$5 Wemos D1 mini Pro ESP8266 Board includes 16MB Flash

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.

Wemos_D1_mini_ProWemos D1 mini Pro specifications:

  • 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

Wemos-D1-mini-Pro-ESP8266-BoardBeside 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.

Wemos D1 mini Pro is sold on Aliexpress for $5 plus shipping ($1.36 in my case) with male and female headers. The product is not listed on Wemos.cc website yet, but soon should be.

Thanks to Zoobab for the tip.

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.

Support CNX Software - Donate via PayPal, become a Patron on Patreon, or buy review samples
Subscribe
Notify of
guest
15 Comments
oldest
newest most voted
zoobab
4 years ago

CP2104, they could have at least exposed the GPIO pins of that chip:

https://github.com/ondrej1024/crelay
https://github.com/GBert/CP2104_GPIO

Occ
Occ
4 years ago

These I/0 are controlled by the USB right? If so how would they be useful to the board?

Demetris
Demetris
4 years ago

I didn’t get one point:
– switch by re-soldering resistor 0(zero) ohm
You need to remove 0 ohm to use external antenna or remove it so you can use the internal ceramic one?
And whats the problem keep the build-in antenna and use both(int+ext)?

Occ
Occ
4 years ago

You move the 0 ohm resistor to connect the external antenna connector instead on onboard chip antenna. Using both would create impedance mismatch and result in poor performance

paul
paul
4 years ago

Can anyone remind me of the type of External antenna plug required to fit that socket ? (and perhaps an online seller of good hi-gain antenna with that plug to save buying adaptor with associated loss)

@cnx Do the Shields for the previous wemos Di mini version fit the Di mini pro ?

Jeremy Therin
4 years ago

Demetris :
And whats the problem keep the build-in antenna and use both(int+ext)?

The signal would be poor or may not work because impedance will not match specifications.

paul
paul
4 years ago

@Jean-Luc Aufranc (CNXSoft) Thanks for that reply. While waiting for it I did some googling which agreed with your advice, so added a number of shields to aliexpress basket and sent their ‘Ou Chen’ the following questions on aliexpress message: 1) Is the Ext Ant socket u.fl/IPEX ? 2) Are the shields for your previous ‘Di mini’ compatible with the new ‘Pro’ 3) Will the D1 mino Pro work ok with many Di mini shields stacked ? 4) I am looking to add 2 channel 12bit ADC and a photodetector to cound LED pulses from a Mains Power Utility Meter… Read more »

paul
paul
4 years ago

@paul
I got a reply from Wemos this morning confirming points 1, 2, 3

paul
paul
4 years ago

@cnx the day after your article saying Wemos D1 mini was one of your favourites , I clicked on your link to Aliexpress for the D1 mini Pro and purchased it, plus some D1 mini Shields, about 12 items. Confirmation of my orders arrived promptly 20-40 day delivery to UK. I have not used Aliexpress before, and as timing is tight before I go to Brazil, thought to ask them if I can continue purchasing items on my UK creditcard for delivery to Brazil (which their site shows they deliver to) once I Add my Brazil address to my account.… Read more »

paul
paul
4 years ago

@Jean-Luc Aufranc (CNXSoft) Yes, I sent enquiries to Sellers via Aliexpress. Wemos replied 7 September. However, it may be uncommon for customers to alter their Delivery Address to different country without changing creditcard. I thought only Ali may know the answer, as payments go thru Ali, ‘sellers’ may not know where customers cards registered. As I found no contact method for Ali itself, I sent above enquiry to seller Excellence Electronic where I placed most recent order (12 Nov) but their reply simply “Sorry, parcels can only be sent to the registered address”, just states the obvious, doesn’t say if… Read more »

paul
paul
4 years ago

@Jean-Luc Aufranc (CNXSoft) UK Postal redirection to Brazil even for letters is astronomic, many 100 of times more than the value of goods ordered, and would of course destroy the all-important guarantee of ‘no receipt, no payment’ offered by all payment processor I have used. FYI UK post to Brazil typ 3 to 4 weeks unless paying extra. Guaranteed delivery is important: 2 items I ordered recently thru Amazon never arrived. Not all items from China are tracked post. (The Di Mini Pro & Shields have arrived) Reason I revisited this thread, is you said Aliexpress should be contactable this… Read more »

Advertisements