Wemos D1 mini is one of my favorite ESP8266 development boards thanks to its small size, shield support, and low $4 price tag. There’s now a new version of the board – dubbed Wemos D1 mini Pro – with 16MB flash instead of 4MB for the original version, and a few other modifications.
- WiFi 802.11 b/g/n module based on ESP8266EX with 16 MB flash, chip antenna and external antenna connector
- Expansion – Through holes with
- 11x digital input/output pins (3.3V) supporting interrupt/PWM/I2C/one-wire (except D0 pin)
- 1x analog input (3.3V max input)
- Reset and power signals (5V, 3.3V, GND)
- USB – micro USB port
- Misc – Reset button
- Power – 5V via micro USB or 5V pin
- Dimensions – 34.2 x 25.6 mm
- Weight – 2.5 grams
Beside the larger flash, the main differences are listed in a Wemos forum post:
- External antenna connector – switch by re-soldering resistor 0(zero) ohm
- Built-in ceramic antenna – good!
- New CP2104 USB-TO-UART IC – why? more stable?
- Same size as D1 mini, but more light (3.9g -> 2.5g) – for flying devices? 🙂
Wemos D1 mini had a PCB antenna for WiFi, which may explain the lighter weight too, and CH340G instead of CP2104. The Pro board can run both NodeMCU or Arduino firmware like the original D1 mini board, and I understand the shields are still compatible.
Thanks to Zoobab for the tip.