! I thought I would have to discard the documentation. Haha.
So, I tried again, and the result was the same. I felt relieved, as I couldn’t mislead others.
Result Analysis:Although the experiment indicated that the FT232 module had issues when connected to the HC-12, there are still some uncertainties. After all, I only replaced two identical FT232 USB to TTL modules during the experiment and did not use more combinations. Moreover, the HC-12 is an older version purchased a long time ago. Therefore, if any of you have similar modules on hand, feel free to try it out, and I encourage everyone to discuss more.Based on past experience, I have the following suggestions for hardware enthusiasts:① Keep several types of debugging tools handy, especially USB to TTL modules, and try different ones when encountering issues.② Do not blindly trust any debugging tool, even if it is one you have used for a long time. I can trust it 95%, but I still keep 5% skepticism.③ The stranger the problem seems, the more you should think from the simplest perspective; the issue might be right in front of you.