Edison上程序开发——Python API 一览 DF创客社区

孙毅发表于 2015-10-30 23:35:29

Edison上程序开发——Python API 一览

本帖最后由孙毅于 2015-10-31 00:35 编辑

前面我们学了如何使用Python来编程，也做了几个例子了。这次教程，我们一块看下Edison Python编程中所有的API。
不需要背过，至少我们也得混个脸熟啊，这样在需要的时候，我们得知道去哪里找他们啊。
下面基本上就是Edison提供给我们所有的Python API了。恕我懒惰，没有翻译成汉语啊，不过这样可以培养大家看英文文档的能力啊。嘻嘻嘻。
有任何问题，直接回复，跟大家一块看一下啊。

总的来说，一共7类API，就涵盖了几乎所有的功能了：
Aio
I2c
Gpio
Pwm
Spi
Uart
Common
来下面我们一个类一个类的帮大家列出来，以下部分可粗略过一下，用到的时候，再来查询好了:p

Aio
class mraa.Aio(pin)
API to Analog IO.
This file defines the aio interface for libmraa
   getBit() → int
            Gets the bit value mraa is shifting the analog read to.
            bit value mraa is set return from the read function

   read() → int
            Read a value from the AIO pin. By default mraa will shift the raw value up or down to a 10 bit value.
            The current input voltage. By default, a 10bit value

   readFloat() → float
            Read a value from the AIO pin and return it as a normalized float.
            The current input voltage as a normalized float (0.0f-1.0f)

   setBit(int bits) → mraa::Result
            Set the bit value which mraa will shift the raw reading from the ADC to. I.e. 10bits
            bits: the bits the return from read should be i.e 10

I2c
class mraa.I2c(bus, raw=False)
API to Inter-Integrated Circuit.
An I2c object represents an i2c master and can talk multiple i2c slaves by selecting the correct addressIt is considered best practice to make sure the address is correct before doing any calls on i2c, in case another application or even thread changed the addres on that bus. Multiple instances of the same bus can exist.

   address( uint8_t address) → mraa::Result
            Set the slave to talk to, typically called before every read/write operation
            address: Communicate to the i2c slave on this address

   frequency( mraa::I2cMode mode) → mraa::Result
            Sets the i2c Frequency for communication. Your board may not support the set frequency. Anyone can change this at any time and this will affect every slave on the bus
            mode: Frequency to set the bus to

   read( uint8_t * data) → int
            Read length bytes from the bus into *data pointer
            data: Data to read into
            length: Size of read in bytes to make
            length of read, should match length

   readByte() → uint8_t
            Read exactly one byte from the bus
            char read from the bus

   readBytesReg( uint8_t reg, uint8_t * data) → int
            Read length bytes from the bus into *data pointer starting from an i2c register
            reg: Register to read from
            data: pointer to the byte array to read data in to
            length: max number of bytes to read
            length passed to the function or -1

   readReg( uint8_t reg) → uint8_t
            Read byte from an i2c register
            reg: Register to read from
            char read from register

   readWordReg( uint8_t reg) → uint16_t
            Read word from an i2c register
            reg: Register to read from
            char read from register

   write( uint8_t const * data) → mraa::Result
            Write length bytes to the bus, the first byte in the array is the command/register to write
            data: Buffer to send on the bus, first byte is i2c command
            length: Size of buffer to send

   writeByte( uint8_t data) → mraa::Result
            Write a byte on the bus
            data: The byte to send on the bus

   writeReg( uint8_t reg, uint8_t data) → mraa::Result
            Write a byte to an i2c register
            reg: Register to write to
            data: Value to write to register

   writeWordReg( uint8_t reg, uint16_t data) → mraa::Result
            Write a word to an i2c register
            reg: Register to write to
            data: Value to write to register

Gpio
class mraa.Gpio(pin, owner=True, raw=False)
API to General Purpose IO.
This file defines the gpio interface for libmraa

   dir( mraa:: Dir dir) → mraa::Result
            Change Gpio direction
            dir: The direction to change the gpio into

   edge( mraa::Edge mode) → mraa::Result
            Set the edge mode for ISR
            mode: The edge mode to set

   getPin( bool raw=False) → int
   getPin() -> int
            Get pin number of Gpio. If raw param is True will return the number as used within sysfs. Invalid will return -1.
            raw: (optional) get the raw gpio number.

   isr( mraa::Edge mode, PyObject * pyfunc, PyObject * args) → mraa::Result
            Sets a callback to be called when pin value changes
            mode: The edge mode to set
            fptr: Function pointer to function to be called when interupt is triggered
            args: Arguments passed to the interrupt handler (fptr)

   isrExit() → mraa::Result
            Exits callback - this call will not kill the isr thread immediatly but only when it is out of it’s critical section

   mode( mraa::Mode mode) → mraa::Result
            Change Gpio mode
            mode: The mode to change the gpio into

   read() → int
            Read value from Gpio

   useMmap( bool enable) → mraa::Result
            Enable use of mmap i/o if available.
            enable: true to use mmap

   write( int value) → mraa::Result
            Write value to Gpio
            value: Value to write to Gpio

Pwm
class mraa.Pwm(pin, owner=True, chipid=-1)
API to Pulse Width Modulation.
This file defines the PWM interface for libmraa

   config_ms( int period, float duty) → mraa::Result
            Set the period and duty of a PWM object.
            period: represented in ms.
            duty: represnted in ms as float.

   config_percent( int period, float duty) → mraa::Result
            Set the period and duty (percent) of a PWM object.
            period: as represented in ms.
            duty: percentage i.e. 50% = 0.5f

   enable( bool enable) → mraa::Result
            Set the enable status of the PWM pin. None zero will assume on with output being driven and 0 will disable the output
            enable: enable status of pin

   max_period() → int
            Get the maximum pwm period in us
            max pwm in us

   min_period() → int
            Get the minimum pwm period in us
            min pwm in us

   period( float period) → mraa::Result
            Set the PWM period as seconds represented in a float
            period: Period represented as a float in seconds

   period_ms( int ms) → mraa::Result
            Set period, milliseconds
            ms: milliseconds for period

   period_us( int us) → mraa::Result
            Set period, microseconds
            us: microseconds as period

   pulsewidth( float seconds) → mraa::Result
            Set pulsewidth, As represnted by seconds in a (float)
            seconds: The duration of a pulse

   pulsewidth_ms( int ms) → mraa::Result
            Set pulsewidth, milliseconds

   pulsewidth_us( int us) → mraa::Result
            The pulsewidth, microseconds
            us: microseconds for pulsewidth

   read() → float
            Read the ouput duty-cycle percentage, as a float
            A floating-point value representing percentage of output. The value should lie between 0.0f (representing on 0%) and 1.0f Values above or below this range will be set at either 0.0f or 1.0f

   write( float percentage) → mraa::Result
            Set the output duty-cycle percentage, as a float
            percentage: A floating-point value representing percentage of output. The value should lie between 0.0f (representing on 0%) and 1.0f Values above or below this range will be set at either 0.0f or 1.0f

Spi
class mraa.Spi(bus)
API to Serial Peripheral Interface.
This file defines the SPI interface for libmraa

   bitPerWord( unsigned int bits) → mraa::Result
            Set bits per mode on transaction, default is 8
            bits: bits per word

   frequency( int hz) → mraa::Result
            Set the SPI device operating clock frequency
            hz: the frequency to set in hz

   lsbmode( bool lsb) → mraa::Result
            Change the SPI lsb mode
            lsb: bool
            lsb: Use least significant bit transmission - 0 for msbi

   mode( mraa::Spi_Mode mode) → mraa::Result
            Set the SPI device mode. see spidev0-3
            mode: the mode. See Linux spidev doc

   write( uint8_t * txBuf) → uint8_t *
            Write buffer of bytes to SPI device The pointer return has to be free’d by the caller. It will return a NULL pointer in cases of error
            txBuf: buffer to send
            length: size of buffer to send
            uint8_t* data received on the miso line. Same length as passed in

   writeByte( uint8_t data) → int
            Write single byte to the SPI device
            data: the byte to send
            data received on the miso line or -1 in case of error

   write_word( uint16_t data) → uint16_t
            Write buffer of bytes to SPI device The pointer return has to be free’d by the caller. It will return a NULL pointer in cases of error
            txBuf: buffer to send
            length: size of buffer (in bytes) to send
            uint8_t* data received on the miso line. Same length as passed in

Uart
class mraa.Uart(*args)
API to UART (enabling only)
This file defines the UART interface for libmraa

   dataAvailable( unsigned int millis=0) → bool
            dataAvailable() -> bool
            Check to see if data is available on the device for reading
            millis: number of milliseconds to wait, or 0 to return immediately
            true if there is data available to read, false otherwise

   flush() → mraa::Result
            Flush the outbound data. Blocks until complete.

   getDevicePath() → std::string
            Get string with tty device path within Linux For example. Could point to “/dev/ttyS0”
            char pointer of device path

   read( char * data) → int
            Read bytes from the device into char* buffer
            data: buffer pointer
            length: maximum size of buffer
            numbers of bytes read

   readStr( int length) → std::string
            Read bytes from the device into a String object
            length: to read
            string of data

   setBaudRate( unsigned int baud) → mraa::Result
            Set the baudrate. Takes an int and will attempt to decide what baudrate is to be used on the UART hardware.
            baud: unsigned int of baudrate i.e. 9600

   setFlowcontrol( bool xonxoff, bool rtscts) → mraa::Result
            Set the flowcontrol
            xonxoff: XON/XOFF Software flow control.
            rtscts: RTS/CTS out of band hardware flow control

   setMode( int bytesize, mraa::UartParity parity, int stopbits) → mraa::Result
            Set the transfer mode For example setting the mode to 8N1 would be “dev.setMode(8,UART_PARITY_NONE , 1)”
            bytesize: data bits
            parity: Parity bit setting
            stopbits: stop bits

   setTimeout( int read, int write, int interchar) → mraa::Result
            Set the timeout for read and write operations <= 0 will disable that timeout
            read: read timeout
            write: write timeout
            interchar: inbetween char timeout

   write( char const * data) → int
            Write bytes in String object to a device
            data: buffer pointer
            length: maximum size of buffer
            the number of bytes written, or -1 if an error occurred

   writeStr( std::string data) → int
            Write bytes in String object to a device
            the number of bytes written, or -1 if an error occurred

Common
Python interface to libmraa
   mraa.adcRawBits() → unsigned int
   mraa.adcSupportedBits() → unsigned int
   mraa.getI2cBusCount() → int
   mraa.getI2cBusId(unsigned int i2c_bus) → int
   mraa.getPinCount() → unsigned int
   mraa.getPinName(int pin) → std::string
   mraa.getPlatformName() → std::string
   mraa.getPlatformType() → mraa:: Platform
   mraa.getSubPlatformId(int pin_or_bus_index) → int
   mraa.getSubPlatformIndex(int pin_or_bus_id) → int
   mraa.getVersion() → std::string
   mraa.hasSubPlatform() → bool
   mraa.init() → mraa::Result
   mraa.isSubPlatformId(int pin_or_bus_id) → bool
   mraa.pinModeTest(int pin, mraa:: Pinmodes mode) → bool
   mraa.printError(mraa::Result result)
   mraa.setLogLevel(int level) → mraa::Result
   mraa.setPriority(unsigned int const priority) → int

丄帝De咗臂 发表于 2015-10-31 08:46:13

顶{:5_171:}

大连林海 发表于 2015-10-31 12:59:42

求翻译求翻译

hnyzcj 发表于 2015-10-31 19:47:55

大圣你这样搞好像不地道，搞点例如好不好

孙毅发表于 2015-10-31 20:00:30

大连林海发表于 2015-10-31 12:59
求翻译求翻译

翻译也是然并卵啊。。。。

孙毅发表于 2015-10-31 20:00:53

hnyzcj 发表于 2015-10-31 19:47
大圣你这样搞好像不地道，搞点例如好不好

好说，例子马上就到位！吼吼吼

hnyzcj 发表于 2015-10-31 20:26:43

孙毅发表于 2015-10-31 20:00
好说，例子马上就到位！吼吼吼

感谢大圣

hnyzcj 发表于 2015-10-31 20:27:37

孙毅发表于 2015-10-31 20:00
好说，例子马上就到位！吼吼吼

这对你来说都是小孩游戏

大连林海 发表于 2015-10-31 20:29:43

hnyzcj 发表于 2015-10-31 20:27
这对你来说都是小孩游戏

等到花儿都谢了

孙毅发表于 2015-10-31 23:54:12

大连林海发表于 2015-10-31 20:29
等到花儿都谢了

去看吧，不知道花儿明天是否依然会开{:5_168:}

孙毅发表于 2015-10-31 23:54:48

hnyzcj 发表于 2015-10-31 20:27
这对你来说都是小孩游戏

别整没用的！赶紧学起来！

大连林海 发表于 2015-11-1 08:56:48

孙毅发表于 2015-10-31 23:54
去看吧，不知道花儿明天是否依然会开

你这不错哦

大连林海 发表于 2015-11-1 08:57:12

孙毅发表于 2015-10-31 23:54
别整没用的！赶紧学起来！

你就笑话我们不过也是鞭策

hublot 发表于 2017-5-24 10:22:00

大神好，请问这篇英文文档的源地址在哪呀？

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Edison上程序开发——Python API 一览