I bought a couple of Soil Moisture Sensors V1.1 (http://wiki.aprbrother.com/wiki/ESP_Soil_Moisture_Sensor#Hardware_Rev1) and the USBtoUART (https://pbs.twimg.com/media/CyetkglUQAAfXSb.jpg).
I started playing with it, follwing the instructions step by step (http://wiki.aprbrother.com/wiki/ESP_Soil_Moisture_Sensor_Using_Arduino_IDE). However, I got the next error message:
warning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
The code was compiled well, but it was not transfer to the ESP board.
Do you have any clue?
Thanks in advance,