I have a problem with communication between my PC (RAK Serial Port Tool) and the RAK3172 module. When I connect to the module and power it on, I receive some kind of message. However, after that, I can’t receive any answer from the module. One time it worked; when I sent “AT,” the module responded with “OK,” but I can’t repeat it. How can I solve this problem?
Reset is directly connected to 3.3V.
VDD - 3.3V
I tried update firmware but I have timeout error.
I have this same results on two different modules.
I tried two different USB-UART converters. (but this same type)
Here is a screenshot of what I receive when the module is powered on:
In your screenshot I see some correct response and a lot of random characters.
I am guessing your connection to the RAK3172 is not stable.
You pin connections are correct.
Another possible cause:
What firmware is on the RAK3172? Is it our RUI3 AT command firmware or a custom application?
If it is a custom application, could it be that you setup the Serial port with the wrong parameters?
I don’t make any changes. I just take it out of the box and try to communicate with it.
Sometimes I can communicate with it. If the module initialization procedure is successful, it works, but if not, I see these noise letters.
Now I can’t obtain screens, but when it works successfully, I can send for example “AT” and it responds “OK”. It works with other commands as well.
I added 100nF, 10uF and 10uF between VDD and GND and it still doesn’t work properly, but I think it works better with these capacitors.
Im using STM32 nucleo board as my power suply but it doesnt works with laboratory power supply too.
I have two these same modules and I have this same problem on both.
Here yoy can see when i reseted module and on begginig it doesnt works, next reset - it works, next reset - works, next doesnt works:
