I´m trying to build a little robot, which would drive around in my garden, and always know its location. To achieve this, I thought about planting 2 stationairy radio transmitters in certain spots, which would be a known distance apart. Now for every "step" the robot makes, it should get a signal from the transmitters. The first one starts and the robot is supposed to rotate an antenna towards the signal, by measuring the RSSI and saving the angle of the strongest signal. Then it should send a "OK" message, and the process should be repeated with the second. After that, it can use the known distance between the 2 emitters, and the 2 measured angles, to calculate its position on a 2D map, relative to the 2 emitters. Now I of course want to get the best radio transmitter (and receiver) for the project. It should be able to read the RSSI, and it should have a range of at least 5 meters. The nrf24l01 for example is just able to check, if its over a certain value, and will then give out a boolean. Obviously too vague for me. Also, I´d like to know what I could expect from said robot. It would be used outside, however, obstacles such as trees, bushes or chairs will still exist. Would the strongest signal still be in a straight line, when going through a tree, or could its reflection from a wall nearby be stronger? And if so, what could I do, to make it work better? Please help me, because I don´t want to make the wrong choices when I´m ordering the parts.
Thanks in advance!