The following files are daily firmware for ESP32-based boards, with separate firmware for boards with and without external SPIRAM. Non-SPIRAM firmware will work on any board, whereas SPIRAM enabled firmware will only work on boards with 4MiB of external pSRAM.
Program your board using the esptool.py program, found here. If you are putting MicroPython on your board for the first time then you should first erase the entire flash using:
esptool.py --chip esp32 --port /dev/ttyUSB0 erase_flash
From then on program the firmware starting at address 0x1000:
esptool.py --chip esp32 --port /dev/ttyUSB0 --baud 460800 write_flash -z 0x1000 esp32-20190125-v1.10.bin
Firmware is provided using either ESP-IDF v3.x or v4.x. If in doubt use v4.x.
Firmware built with ESP-IDF v4.x, with support for BLE and PPP, but no LAN.
Firmware built with ESP-IDF v3.x, with support for BLE, LAN and PPP. MicroPython v1.14 was the last version to support ESP-IDF v3.x.