DrAzzy:
Which is useful to the OP how?He wishes to upload via serial using the bootloader, not via ISP using the spi pins.
"Arduino Mega as the main MCU in a project, and it has both SPI and UART connections to an ESP12 module"
DrAzzy:
Which is useful to the OP how?He wishes to upload via serial using the bootloader, not via ISP using the spi pins.
"Arduino Mega as the main MCU in a project, and it has both SPI and UART connections to an ESP12 module"