<s>
The	O
ESP8266	B-Device
is	O
a	O
low-cost	O
Wi-Fi	O
microchip	O
,	O
with	O
built-in	O
TCP/IP	B-Protocol
networking	I-Protocol
software	I-Protocol
,	O
and	O
microcontroller	B-Architecture
capability	O
,	O
produced	O
by	O
Espressif	O
Systems	O
in	O
Shanghai	O
,	O
China	O
.	O
</s>
<s>
This	O
small	O
module	O
allows	O
microcontrollers	B-Architecture
to	O
connect	O
to	O
a	O
Wi-Fi	O
network	O
and	O
make	O
simple	O
TCP/IP	B-Protocol
connections	O
using	O
Hayes-style	O
commands	O
.	O
</s>
<s>
The	O
ESP8285	B-Device
is	O
a	O
similar	O
chip	O
with	O
a	O
built-in	O
1MiB	O
flash	O
memory	O
,	O
allowing	O
the	O
design	O
of	O
single-chip	O
devices	O
capable	O
of	O
connecting	O
via	O
Wi-Fi	O
.	O
</s>
<s>
These	O
microcontroller	B-Architecture
chips	O
have	O
been	O
succeeded	O
by	O
the	O
ESP32	B-Device
family	O
of	O
devices	O
.	O
</s>
<s>
The	O
pinout	B-Application
is	O
as	O
follows	O
for	O
the	O
common	O
ESP-01	O
module	O
:	O
</s>
<s>
GPIO	B-Architecture
2	O
,	O
General-purpose	B-Architecture
input/output	I-Architecture
No	O
.	O
</s>
<s>
GPIO	B-Architecture
0	O
,	O
General-purpose	B-Architecture
input/output	I-Architecture
No	O
.	O
</s>
<s>
In	O
October	O
2014	O
,	O
Espressif	O
Systems	O
released	O
a	O
software	B-Application
development	I-Application
kit	I-Application
(	O
SDK	O
)	O
for	O
programming	O
the	O
chip	O
directly	O
,	O
which	O
removed	O
the	O
need	O
for	O
a	O
separate	O
microcontroller	B-Architecture
.	O
</s>
<s>
Since	O
then	O
,	O
there	O
have	O
been	O
many	O
official	O
SDK	O
releases	O
from	O
Espressif	O
;	O
Espressif	O
maintains	O
two	O
versions	O
of	O
the	O
SDK	O
—	O
one	O
that	O
is	O
based	O
on	O
FreeRTOS	B-Operating_System
and	O
the	O
other	O
based	O
on	O
callbacks	O
.	O
</s>
<s>
An	O
alternative	O
to	O
Espressif	O
's	O
official	O
SDK	O
is	O
the	O
open-source	O
ESP-Open-SDK	O
that	O
is	O
based	O
on	O
the	O
GNU	B-Application
Compiler	I-Application
Collection	I-Application
(	O
GCC	B-Application
)	O
toolchain	O
,	O
maintained	O
by	O
Max	O
Filippov	O
.	O
</s>
<s>
Another	O
alternative	O
is	O
the	O
"	O
Unofficial	O
Development	B-Application
Kit	I-Application
"	O
by	O
Mikhail	O
Grigorev	O
.	O
</s>
<s>
With	O
this	O
core	O
,	O
the	O
ESP8266	B-Device
CPU	O
and	O
its	O
Wi-Fi	O
components	O
can	O
be	O
programmed	O
like	O
any	O
other	O
Arduino	O
device	O
.	O
</s>
<s>
—	O
An	O
open-source	O
BASIC-like	O
interpreter	O
specifically	O
tailored	O
for	O
the	B-Operating_System
Internet	I-Operating_System
of	I-Operating_System
Things	I-Operating_System
(	O
IoT	B-Operating_System
)	O
.	O
</s>
<s>
ESP	B-Device
Easy	I-Device
—	O
Developed	O
by	O
home	O
automation	O
enthusiasts	O
.	O
</s>
<s>
—	O
ESPHome	O
is	O
a	O
system	O
to	O
control	O
your	O
ESP8266/ESP32	O
by	O
simple	O
yet	O
powerful	O
configuration	O
files	O
and	O
control	O
them	O
remotely	O
through	O
home	O
automation	O
systems	O
.	O
</s>
<s>
—	O
Open-source	O
FreeRTOS-based	O
ESP8266	B-Device
software	O
framework	O
.	O
</s>
<s>
—	O
Free	O
and	O
open	O
(	O
as	O
much	O
as	O
possible	O
)	O
integrated	O
SDK	O
for	O
ESP8266/ESP8285	O
chips	O
.	O
</s>
<s>
Espruino	B-Device
—	O
An	O
actively	O
maintained	O
JavaScript	O
SDK	O
and	O
firmware	O
,	O
closely	O
emulating	O
Node.js	B-Language
.	O
</s>
<s>
Supports	O
a	O
few	O
MCUs	O
,	O
including	O
the	O
ESP8266	B-Device
.	O
</s>
<s>
—	O
Open-source	O
ESP8285/ESP8266	O
firmware	O
.	O
</s>
<s>
—	O
Port	O
of	O
Jones	O
Forth	O
to	O
the	O
ESP8266	B-Device
microcontroller	B-Architecture
.	O
</s>
<s>
—	O
A	O
port	O
of	O
MicroPython	B-Language
(	O
an	O
implementation	O
of	O
Python	B-Language
for	O
embedded	O
devices	O
)	O
to	O
the	O
ESP8266	B-Device
platform	O
.	O
</s>
<s>
Mongoose	B-Device
OS	I-Device
—	O
An	O
open-source	O
operating	O
system	O
for	O
connected	O
products	O
.	O
</s>
<s>
Supports	O
ESP8266	B-Device
and	O
ESP32	B-Device
.	O
</s>
<s>
—	O
Forth-inspired	O
programming	O
language	O
for	O
the	O
ESP8266	B-Device
.	O
</s>
<s>
—	O
A	O
version	O
of	O
the	O
Lisp	B-Language
programming	I-Language
language	I-Language
specifically	O
designed	O
to	O
run	O
on	O
processors	O
with	O
a	O
limited	O
amount	O
of	O
RAM	O
.	O
</s>
<s>
—	O
A	O
subset	O
of	O
Microsoft	O
's	O
widely-used	O
Visual	O
Basic	O
6	O
,	O
which	O
has	O
been	O
adapted	O
as	O
a	O
control	O
language	O
for	O
the	O
ZX	O
microcontroller	B-Architecture
family	O
and	O
the	O
ESP8266	B-Device
.	O
</s>
<s>
Zerynth	B-Language
—	O
IoT	B-Operating_System
framework	O
for	O
programming	O
ESP8266	B-Device
and	O
other	O
microcontrollers	B-Architecture
in	O
Python	B-Language
.	O
</s>
<s>
This	O
is	O
the	O
series	O
of	O
ESP8266-based	O
modules	O
made	O
by	O
Espressif	O
:	O
</s>
<s>
181.5	O
mm2×9	O
castellated	O
U.FL	B-Protocol
socket	O
18	O
×	O
20	O
Differs	O
from	O
ESP-WROOM-02D	O
in	O
that	O
includes	O
an	O
U.FL	B-Protocol
compatible	O
antenna	O
socket	O
connector	O
.	O
</s>
<s>
In	O
the	O
table	O
above	O
(	O
and	O
the	O
two	O
tables	O
which	O
follow	O
)	O
,	O
"	O
Active	O
pins	O
"	O
include	O
the	O
GPIO	B-Architecture
and	O
ADC	O
pins	O
with	O
which	O
external	O
devices	O
can	O
be	O
attached	O
to	O
the	O
ESP8266	B-Device
MCU	O
.	O
</s>
<s>
The	O
"	O
Pitch	O
"	O
is	O
the	O
space	O
between	O
pins	O
on	O
the	O
ESP8266	B-Device
module	O
,	O
which	O
is	O
important	O
to	O
know	O
if	O
the	O
device	O
will	O
be	O
used	O
on	O
a	O
breadboard	O
.	O
</s>
<s>
This	O
is	O
the	O
first	O
series	O
of	O
modules	O
made	O
with	O
the	O
ESP8266	B-Device
by	O
the	O
third-party	O
manufacturer	O
Ai-Thinker	O
and	O
remains	O
the	O
most	O
widely	O
available	O
.	O
</s>
<s>
Novice	O
ESP8266	B-Device
developers	O
are	O
encouraged	O
to	O
consider	O
larger	O
ESP8266	B-Device
Wi-Fi	O
development	O
boards	O
like	O
the	O
NodeMCU	O
which	O
includes	O
the	O
USB-to-UART	O
bridge	O
and	O
a	O
Micro-USB	O
connector	O
coupled	O
with	O
a	O
3.3	O
volt	O
power	O
regulator	O
already	O
built	O
into	O
the	O
board	O
.	O
</s>
<s>
ESP-01S	O
6	O
0.1	O
in	O
2×4	O
DIL	O
PCB	O
trace	O
14.4	O
×	O
24.7	O
1	O
MiB	O
Flash	O
16	O
1.6	O
mm	O
2×9	O
edge	O
connector	O
PCB	O
trace	O
18.0	O
×	O
18.0	O
Uses	O
ESP8285	B-Device
(	O
1	O
MiB	O
built-in	O
flash	O
)	O
.	O
</s>
<s>
ESP-02	O
6	O
0.1	O
in	O
2×4	O
castellated	O
U.FL	B-Protocol
socket	O
14.2	O
×	O
14.2	O
ESP-03	O
10	O
2	O
mm	O
2×7	O
castellated	O
Ceramic	O
17.3	O
×	O
12.1	O
ESP-04	O
10	O
2	O
mm	O
2×4	O
castellated	O
None	O
14.7	O
×	O
12.1	O
ESP-05	O
3	O
0.1	O
in	O
1×5	O
SIL	O
U.FL	B-Protocol
socket	O
14.2	O
×	O
14.2	O
ESP-06	O
11	O
various	O
4×3	O
dice	O
None	O
14.2	O
×	O
14.7	O
Not	O
FCC	O
approved	O
.	O
</s>
<s>
ESP-07	O
14	O
2	O
mm	O
2×8	O
pinhole	O
Ceramic	O
+	O
U.FL	B-Protocol
socket	O
20.0	O
×	O
16.0	O
Not	O
FCC	O
approved	O
.	O
</s>
<s>
ESP-07S	O
14	O
2	O
mm	O
2×8	O
pinhole	O
U.FL	B-Protocol
socket	O
17.0	O
×	O
16.0	O
FCC	O
and	O
CE	O
approved	O
.	O
</s>
<s>
Modern	O
ESP8266	B-Device
boards	O
like	O
the	O
NodeMCU	O
are	O
easier	O
to	O
work	O
with	O
and	O
offer	O
more	O
GPIO	B-Architecture
pins	O
.	O
</s>
<s>
+	O
Name	O
Active	O
pins	O
Pitch	O
Form	O
factor	O
LEDs	O
Antenna	O
Shielded	O
Dimensions	O
(	O
mm	O
)	O
NotesBolt	O
IoT	B-Operating_System
14	O
0.1	O
in	O
2×14	O
DIL	O
PCB	O
trace	O
30	O
×	O
40	O
Comes	O
with	O
an	O
onboard	O
SD	O
card	O
and	O
features	O
like	O
Lib-Discovery	O
and	O
Fail	O
Safe	O
Mode	O
.	O
</s>
<s>
Has	O
its	O
own	O
cloud	O
for	O
IoT	B-Operating_System
.	O
</s>
<s>
Olimex	O
MOD-WIFI-ESP8266	O
2	O
0.1	O
in	O
UEXT	O
module	O
PCB	O
trace	O
Only	O
RX/TX	O
are	O
connected	O
to	O
UEXT	O
connector	O
.	O
</s>
<s>
Olimex	O
MOD-WIFI-ESP8266-DEV	O
20	O
0.1	O
in	O
2×11	O
DIL	O
+	O
castellated	O
PCB	O
trace	O
33	O
×	O
23	O
All	O
available	O
GPIO	B-Architecture
pins	O
are	O
connected	O
,	O
also	O
has	O
pads	O
for	O
soldering	O
UEXT	O
connector	O
(	O
with	O
RX/TX	O
and	O
SDA/SCL	O
signals	O
)	O
.	O
</s>
<s>
NodeMCU	O
DEVKIT	B-Application
14	O
0.1	O
in	O
2×15	O
DIL	O
PCB	O
trace	O
49	O
×	O
24.5	O
Uses	O
the	O
ESP-12	O
module	O
;	O
includes	O
USB	O
to	O
serial	O
interface	O
.	O
</s>
<s>
Adafruit	O
Huzzah	O
ESP8266	B-Device
breakout	O
14	O
0.1	O
in	O
2×10	O
DIL	O
PCB	O
trace	O
25	O
×	O
38	O
Uses	O
the	O
ESP-12	O
module	O
.	O
</s>
<s>
SparkFun	O
ESP8266	B-Device
Thing	O
WRL-13231	O
12	O
0.1	O
in	O
2×10	O
DIL	O
PCB	O
trace	O
+	O
U.FL	B-Protocol
socket	O
58	O
×	O
26	O
FTDI	O
serial	O
header	O
,	O
Micro-USB	O
socket	O
for	O
power	O
,	O
includes	O
Li-ion	O
battery	O
charger	O
.	O
</s>
<s>
ArduCAM	O
ESP8266	B-Device
UNO	O
12+	O
0.1	O
in	O
Arduino	O
Uno	O
PCB	O
trace	O
53.4	O
×	O
68.6	O
Uses	O
the	O
AI	O
Thinker	O
's	O
ESP8266MOD	O
module	O
and	O
features	O
Micro-USB	O
port	O
,	O
Battery	O
pins	O
,	O
Camera	O
pins	O
and	O
uSD	O
card	O
all	O
on	O
the	O
same	O
board	O
.	O
</s>
<s>
WeMos	O
D1	O
mini	O
Lite	O
12	O
0.1	O
in	O
2×8	O
DIL	O
PCB	O
trace	O
25.6	O
×	O
34.2	O
Based	O
on	O
the	O
ESP8285	B-Device
,	O
an	O
ESP8266	B-Device
with	O
1	O
MiB	O
flash	O
built-in	O
;	O
has	O
Micro-USB	O
socket	O
.	O
</s>
<s>
WeMos	O
D1	O
mini	O
Pro	O
12	O
0.1	O
in	O
2×8	O
DIL	O
Ceramic	O
and	O
U.FL	B-Protocol
socket	O
25.6	O
×	O
34.2	O
Uses	O
ESP8266EX	O
chip	O
;	O
has	O
Micro-USB	O
socket	O
,	O
U.FL	B-Protocol
antenna	O
connector	O
,	O
and	O
16	O
MiB	O
flash.ESPert	O
ESPresso	O
Lite	O
16	O
0.1	O
in	O
2×8	O
DIL	O
PCB	O
trace	O
26.5	O
×	O
57.6	O
Uses	O
the	O
ESP-WROOM-02	O
module	O
.	O
</s>
<s>
Produced	O
in	O
limited	O
quantity	O
as	O
beta	O
version.ESPert	O
ESPresso	O
Lite	O
V2.0	O
24	O
0.1	O
in	O
2×10	O
DIL	O
PCB	O
trace	O
28	O
×	O
61	O
Improved	O
version	O
of	O
ESPresso	O
Lite.In-Circuit	O
ESP-ADC	O
18	O
0.1	O
in	O
2×9	O
DIL	O
U.FL	B-Protocol
socket	O
22.9	O
×	O
14.9	O
Uses	O
ESP8266EX	O
chip	O
.	O
</s>
<s>
Geek	O
Wave	O
Solution	O
IOT	B-Operating_System
WROOM-02	O
Dev	O
.	O
</s>
<s>
Development	O
board	O
with	O
Espressif	O
ESP8266	B-Device
ESP-12E	O
and	O
separate	O
board	O
for	O
CH340G	O
USB	O
interface	O
.	O
</s>
<s>
In	O
2020	O
,	O
Espressif	O
announced	O
a	O
new	O
chip	O
ESP32-C3	O
,	O
which	O
is	O
pin-compatible	O
with	O
ESP8266	B-Device
.	O
</s>
<s>
It	O
is	O
based	O
on	O
a	O
single	O
core	O
RISC-V	B-Device
32-bit	O
CPU	O
with	O
a	O
clock	O
speed	O
of	O
up	O
to	O
160	O
MHz	O
.	O
</s>
