After having played with the WEMOS D1 mini I needed to switch to the bare-bone ESP12E device so that I can get a feel for it and integrate it into a custom PCB design. This is not easy, as the ESP12E pinning is not compatible with a breadboard. This is the solution I came up with:
After creating my ESP12E on a stick, I plugged it into the breadboard to see if all was working.
I had been programming my Arduino UNO with my Adafruit EZ-LINK (serial over bluetooth module) successfully so I also tried to use this for the ESP. Turns out that this does not work! I kept getting strange error messages when trying to upload to the board. After loosing about 1 day trying to figure out why this did not work I figured out that it was the EZ-LINK that was the problem, it does something to the data that messes the upload cycle up!
After replacing the Adafruit EZ-Link with a normal USB to serial module upload started working correctly.
Just remember the following hardware connections:
1. GPIO15 put it to ground
2. EN(able-) put it to VCC
3. VCC to VCC of course
4. GND to GND of course
5. TX => RX of the serial/USB convertor
6. RX -> TX of the serial/USB convertor
Before hitting upload
=> put GPIO0 to ground
=> put RST temp to ground
=> this resets the device and puts it in “upload mode”
=> you can leave GPIO0 to ground after upload, it does work, however if the device would be reset the