Vin pin vs USB vs Barrel connector: Wemos D1 R2. @Majenko says in the leading (19 Upvote) answer here not to use VIN and USB socket at the same time. You must never ever connect VIN to a power source and connect the USB socket. That can destroy the USB port in your computer. There is zero back-powering protection on [LoLin v3 board] board. Make S2 boards into Device Firmware Upgrade (DFU) mode. Hold on Button 0. Press Button Reset. Release Button 0 When you hear the prompt tone on usb reconnection. Flash using esptool.py. esptool.py --port PORT_NAME erase_flash esptool.py --port PORT_NAME --baud 1000000 write_flash -z 0x1000 FIRMWARE.bin. The sensor uses a Wemos D1 Mini and PRO and a Non-invasive Split Core Current Transformer type 100A SCT-013-000, available on eBay. You can use Current Transformer type calibrated SCT-013-030 (30A), SCT-013-050 (50A) and others. The 5V input from the USB socket passes through a 0.5A 'fuse' and a diode, before being distributed as a 5V supply, for both the power input to the 5V-to-3.3V regulator and the 5V 'board output' pin 9. So the fuse will limit the incoming current to to 0.5A, and some of that current must be 'reserved ' for the processor. The Wemos D1 mini is ideal as it can be powered using 5V DC, the same voltage that will power the WS2812b LED strip. You can easily swap out the Wemos D1 mini with a NodeMCU as this micro-controller also accepts 5V input voltage. Another (cheaper) alternative is the popular ESP-01 module. The NodeMCU has a slightly longer footprint than the Wemos D1 Mini, measuring 48.0mm long and 23.88mm wide. It weighs about 50 grams compared to the Wemos D1 mini's 3 grams. Finally, the NodeMCU is slightly more expensive than the Wemos D1 mini, at around $8 per chip. But like Wemos, NodeMCU can be purchased from Amazon, Aliexpress and Banggood. Setup WEMOS D1 Mini using the Arduino IDE. Begin by connecting your WEMOS D1 mini to your computers USB port to configure the device. 1.-. Download the Arduino IDE if you do not already have it. 1a. - Open the Arduino IDE, select Files -> Preferences and enter the URL below into Additional Board Manager URLs field. This 3D printed case is specifically tailored to accommodate the WeMos D1 mini variant of the ESP8266 microcontroller with various temperature or similar sensors. The model is designed to meet a range of preferences and requirements. It incorporates two main components that click together for an effortless assembly. Aliexpress - ESP8266 - WeMos D1 Mini Wi-Fi Board. $2.23. out of stock. BUY NOW. Aliexpress. Recommended reading: Best ESP8266 Wi-Fi Development Board. The WeMos D1 Mini offers 4MB flash memory, 11GPIOs, 1 ADC pin in a minimal and small setup. So, if you need something that consumes less power for a more economical project, this is a good option. Hello, I'm trying to reliably power a D1 Mini from solar charged battery according to this video: 436 How to use Voltage Supervisors to protect ESP32, Raspberry Pi, and Batteries - YouTube I've built an experimental prototype like on this sketch: Because of the drop on the voltage regulator, I decided the voltage at which the MCU should be switched on should be above ~3.8V. The voltage divider 4wo3P.