david_prentice:
Why so complicated?
You could supply the ESP8266 from the 3.3V output on the Mega. Of course the 3.95" shield obscures the 3.3V pin.Likewise, you could power the Mega from the 5V output of the MB102 and the ESP8266 from the 3.3V output.
I am very worried about a 12V wall-wart. The MB102 regulator will get warm. A 6V or 7.5V wall-wart would be safer.The 3.95" shield takes about 200mA. Most current goes to the backlight.
I have not heard anything about level-shifters for the ESP8266. If you drive it from the 5V Mega pins, you will back-feed voltage. You must have a level-shifter chip or resistors.
We really do need to see a schematic as well as your code.
David.
Thanks for the inputs . For the ESP8266 I have level shifter using the resistors. I powered the ESp8266 separately because I read in many blogs that the arduino boards wont be able to provide the sufficient current to the ESP8266 and better to have separate power supply. I have used level shifter for the ESp8266 as well .
I want to know a few more details of the TFT LCD. Is it really required to power up the 3.3v and 5v pins in LCD if I just want to use module excluding the SD card and the touch. I just want that to be a screen to display the data.
Now that I have connected the D0-D8 to the Mega PINS 2-9 . Connected the 5 and 3.3v and GND.
And the A0-A4 in Arduino MEGA for the LCD_RD - LCD_RST in LCD.