Arduino 出現下面的錯誤：
error: espcomm_upload_mem failed
REF Link : https://github.com/esp8266/Arduino/issues/2428
Thanks for the suggestion. According to the link you sent, I should have the following:
GPIO 0: LOW
GPIO 15: LOW
Option : GPIO 2: HIGH
The D1 mini schematic shows that GPIO 0 and 2 have 10k pull-up resistors and GPIO 15 has a pull-down. So, I'll try with a pull-down between Pin D3 (GPIO 0) and GND tomorrow morning and report back. I already tried with a 4.7k (only loose resistor available on hand), which did not change the reported Arduino output. However, the 4.7k pull-down & 10k pull-up might not have created a sufficiently low voltage divider (~1.5V if my math is correct).
More REF:
AFAIK there is no way, whatsoever, of soft-bricking an ESP8266, maybe you have broken a resistor or something reset-circuit and that causes your problem -- it looks to me like the IDE or the esptool isn't able to reset the board into programming-mode. You could manually place the ESP into UART programming-mode using pull-up and pull-down resistors according to https://zoetrope.io/tech-blog/esp8266-bootloader-modes-and-gpio-state-startup before trying to flash something, then when flashed remove the resistors and reset the board and see if it works.
More REF:
Thanks for the suggestion, @WereCatf! Fixed by putting a 10 Ohm resistor between pins D3 (DIO 0) and GND! Seems as though the reset & programming circuit pull-down timing, that I had relied upon for so long, is off (see right side of USB to UART section of the Wemos D1 mini schematic)