<s>
Apache	B-Device
Mynewt	I-Device
is	O
a	O
modular	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
for	O
connected	O
Internet	B-Operating_System
of	I-Operating_System
things	I-Operating_System
(	O
IoT	B-Operating_System
)	O
devices	O
that	O
must	O
operate	O
for	O
long	O
times	O
under	O
power	O
,	O
memory	O
,	O
and	O
storage	O
constraints	O
.	O
</s>
<s>
It	O
is	O
free	B-License
and	I-License
open-source	I-License
software	I-License
incubating	O
under	O
the	O
Apache	O
Software	O
Foundation	O
,	O
with	O
source	O
code	O
distributed	O
under	O
the	O
Apache	B-Application
License	I-Application
2.0	I-Application
,	O
a	O
permissive	O
license	O
that	O
is	O
conducive	O
to	O
commercial	O
adoption	O
of	O
open-source	B-Application
software	I-Application
.	O
</s>
<s>
Apache	B-Device
Mynewt	I-Device
is	O
a	O
real-time	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
with	O
a	O
rich	O
set	O
of	O
libraries	B-Library
intended	O
to	O
make	O
prototyping	O
,	O
deploying	O
,	O
and	O
managing	O
32-bit	O
microcontroller	B-Architecture
based	O
IoT	B-Operating_System
devices	O
easy	O
.	O
</s>
<s>
It	O
is	O
highly	O
composable	O
,	O
to	O
allow	O
building	O
embedded	B-Architecture
system	I-Architecture
applications	O
(	O
e.g.	O
,	O
locks	O
,	O
medical	O
devices	O
,	O
industrial	O
IoT	B-Operating_System
)	O
across	O
different	O
types	O
of	O
microcontrollers	B-Architecture
.	O
</s>
<s>
The	O
OS	O
is	O
designed	O
for	O
connectivity	O
,	O
and	O
comes	O
with	O
a	O
full	O
implementation	O
of	O
the	O
Bluetooth	B-General_Concept
low	I-General_Concept
energy	I-General_Concept
4.2	O
stack	O
.	O
</s>
<s>
With	O
the	O
addition	O
of	O
BLE	O
(	O
supporting	O
all	O
Bluetooth	O
4.2	O
compliant	O
security	O
features	O
except	O
privacy	O
)	O
and	O
various	O
utilities	O
such	O
as	O
the	O
default	O
file	B-Application
system	I-Application
,	O
console	O
,	O
shell	O
,	O
logs	O
,	O
stats	O
,	O
etc.	O
,	O
the	O
image	O
size	O
is	O
approximately	O
96	O
KB	O
for	O
the	O
Nordic	O
nRF51822	O
Bluetooth	O
SoC	O
.	O
</s>
<s>
This	O
size	O
metric	O
excludes	O
the	O
boot	B-Operating_System
loader	I-Operating_System
image	O
.	O
</s>
<s>
Hardware	B-Operating_System
abstraction	I-Operating_System
layer	I-Operating_System
with	O
support	O
for	O
CPU	O
time	O
,	O
analog-to-digital	O
converter	O
(	O
ADC	O
)	O
,	O
digital-to-analog	O
converter	O
(	O
DAC	O
)	O
,	O
general-purpose	B-Architecture
input/output	I-Architecture
(	O
GPIO	B-Architecture
)	O
,	O
Inter-Integrated	O
Circuit	O
(	O
I2C	O
)	O
,	O
pulse-width	B-Algorithm
modulation	I-Algorithm
(	O
PWM	O
)	O
,	O
serial	B-Protocol
port	I-Protocol
,	O
Serial	B-Architecture
Peripheral	I-Architecture
Interface	I-Architecture
Bus	I-Architecture
(	O
SPI	O
)	O
,	O
universal	O
asynchronous	O
receiver/transmitter	O
(	O
UART	O
)	O
.	O
</s>
<s>
The	O
first	O
network	B-Protocol
stack	I-Protocol
available	O
in	O
Mynewt	O
is	O
Bluetooth	B-General_Concept
low	I-General_Concept
energy	I-General_Concept
and	O
is	O
called	O
NimBLE	O
.	O
</s>
<s>
For	O
example	O
,	O
the	O
BLE	O
throughput	O
can	O
be	O
adjusted	O
by	O
changing	O
the	O
connection	O
intervals	O
,	O
data	O
packet	O
size	O
,	O
packet	O
queue	B-Application
size	O
etc	O
.	O
</s>
<s>
The	O
operating	B-General_Concept
system	I-General_Concept
is	O
designed	O
for	O
cross-platform	B-Operating_System
use	O
in	O
embedded	B-Architecture
systems	I-Architecture
(	O
devices	O
)	O
and	O
microcontrollers	B-Architecture
.	O
</s>
<s>
The	O
project	O
includes	O
the	O
Newt	O
Tool	O
which	O
is	O
a	O
command-line	B-Application
interface	I-Application
(	O
CLI	O
)	O
based	O
smart	O
source	O
package	B-Application
manager	I-Application
system	O
for	O
embedded	B-Architecture
systems	I-Architecture
development	O
.	O
</s>
