I've programmed my ESP-01 as an standalone AP, and I've done some outdoor line of sight range tests,
I had a maximum range of 730 feet ( about 222.5m) when the module was set on a porch about 4 feet off of the ground.
But here's the weird part:
When I set my ESP-01 on the ground, then range is reduced to a mere 150 feet ( about 45m) or so.
This range reduction occurs both on short grass, and flat road. Zero obstacles in the way.
I tested this with battery positive wire to the four middle pins and to the regular VCC pin, and GND pin to battery ground as it appeared Chuck Lohr did.
CNLohr was able to get 1,200 feet or so with the same module in his tests.
So 4 questions:
1. Why is my range dramatically reduced when the module is on the ground?
2. How can I improve this range?
3. Has anyone done range tests for the ESP-201 using an external antenna?
4. If ESP-201 with external antenna range tests have been done, what is the maximum distance you are getting?