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ESP8266 ESP-201 module - first impressions

Submitted by smarpldotcom on Tue, 01/27/2015 - 17:30

Overview

I've been experimenting with different ESP8266 (mostly ESP-01) modules already for some time. As soon as ESP-201 became available I ordered them and yesterday received the long awaited package. And I was not disappointed. The ESP-201 module is a really good choice for prototyping ESP8266 projects.

The size of the board is 25x35mm, totally it has 26 pins with 0.1' (2.54mm) pin spacing. ESP-201 is equipped with on-board antenna and U.FL connector for the external antenna, which also was included in package. See more details on ESP-201 antenna troubleshooting.

Compared to ESP-12 this module has 6 more pins broken out - D0, D1, D2, D3, CLK, CMD (GPIO6-GPIO11). But only two of them (D2, D3) can be used as regular GPIOs after slight hardware modification.

As well as other ESP modules the ESP-201 comes with AT firmware preloaded (mine has 0019000902 version). The vendor appears to be "http://goouuu.com" instead of "ai-thinker" in ESP-01..ESP-12.

Unfortunately some soldering required to make the module breadboard friendly. The UART pins should be moved to the other PCB side. See pictures below.

Before

ESP8266 ESP-201 module bottom view

After

ESP8266 ESP-201 module serial port resoldered

First run

GPIO15 should be pulled down at startup to switch module into boot from flash mode. Other connections are the same as with ESP-01 module (RX<->TX, TX<->RX, RESET<->RTS, GPIO0<->DTR).

Click to view large image

Pin reference

One more issue with ESP-201 module is related to pin labels - they are printed on the bottom side of the board only. So it's hard to find the right pin without documentation when the module is plugged into breadboard.

I created a cheat sheet to make locating pins easier. This looks more like a draft now. I'm going to improve it by adding all possible pin functions.