dart_periphery는 GPIO, I2C, SPI, PWM, LED, ADC, MMIO 및 시리얼 통신을 포함한 Linux 주변기기 I/O 인터페이스에 저수준 액세스를 제공하는 Dart 라이브러리입니다. c-periphery C 라이브러리의 Dart 버전으로, Linux 기반 시스템에서 직접 하드웨어 상호작용을 가능하게 합니다. IoT 및 임베디드 응용 프로그램을 위한 것으로, Dart 코드에서 물리적 장치를 프로그래밍 방식으로 제어하고 모니터링할 수 있게 해줍니다. 최소한의 추상화로 실시간 하드웨어 인터페이싱이 필요한 프로젝트에 이상적입니다.
dart_periphery is a Dart port of the native c-periphery library (v2.5.0)
for Linux Peripheral I/O (GPIO, LED, PWM, SPI, I2C, MMIO and Serial peripheral I/O). This package
is designed for System on Chips (SoCs) such as Raspberry Pi, NanoPi, Banana Pi, and others.
What is c-periphery?
Abstract from the project web site:
c-periphery is a small C library for
GPIO,
LED,
PWM,
SPI,
I2C,
MMIO (Memory Mapped I/O)
Serial peripheral I/O
interface access in userspace Linux. c-periphery simplifies and consolidates the native Linux APIs to these interfaces. c-periphery is useful in embedded Linux environments (including Raspberry Pi, BeagleBone, etc. platforms) for interfacing with external peripherals. c-periphery is re-entrant, has no dependencies outside the standard C library and Linux, compiles into a static library for easy integration with other projects, and is MIT licensed
dart_periphery binds the c-periphery library with the help of the dart:ffi mechanism.
Nevertheless, dart_periphery tries to be close as possible to the original library.
See the following documentation. Thanks to Vanya Sergeev for his great job!
🤔 Why c-periphery?
The number of GPIO libraries/interfaces is shrinking:
import'package:dart_periphery/dart_periphery.dart';
/// https://wiki.seeedstudio.com/Grove-Barometer_Sensor-BME280//// Grove - Temp&Humi&Barometer Sensor (BME280) is a breakout board for Bosch BMP280 high-precision,/// low-power combined humidity, pressure, and temperature sensor.voidmain() {
// Select the right I2C bus number /dev/i2c-?// 1 for Raspberry Pi, 0 for NanoPi (Armbian), 2 Banana Pi (Armbian)var i2c = I2C(1);
try {
print('I2C info:' + i2c.getI2Cinfo());
var bme280 = BME280(i2c);
var r = bme280.getValues();
print('Temperature [°] ${r.temperature.toStringAsFixed(1)}');
print('Humidity [%] ${r.humidity.toStringAsFixed(1)}');
print('Pressure [hPa] ${r.pressure.toStringAsFixed(1)}');
} finally {
i2c.dispose();
}
}
import'package:dart_periphery/dart_periphery.dart';
/// Grove - Temp&Humi Sensor(SHT31) is a highly reliable, accurate,/// quick response and integrated temperature & humidity sensor.voidmain() {
// Select the right I2C bus number /dev/i2c-?// 1 for Raspberry Pi, 0 for NanoPi (Armbian), 2 Banana Pi (Armbian)var i2c = I2C(1);
try {
var sht31 = SHT31(i2c);
print(sht31.getStatus());
print('Serial number ${sht31.getSerialNumber()}');
print('Sensor heater active: ${sht31.isHeaterOn()}');
var r = sht31.getValues();
print('SHT31 [t°] ${r.temperature.toStringAsFixed(2)}');
print('SHT31 [%°] ${r.humidity.toStringAsFixed(2)}');
} finally {
i2c.dispose();
}
}
SPI
import'package:dart_periphery/dart_periphery.dart';
voidmain() {
var spi = SPI(0, 0, SPImode.mode0, 1000000);
try {
print('SPI info:' + spi.getSPIinfo());
var bme280 = BME280.spi(spi);
var r = bme280.getValues();
print('Temperature [°] ${r.temperature.toStringAsFixed(1)}');
print('Humidity [%] ${r.humidity.toStringAsFixed(1)}');
print('Pressure [hPa] ${r.pressure.toStringAsFixed(1)}');
} finally {
spi.dispose();
}
}
Serial
import'package:dart_periphery/dart_periphery.dart';
import'dart:io';
////// [COZIR CO2 Sensor](https://co2meters.com/Documentation/Manuals/Manual_GC_0024_0025_0026_Revised8.pdf)///voidmain() {
print('Serial test - COZIR CO2 Sensor');
var s = Serial('/dev/serial0', Baudrate.b9600);
try {
print('Serial interface info: ' + s.getSerialInfo());
// Return firmware version and sensor serial number - two lines
s.writeString('Y\r\n');
var event = s.read(256, 1000);
print(event.toString());
// Request temperature, humidity and CO2 level.
s.writeString('M 4164\r\n');
// Select polling mode
s.writeString('K 2\r\n');
// print any response
event = s.read(256, 1000);
print('Response ${event.toString()}');
sleep(Duration(seconds: 1));
for (var i = 0; i < 5; ++i) {
s.writeString('Q\r\n');
event = s.read(256, 1000);
print(event.toString());
sleep(Duration(seconds: 5));
}
} finally {
s.dispose();
}
}
Led
import'package:dart_periphery/dart_periphery.dart';
import'dart:io';
voidmain() {
/// Nano Pi power led - see 'ls /sys/class/leds/'var led = Led('nanopi:red:pwr');
try {
print('Led handle: ${led.getLedInfo()}');
print('Led name: ${led.getLedName()}');
print('Led brightness: ${led.getBrightness()}');
print('Led maximum brightness: ${led.getMaxBrightness()}');
var inverse = !led.read();
print('Original led status: ${(!inverse)}');
print('Toggle led');
led.write(inverse);
sleep(Duration(seconds: 5));
inverse = !inverse;
print('Toggle led');
led.write(inverse);
sleep(Duration(seconds: 5));
print('Toggle led');
inverse = !inverse;
led.write(inverse);
sleep(Duration(seconds: 5));
print('Toggle led');
led.write(!inverse);
} finally {
led.dispose();
}
}
PWM
Ensure that PWM is correctly enabled. e.g. see the following documentation for the Raspberry Pi.
Important hint:dart_periphery includes an automatic mechanism to load the correct library.
The additional methods described here can be used to override this default mechanism if needed.
But be aware, any of these methods to disable or change the behaviour the auto detection must be
called before any dart_periphery interface is used!
/// Sets the tmp directory for the extraction of the libperiphery.so file.voidsetTempDirectory(String tmpDir)
/// Allows to load an existing libperiphery.so file from tmp directory. voidreuseTmpFileLibrary(bool reuse)
/// loads the shared library /// export LD_LIBRARY_PATH=/usr/local/lib:$LD_LIBRARY_PATHuseSharedLibrary();
If this method is called, dart_periphery loads the shared library. For this case c-periphery
must be installed as a shared library. See the section Shared Library for details.
To load a custom library call following method
voidsetCustomLibrary(String absolutePath)
This method can also be helpful for a currently not supported platform.
If you want to load the library from the current directory call
Starting from version 0.9.7, the default library handling mechanism creates a temporary library
file, named in the format e.g. pid_1456_libperiphery_arm.so. The unique process ID for each isolate
prevents repeated creation of the temporary library, avoiding crashes caused by overwriting an
actively used library.
This subproject bases on
flutter-pi and implements a simple
Dart isolate/stream architecture designed to transfer sensor data from an isolate to the Flutter UI:
Isolate interface: This consists of the steps InitTask, MainTask, and ExitTask, along with a
limited back channel for controlling the Dart isolate. This setup is typically used for sensor
measurements:
InitTask: Initializes the sensor.
MainTask: Collects sensor data and passes it to a stream.
ExitTask: Disposes of the sensor.
Listening Mode: Supports user-defined handling for isolate events.
This variant remains on standby for data; once data is processed, the result is passed to the stream
and subsequently to the Flutter UI. This model is used for actuator control, such as operating a LED.
Support for Multiple Streams: Enables handling of multiple data streams simultaneously.
This project is currently still beta and development is ongoing.
💧 flutter_sensor_tester
This project builds upon the flutter_pi_sensor_tester by introducing a client/server architecture, enhancing its functionality for distributed applications.
Currently in its alpha stage, the project is scheduled for release in March 2025.
³ Raspberry Pi OS (64-bit), NanoPi Neo2 with a Allwinner H5, Quad-core 64-bit CPU
⁴ Fails for NanoPi, NanoPi Neo2 and Banana Pi on Armbian- same behavior like the original
c-periphery test program. This is a point of deeper investigations
Code review - this is my first public Dart project. I am a Java developer and probably I tend
to solve problems rather in the Java than in the Dart way.
