Grove Pi’s python API

買GrovePi,主要的原因就是他的API統一了許多複雜的控制,只要學會這13個指令,就可以控制全部的Grove Sensor, 詳細的寫法要開啟 grovepi.py 來看.

API:應用程式介面,Application Programming Interface，簡稱：API），又稱為應用編程介面，就是軟體系統不同組成部分銜接的約定。由於近年來軟體的規模日益龐大，常常需要把複雜的系統劃分成小的組成部分，編程介面的設計十分重要。程式設計的實踐中，編程介面的設計首先要使軟體系統的職責得到合理劃分。良好的介面設計可以降低系統各部分的相互依賴，提高組成單元的內聚性，降低組成單元間的耦合程度，從而提高系統的維護性和擴充功能性。

現成的API可以簡少學習上的困難.以下是將Grove的API資訊轉貼在這裡.

The python library (Available at github) for grove pi has three types of functions:

1. Basic Arduino Functions => Grove的核心是Arduino嗎?
   • digitalRead
   • digitalWrite
   • pinMode
   • analogRead
   • analogWrite
2. Grove Specific Functions
   • temp
   • ultrasonicRead
   • acc_xyz
   • rtc_getTime
   • dht
3. Private Functions for Communication
   • write_i2c_block
   • read_i2c_block
   • read_i2c_byte

 

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Basic Arduino Functions

• digitalRead(pin)

Reads the value from a specified digital pin, either HIGH or LOW.

Parameter:    

pin: The Pin number

Return: 1 for HIGH and 0 for LOW

• digitalWrite(pin,value)

Write a HIGH or a LOW value to a digital pin.

Parameter:

pin: The Pin number

value: 1 for HIGH and 0 for LOW

Return: 1 on success

• pinMode(pin,mode)

Configures the specified pin to behave either as an input or an output.

Parameter:

pin: the number of the pin whose mode you wish to set

mode: INPUT, OUTPUT

Return: 1 on success

• analogRead(pin):

Reads the value from the specified analog pin.

Parameters

pin: the number of the analog input pin to read from (0,1 and 2)

Returns: 0 to 1023

• analogWrite(pin,value):

Writes an analog value (PWM wave) to a pin

Parameters

pin: the pin to write to.

value: the duty cycle: between 0 (always off) and 255 (always on).

Return: 1 on success

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Grove Specific functions

• temp(pin)

Read the temperature from the analog Grove Temperature Sensor http://www.seeedstudio.com/depot/Grove-Temperature-Sensor-p-774.html

Parameter:

pin: the number of the analog input pin to read from (0,1 and 2)

Return: temp in float

• ultrasonicRead(pin)

Read the distance reading from the Grove Ultasonic ranger http://www.seeedstudio.com/depot/Grove-Ultrasonic-Ranger-p-960.html

Parameter:

pin: pin on which the Ultrasonic ranger is connected

Return: distance in cm

• acc_xyz()

read the x,y,z value from the accelerometer http://www.seeedstudio.com/depot/Grove-3Axis-Digital-Accelerometer15g-p-765.html?cPath=25_26

return: an array of 3 values [x,y,z] -32 to 32 (-1.5g to +1.5g)

• rtc_getTime()

Read the time from Grove RTC http://www.seeedstudio.com/depot/Grove-RTC-p-758.html?cPath=25_30

Return: 8 byte array [hour,min,sec,month,dayOfMonth,year,dayOfMonth,dayOfWeek] or junk value if RTC not connected

• dht (pin,module_type)

Parameter:

pin: pin on which the DHT  sensor  is connected

module_type:

0-      DHT11

1-      DHT22

2-      DHT21

3-      AM2301

Return:  array of 2 floats [temp,humidity]

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Private functions (should not be used directly)

• write_i2c_block (address,block)

Write a block of data to address using I2C interface

Parameter:

address: address of the I2C device (0x04 GrovePi)

block: block of data in bytes to be sent

Return: positive value on success, -1 on failure

• read_i2c_block (address)

Read a block of data from address using I2C interface

Parameter:

address: address of the I2C device (0x04 GrovePi)

Return: block of data read on success, -1 on failure

• read_i2c_byte (address)

Read a byte of data from address using I2C interface

Parameter:

address: address of the I2C device (0x04 GrovePi)

Return: byte of data read on success, -1 on failure