A quick note regarding the ESP8266 based board named Wemos D1 mini.
I bought one of these boards, from Aliexpress for under 4€. It took more or less a month to arrive. I’ve still haven’t too much time to do something with it, but here are my first impressions:
The Wemos D1 mini is, in my opinion a better buy than the ESP-01 and ESP-12, for many things:
– It has all the supporting electronics for power and serial communication:
– Included USB to serial converter CH340G, but with no TX and RX activity leds.
– It can be powered by the mini USB connection, or through a 5V pin, since it has a 5V to 3.3V linear converter
– It also has a 3.3V input/output pin.
– It comes with some modern version of NodeMcu, so it’s ready to be used with the ESPlorer application, just connect to USB and we are ready.
– It includes stack able pins that allows several ways of creating our devices.
But most important is that it can be flashed with alternative firmwares, like Sming, and that’s what I did. Sming applications that I have, like the Wifi Scanner worked just fine and detected several wifi networks on the vicinity.
Also, the Wemos D1 mini has a reset button, but there is no need to use it to flash the device. The RTS and DTR lines of the serial connection are properly mapped to the GPIO0 and RST pins of the ESP-8266 so flashing is automatic. No need to press reset or manipulate pins. I was able to flash the device with several different bit rates like 460800 and 921600. The esptool.py can have some issues detecting the board, from some of the tests that I did, but at the end it flashes the board with no issue.
So, being the double of the price of the ESP-01 and a bit less price difference from the ESP-12, but with the included power and USB-Serial electronics, that are needed to be budgeted and implemented with the other boards, and all on a nice small package, it is by far the best way to enter the ESP-8266 world.