I would be glad if anyone could help me to increase the range of my 433mhz modules. I am planning to set up a moisture, temperature and pressure sensor for my plants. The data should be sent zu the receiver about 15-20 meters away. Most probably in line of sight. There wont be too much in between. The best I have been getting so far was about 10 meters (probably even less) line of sight. With inconsistent results and more often than not much less than 10 meters.
Here is what I am using and what I have done so far. To test I just want to transmit a string of 18 letters.
I have these 433mhz modules (I have heard they are crap, but I have also read from many people that have been able to get good results with similar modules):
Transmitter attached to Arduino pro mini and Receiver attached to Arduino Nano. Both running on 5V. Unfortunately I wont be able to use more than 5V.
At first I used the following library, because the description sounded very promising:
After a while I tried the RadioHead library, which increased the range considerably:
I tried all of those antennas:
Coil loaded antenna:
and a 4/Wave straight and coiled antenna.
I don't know what else I should do to increase the range even further without using a dipol antenna or a lora module.
Does anyone have an idea how to get a much better range? I have heard of people talking about 50 or more meters.
Your help is greatly appreciated.