The schematic diagram for the ESP8266 WeMos D1 Mini board:sch_d1_mini_v3.0.0
Some notes on the schematic:
- The voltage regulator is a ME6211 which has a maximum input voltage of 6.5 V. This input pin is directly wired to the 5V pin which means you can power the WeMos D1 Mini at a maximum of 6.5 V.
- A 0.5 A fuse connects the 5V pin and the USB VBUS. 0.5A or 500 mA is the maximum output current from desktop computer USBs. Using a higher current external power supply through the microUSB will not give higher current to the WeMos D1.
- The USB-serial chip is a CH 340G. For interfacing problems with USB, download the CH340 driver.
- There is an external 4MB flash memory communicating with the ESP8226 through SPI.
- Deep sleep solder joint connects RST to GPIO16.