• Testing r1.0 Boards

    Kaspars Dambis10/27/2018 at 16:36 0 comments

    The first revision prototype boards have arrived. There is something drastically wrong with the 3.3V power regulator wiring. The MCP1702 regulator (pdf) requires a few passives to actually do anything.

    Secondly, the GPIO15 pin has to be tied to GND which is currently missing from the circuit.

    I also received a few of the ESP-12S chips. Here a the instructions for updating the official AT firmware to the latest version 3.0:

    esptool.py --port=/dev/tty.SLAB_USBtoUART write_flash --flash_size 2MB-c1 \
        0x00000 bin/boot_v1.7.bin \
        0x01000 bin/at/1024+1024/user1.2048.new.5.bin \
        0xfe000 bin/blank.bin \
        0x1fc000 bin/esp_init_data_default_v08.bin \
        0x1fb000 bin/blank.bin \
        0x1fe000 bin/blank.bin

    The most important being the --flash_size 2MB-c1 parameter. Note that boot messages are returned at 74880 baud while the AT commands at 115200 baud.

    Finally, we probably need a dedicated RESET button because the flashing button circuit requires a reset to actually enter the UART download mode.