I'm proud to present my Arduino library supporting PMS5003 Air Quality Sensor.
pms5003 library is distributed under Boost Software License 1.0 (BSL-1.0).
- There are some TODOs for next revisions
Release 2.1 brings a lot of changes and improvements:
- API contract (class names and methods) is completely rewritten. It is not compatible with v1.0. Sorry :(
- Minor bugs are fixed (nothing important, release 1.0 should be assumed as stable).
- Added support for sensor hardware pins (pin 3 - SET, pin 6 - RESET).
- Added support for more serial port libraries (inversion of control).
- Added support for unit tests (soon).
- Added support for ISO 14644-1: Classification of air cleanliness.
- Added more diagnostic checks
- Added support for "views" (will be described later) - the most exciting new feature.
Previous release: 1.0 is still available.
There is one interesting fork supporting ESP8266: https://github.com/riverscn/pmsx003
My library supports PMS5003 (checked)
For most Plantover sensors probably it is an easy task to add support.
list of compatible sensors is available as a separate document.
- Library supports all Plantover PMS5003 features (sleep & wake up, passive / active modes, hardware pins),
- Highly customizable:
- It uses almost any serial communication library,
- You have a choice to use or not to use: (C style) global variables or (C++ style) class instances.
- Written from scratch,
- Written in modern C++11 (please do not afraid - works fine with Arduino IDE).
- It is "headers only" library.
- The main goal: Reading data from the sensor does not block. Your process receives the status
OK
orNO_DATA
or some kinds of errors but your process never waits for the data. - Serial port is not managed by the library, it is possible to shut serial driver down, enter sleep mode and so on independently on the PMS5003 sensor.
- Provides support for ISO 14644-1 classification of air cleanliness levels.
pms5003 API description is available as a separate document.
- New methods: some more checks
- #16
write()
will returnPmsStatus
instead ofbool
- #17 add iterators
begin()
andend()
for views - #18
isWorking()
should returntribool
- #19
write(CMD_WAKEUP)
should not delay if already awoken - #20
write()
multiple commands sequentially - Support for platforms
- Support for boards:
- #24 ESP8266
- #25 Add unit tests
pms5003 library is developed using:
- Visual Studio Community 2017 (Windows)
- Arduino IDE for Visual Studio
pms5003 library was successfully checked using:
- Arduino 1.8.5 (Windows)
- Current version uses DrDiettrich' fork of AltSoftSerial Library. Install it.
- pms5003 will not compile using original AltSoftSerial lib.
- pms5003 will not compile using very old Arduino IDE. Please upgrade.
Install pms5003 library.
- PMS5003 Pin 1 (violet): VCC +5V
- PMS5003 Pin 2 (brown): GND
Important: PMS5003 sensor uses 3.3V logic. Use converters if required or make sure your Arduino board uses 3.3V logic too.
- PMS5003 Pin 4 (blue): Arduino pin 9 (there is no choice, it is forced by AltSerial)
- PMS5003 Pin 5 (green): Arduino pin 8 (there is no choice, it is forced by AltSerial)
- Optional
- PMS5003 Pin 3 (white): Arduino pin 7 (can be changed or not connected at all)
- PMS5003 Pin 6 (yellow): Arduino pin 6 (can be changed or not connected at all)
- PMS5003 pin 7 (black) and pin 7 (red) leave not connected
Use the code: examples\p01basic\p01basic.ino
#include <pms.h>
PmsAltSerial pmsSerial;
pmsx::Pms pms(&pmsSerial);
////////////////////////////////////////
void setup(void) {
Serial.begin(115200);
while (!Serial) {}
Serial.println(pmsx::pmsxApiVersion);
if (!pms.begin()) {
Serial.println("PMS sensor: communication failed");
return;
}
pms.setPinReset(6);
pms.setPinSleepMode(7);
if (!pms.write(pmsx::PmsCmd::CMD_RESET)) {
pms.write(pmsx::PmsCmd::CMD_SLEEP);
pms.write(pmsx::PmsCmd::CMD_WAKEUP);
}
pms.write(pmsx::PmsCmd::CMD_MODE_PASSIVE);
pms.write(pmsx::PmsCmd::CMD_READ_DATA);
pms.waitForData(pmsx::Pms::TIMEOUT_PASSIVE, pmsx::PmsData::FRAME_SIZE);
pmsx::PmsData data;
auto status = pms.read(data);
if (status != pmsx::PmsStatus::OK) {
Serial.print("PMS sensor: ");
Serial.println(status.getErrorMsg());
}
pms.write(pmsx::PmsCmd::CMD_MODE_ACTIVE);
if (!pms.isWorking()) {
Serial.println("PMS sensor failed");
}
Serial.print("Time of setup(): ");
Serial.println(millis());
}
////////////////////////////////////////
void loop(void) {
static auto lastRead = millis();
pmsx::PmsData data;
auto status = pms.read(data);
switch (status) {
case pmsx::PmsStatus::OK: {
Serial.println("_________________");
const auto newRead = millis();
Serial.print("Wait time ");
Serial.println(newRead - lastRead);
lastRead = newRead;
auto view = data.particles;
for (auto i = 0; i < view.getSize(); ++i) {
Serial.print(view.getValue(i));
Serial.print("\t");
Serial.print(view.getName(i));
Serial.print(" [");
Serial.print(view.getMetric(i));
Serial.print("] ");
// Serial.print(" Level: ");
// Serial.print(view.getLevel(i));
Serial.print(" | diameter: ");
Serial.print(view.getDiameter(i));
Serial.println();
}
break;
}
case pmsx::PmsStatus::NO_DATA:
break;
default:
Serial.print("!!! Pms error: ");
Serial.println(status.getErrorMsg());
}
}
And the result is (something like this):
Port open
pms5003 2.1
Time of setup(): 2589
_________________
Wait time 906
27 PM1.0, CF=1 [micro g/m3] | diameter: 1.00
34 PM2.5, CF=1 [micro g/m3] | diameter: 2.50
35 PM10. CF=1 [micro g/m3] | diameter: 10.00
23 PM1.0 [micro g/m3] | diameter: 1.00
31 PM2.5 [micro g/m3] | diameter: 2.50
35 PM10. [micro g/m3] | diameter: 10.00
8760 Particles > 0.3 micron [/0.1L] | diameter: 0.30
1780 Particles > 0.5 micron [/0.1L] | diameter: 0.50
70 Particles > 1.0 micron [/0.1L] | diameter: 1.00
18 Particles > 2.5 micron [/0.1L] | diameter: 2.50
1 Particles > 5.0 micron [/0.1L] | diameter: 5.00
1 Particles > 10. micron [/0.1L] | diameter: 10.00
37120 Reserved_0 [???] | diameter: 0.00
To use the library:
- install (download and "Add .ZIP library") DrDiettrich' fork of AltSoftSerial Library
- install (download and "Add .ZIP library") pms5003 library
- include
pms.h
in your code:
#include <pms.h>
Create instance of serial driver
PmsAltSerial pmsSerial;
Create instance of pmsx::Pms object:
- library namespace name is
pmsx
- class name of the object is
Pms
- object is named
pms
- object uses previously created driver
pmsSerial
pmsx::Pms pms(&pmsSerial);
Initialize serial library. If Arduino can't communicate with PMS5003 - there is no sense to perform the next steps.
pms5003 takes care on protocol details (speed, data length, parity and so on).
if (!pms.begin()) {
Serial.println("PMS sensor: communication failed");
return;
}
The next step is to define Arduino pins connected to pms5003:
- SET (pms5003 pin 3, white) (sleep/wakeup)
- RESET (pms5003 pin 6, violet) (sensor reset)
This step is optional.
- If SET pin is not connected - sleep/wakeup commands are executed using serial connection
- If RESET pin is not connected - sleep and then wakeup works like reset
If pins are not connected - just remove appropriate setPinReset
/setPinSleepMode
lines.
pms.setPinReset(6);
pms.setPinSleepMode(7);
The next task is to put sensor in a well known state. There are two aspects of PMS5003 state:
- sleeping/awoken
- passive/active
Both can be examined using isModeActive()
/isModeSleep()
. Please note, that result value is a tristate logic tribool
: Yes / No / I don't know.
Please refer to myArduinoLibrary. It is Arduino port of boost.tribool library description
Please note, that it is possible, that Arduino was restarted for any reason, but PMS5003 was set in a strange state and it was not restarted. It is the reason, that initial states of PMS5003 is "I don't know"
Well known state (awoken and active) can be achieved after sensor hardware reset or sleep+wakeup sequence
if (!pms.write(pmsx::PmsCmd::CMD_RESET)) {
pms.write(pmsx::PmsCmd::CMD_SLEEP);
pms.write(pmsx::PmsCmd::CMD_WAKEUP);
}
The next task is to make sure, that Arduino can communicate with PMS5003. To accomplish the task we are:
- forcing passive mode (PMS5003 sends data only if asked),
- ask for data,
- wait for the response
- and check the response
pms.write(pmsx::PmsCmd::CMD_MODE_PASSIVE);
pms.write(pmsx::PmsCmd::CMD_READ_DATA);
pms.waitForData(pmsx::Pms::TIMEOUT_PASSIVE, pmsx::PmsData::FRAME_SIZE);
pmsx::PmsData data;
auto status = pms.read(data);
if (status != pmsx::PmsStatus::OK) {
Serial.print("PMS sensor: ");
Serial.println(status.getErrorMsg());
}
if (!pms.isWorking()) {
Serial.println("PMS sensor failed");
}
Finally we put back PMS5003 in active mode - it sends data periodically and automatically.
pms.write(pmsx::PmsCmd::CMD_MODE_ACTIVE);
First of all: pms5003 does not block on data read
Try to read the data :
pmsx::PmsData data;
auto status = pms.read(data);
switch (status) {
If there is something interesting: display it:
case pmsx::PmsStatus::OK: {
....
If there are no data: do something else:
case pmsx::PmsStatus::NO_DATA:
break;
In case of error: show the error message:
default:
Serial.print("!!! Pms error: ");
Serial.println(status.getErrorMsg());
}
Lets go back to the situation where there is something interesting:
case pmsx::PmsStatus::OK: {
Data received from PMS5003 (see Appendix I) may be worth attention:
- as a whole (13
pmsx::pmsData_t
numbers, that is 13unsigned int
numbers) - in groups:
- (3 numbers) PM 1.0/2.5/10.0 concentration unit µ g/m3, standard particle, (Compensation Factory) CF=1, (TSI: Technical Specifications for Interoperability))
- (3 numbers) PM 1.0/2.5/10.0 concentration unit µ g/m3 (under atmospheric environment) (looks good for everyday use)
- (6 numbers) the number of particles with diameter beyond 0.3/0.5/1.0/2.5/5.0/10.0 um in 0.1 L of air (very tasty data, it fits into ISO 14644-1 classification of air cleanliness levels)
- (1 number) reserved data, without any real meaning
To get access to them:
auto view = data.raw;
or
auto view = data.concentrationCf;
or
auto view = data.concentration;
or
auto view = data.particles;
Each "view" provides similar interface:
- use
getSize()
to get counter of data in a view:for (auto i = 0; i < view.getSize(); ++i)
- use
.getValue()
to get particular data from indexSerial.print(view.getValue(i));
- use
.getName()
to get description of particular data; for example "Particles > 1.0 micron"Serial.print(view.getName(i));
- use
.getMetric()
to get unit of measure for particular data; for example "/0.1L"Serial.print(view.getMetric(i));
- use
.getDiameter()
to get particle diameter corresponding to particular data; for example 1.0FSerial.print(view.getDiameter(i));
- additionally:
particles
"view" provides.getLevel()
- ISO classification of air cleanlinessSerial.print(view.getLevel(i));
Such a "views" (data partitions) are implemented with no execution time nor memory overhead.
auto view = data.particles;
for (auto i = 0; i < view.getSize(); ++i) {
Serial.print(view.getValue(i));
Serial.print("\t");
Serial.print(view.getName(i));
Serial.print(" [");
Serial.print(view.getMetric(i));
Serial.print("] ");
// Serial.print(" Level: ");
// Serial.print(view.getLevel(i));
Serial.print(" | diameter: ");
Serial.print(view.getDiameter(i));
Serial.println();
}
break;
}
}
If you prefer C style: constants and arrays instead of method calls - please note examples\p02cStyle\p02cStyle.ino
auto view = data.particles;
for (auto i = 0; i < view.SIZE; ++i) {
Serial.print(view[i]);
Serial.print("\t");
Serial.print(view.names[i]);
Serial.print(" [");
Serial.print(view.metrics[i]);
Serial.print("] ");
// Serial.print(" Level: ");
// Serial.print(view.getLevel(i));
Serial.print(" | diameter: ");
Serial.print(view.diameters[i]);
Serial.println();
}
- use
SIZE
to get counter of data in a view:for (auto i = 0; i < view.SIZE; ++i)
- use array index
[]
to get particular dataSerial.print(view[i]);
- use
.names[]
array to get description of particular data; for example "Particles > 1.0 micron"Serial.print(view.names[i]);
- use
.metrics[]
array to get unit of measure for particular data; for example "/0.1L"Serial.print(view.metrics[i]);
- use
.diameters[]
to get particle diameter corresponding to particular data; for example 1.0FSerial.print(view.diameters[i]);
- additionally:
particles
"view" provides.getLevel()
- ISO classification of air cleanliness. It is not implemented as array - it is a function (a method)Serial.print(view.getLevel(i));
Which one is better? It doesn't matter - code size, memory usage and resulting code is exactly the same using both approaches.
Common pattern in C++ is "initialization in constructor". Unfortunately Arduino breaks that rule.
There is a code from: hardware\arduino\avr\cores\arduino\main.cpp modified for simplicity
// global variables constructors are executed before main()
int main(void) {
init();
initVariant();
setup(); // our setup() procedure
for (;;) {
loop(); // our loop() procedure
}
return 0;
}
Lets imagine:
- If there would be is a global variable
pms
of typePms
. - It would be a good place to initialize serial communication
pms.begin()
withinpms
constructor - Global variables constructors are executed before main()
- After that Arduino initializes all the hardware
- And than our
setup()
is executed.
Our serial connection started in step 3) is destroyed during Arduino initialization in step 4.
There are at least two possible solutions:
By the way: if you are not sure if everything was properly initialized - execute begin()
manually and check the result.
- examples\p01basic\p01basic.ino
- Create static variable of type
Pms
, do nothing in constructor - Initialize it during
setup()
: callpms.begin()
- Use it: call
pms.
methods
PmsAltSerial pmsSerial;
pmsx::Pms pms(&pmsSerial);
void setup(void) {
if (!pms.begin()) {
- Edit pmsConfig.h file, uncomment line
#define PMS_DYNAMIC
- examples\p03cppStyle\p03cppStyle.ino
- Create static variable of type
*Pms
(reference toPms
) - Do nothing prior to main()
- During
setup()
create new object of typePms
, assign created object to the reference from previous stepPms()
constructor is executed automaticallyPms()
constructor executesbegin()
- It executes
begin()
of the serial port driver
- Use it: call
pms->
methods
This approach adds some code size - compiler adds dynamic memory management.
PmsAltSerial pmsSerial;
pmsx::Pms* pms = nullptr;
void setup(void) {
pms = new pmsx::Pms(&pmsSerial);
if (!pms->initialized()) {
C/Arduino way using begin()
is closer to Arduino programming style.
In my opinion: C++ way is closer to modern programming style.
particles
view provides support for ISO 14644-1 classification of air cleanliness levels.
Please refer to p03cppStyle.ino
The code (loop()
function only):
void loop(void) {
static auto lastRead = millis();
pmsx::PmsData data;
auto status = pms->read(data);
switch (status) {
case pmsx::PmsStatus::OK: {
Serial.println("_________________");
const auto newRead = millis();
Serial.print("Wait time ");
Serial.println(newRead - lastRead);
lastRead = newRead;
auto view = data.particles;
for (auto i = decltype(view.SIZE){0}; i < view.getSize(); ++i) {
Serial.print(view.getValue(i));
Serial.print("\t");
Serial.print(view.getName(i));
Serial.print(" [");
Serial.print(view.getMetric(i));
Serial.print("] ");
Serial.print(" Level: ");
Serial.print(view.getLevel(i));
Serial.print(" | diameter: ");
Serial.print(view.getDiameter(i));
Serial.println();
}
break;
}
case pmsx::PmsStatus::NO_DATA:
break;
default:
Serial.print("!!! Pms error: ");
Serial.println(status.getErrorMsg());
}}
and the example of the result:
_________________
Wait time 906
1875 Particles > 0.3 micron [/0.1L] Level: 8.27 | diameter: 0.30
505 Particles > 0.5 micron [/0.1L] Level: 8.16 | diameter: 0.50
62 Particles > 1.0 micron [/0.1L] Level: 7.87 | diameter: 1.00
7 Particles > 2.5 micron [/0.1L] Level: 7.75 | diameter: 2.50
1 Particles > 5.0 micron [/0.1L] Level: 7.53 | diameter: 5.00
0 Particles > 10. micron [/0.1L] Level: 0.00 | diameter: 10.00
pms5003 API description is available as a separate document.
Serial interface is not managed by Pms
. You can suspend data transfer, enter sleep mode, even replace serial port. Just remember to execute pms.begin()
to reinitialize the connection.
pms5003
library is designed to avoid namespace pollution. All classes are located in the namespace pmsx
.
Examples use the fully qualified names like pmsx::Pms pms(&pmsSerial);
To reduce typing it is OK to add using namespace pmsx;
at the beginning and not to type pmsx:: anymore as in examples\p04usingPmsx\p04usingPmsx.ino
It does not change resulting code size.