摘要：表示磁場(chǎng)強(qiáng)度的值浮動(dòng)軸的。操縱桿操縱事件描述操縱桿事件的元組。在發(fā)生事件之前阻止執(zhí)行，然后返回一個(gè)表示發(fā)生的事件的。相關(guān)資料博客原文原文樹莓派的一個(gè)入門項(xiàng)目來自官方的簡(jiǎn)介

從官方給的 api 文檔中硬翻的...

這個(gè)函數(shù)可以設(shè)置 led 的旋轉(zhuǎn)角度

示例:

#!/usr/bin/python
import sys
import time
from sense_hat import SenseHat

X = (255, 0, 0)
O = (255, 255, 255)

question_mark = [
    O, O, O, X, X, O, O, O,
    O, O, X, O, O, X, O, O,
    O, O, O, O, O, X, O, O,
    O, O, O, O, X, O, O, O,
    O, O, O, X, O, O, O, O,
    O, O, O, X, O, O, O, O,
    O, O, O, O, O, O, O, O,
    O, O, O, X, O, O, O, O
]

sense = SenseHat()

sense.set_pixels(question_mark)

sense.set_pixel(0, 0, 255, 0, 0)
sense.set_pixel(0, 7, 0, 255, 0)
sense.set_pixel(7, 0, 0, 0, 255)
sense.set_pixel(7, 7, 255, 0, 255)

def close_light():
    black = [ [0,0,0] ] * 64
    sense.set_pixels(black)

try:
    while True:
        for r in [0, 90, 180, 270]:
            sense.set_rotation(r)
            time.sleep(0.3)
except KeyboardInterrupt:
    close_light()
    print "Good bye"

改變64顆 led 的顯示顏色

示例參考上一個(gè)示例

示例:

#!/usr/bin/python
from sense_hat import SenseHat


X = (255, 0, 0)
O = (0, 0, 0)
question_mark = [
    O, X, O, O, O, O, X, O,
    O, O, X, O, O, X, O, O,
    O, X, X, X, X, X, X, O,
    X, X, O, X, X, O, X, X,
    X, X, X, X, X, X, X, X,
    X, X, X, X, X, X, X, X,
    O, X, O, O, O, O, X, O,
    X, O, O, O, O, O, O, X
]

sense = SenseHat()

sense.set_pixels(question_mark)
out_list = sense.get_pixels()
print out_list

提示:之所以有這個(gè)函數(shù)是因?yàn)閭魅?b>set_pixels的像素值有時(shí)會(huì)發(fā)生變化,sense HAT 是將每個(gè)像素指定為  
8 位數(shù) (0-255) 但是如果傳入 led 的 frameBuffer 中的時(shí)候,顏色的位數(shù)會(huì)轉(zhuǎn)成 RGB565(5位紅色,6位綠色和5位藍(lán)色)  
執(zhí)行轉(zhuǎn)換的時(shí)候可以看到二進(jìn)制轉(zhuǎn)換時(shí)發(fā)生的精度損失
get_pixels 就是顯示像素在緩沖區(qū)內(nèi)結(jié)束時(shí)的值

通過 x-y 坐標(biāo)系來定位像素位置,以 HDMI 接口面向的位置為下

示例:

from sense_hat import SenseHat

sense = SenseHat()

# examples using (x, y, r, g, b)
sense.set_pixel(0, 0, 255, 0, 0)
sense.set_pixel(0, 7, 0, 255, 0)
sense.set_pixel(7, 0, 0, 0, 255)
sense.set_pixel(7, 7, 255, 0, 255)

red = (255, 0, 0)
green = (0, 255, 0)
blue = (0, 0, 255)

# examples using (x, y, pixel)
sense.set_pixel(0, 0, red)
sense.set_pixel(0, 0, green)
sense.set_pixel(0, 0, blue)

同 get_pixels 不過是單體版的

示例:

from sense_hat import SenseHat

sense = SenseHat()
top_left_pixel = sense.get_pixel(0, 0)

加載一個(gè)圖像文件，將其轉(zhuǎn)換為RGB格式，并在LED矩陣上顯示。圖像的大小必須是8×8像素。

示例:

from sense_hat import SenseHat

sense = SenseHat()
sense.load_image("space_invader.png")

from sense_hat import SenseHat

sense = SenseHat()
invader_pixels = sense.load_image("space_invader.png", redraw=False)

示例:

from sense_hat import SenseHat
from time import sleep

sense = SenseHat()

red = (255, 0, 0)

sense.clear()  # no arguments defaults to off
sleep(1)
sense.clear(red)  # passing in an RGB tuple
sleep(1)
sense.clear(255, 255, 255)  # passing in r, g and b values of a colour

就是街頭廣告燈的那種 led 滾屏啦!

示例:

from sense_hat import SenseHat

sense = SenseHat()
sense.show_message("One small step for Pi!", text_colour=[255, 0, 0])

示例:

#!/usr/bin/python
import time
from sense_hat import SenseHat

sense = SenseHat()

letters = "ABCDEFGHIJKLMNOPQRSTUVWSYZ"


for i in letters:
    sense.show_letter(str(i))
    time.sleep(1)

如果覺得亮度有點(diǎn)刺眼的話可以開低亮度模式

import time
from sense_hat import SenseHat

sense = SenseHat()
sense.clear(255, 255, 255)
sense.low_light = True
time.sleep(2)
sense.low_light = False

#!/usr/bin/python
import time
from sense_hat import SenseHat

sense = SenseHat()
sense.clear(255, 127, 0)

sense.set_pixels(question_mark)

print(sense.gamma)
time.sleep(2)

old = sense.gamma
sense.gamma = old[::-1]
print(sense.gamma)
time.sleep(2)


sense.low_light = True
print(sense.gamma)
time.sleep(2)

sense.low_light = False

For advanced users. Most users will just need the low_light Boolean property above. The Sense HAT python API uses 8 bit (0 to 255) colours for R, G, B. When these are written to the Linux frame buffer they"re bit shifted into RGB 5 6 5. The driver then converts them to RGB 5 5 5 before it passes them over to the ATTiny88 AVR for writing to the LEDs.
The gamma property allows you to specify a gamma lookup table for the final 5 bits of colour used. The lookup table is a list of 32 numbers that must be between 0 and 31. The value of the incoming 5 bit colour is used to index the lookup table and the value found at that position is then written to the LEDs.

對(duì)于高級(jí)用戶。大多數(shù)用戶只需要上面的low_light布爾屬性。這個(gè)感覺帽python API使用8位(0到255)的顏色為R,G,b。當(dāng)這些被寫入Linux框架緩沖區(qū)時(shí)，它們被位轉(zhuǎn)換為RGB 5 6 5。然后，驅(qū)動(dòng)程序?qū)⑺鼈冝D(zhuǎn)換為RGB 5 5 5，然后將其傳遞給ATTiny88 AVR以寫入led。
gamma屬性允許您為使用的最后5位顏色指定一個(gè)伽馬查找表。查找表是32個(gè)數(shù)字的列表，它們必須在0到31之間。傳入的5位顏色的值用于索引查找表，然后將該位置上發(fā)現(xiàn)的值寫入led。
---來自有道詞典,因?yàn)闀簳r(shí)不知道用在哪里

示例:

import time
from sense_hat import SenseHat

sense = SenseHat()
sense.clear(255, 127, 0)

print(sense.gamma)
time.sleep(2)

sense.gamma = sense.gamma[::-1]
print(sense.gamma)
time.sleep(2)

sense.low_light = True
print(sense.gamma)
time.sleep(2)

sense.low_light = False

一個(gè)函數(shù)將gamma查找表重置為默認(rèn)值，理想情況下，如果您已經(jīng)對(duì)它進(jìn)行了處理，并希望將它恢復(fù)到默認(rèn)狀態(tài)。
示例:

import time
from sense_hat import SenseHat

sense = SenseHat()
sense.clear(255, 127, 0)
time.sleep(2)
sense.gamma = [0] * 32  # Will turn the LED matrix off
time.sleep(2)
sense.gamma_reset()

示例:

#!/usr/bin/python
from sense_hat import SenseHat

sense = SenseHat()
humidity = sense.get_humidity()
print("Humidity: %s %%rH" % humidity)  #Humidity: 13.8048038483 %rH

# 同樣效果
print(sense.humidity)   #14.9011135101

返回值也是浮點(diǎn)數(shù)
示例:

#!/usr/bin/python
from sense_hat import SenseHat

sense = SenseHat()
temp = sense.get_temperature()
print("Temperature: %s C" % temp)   # Temperature: 33.0 C

# alternatives
print(sense.temp)       # 33.0
print(sense.temperature)    # 33.0

從濕度傳感器獲取當(dāng)前溫度(攝氏度)。
示例:

from sense_hat import SenseHat

sense = SenseHat()
temp = sense.get_temperature_from_humidity()
print("Temperature: %s C" % temp)

從壓力傳感器獲取溫度

from sense_hat import SenseHat

sense = SenseHat()
temp = sense.get_temperature_from_pressure()
print("Temperature: %s C" % temp)

獲取壓力參數(shù)

ps: 1Bar=0.1MPa=1000mba=1000hpa=100*7.5mmhg=75mmhg=1個(gè)大氣壓

示例:

from sense_hat import SenseHat

sense = SenseHat()
pressure = sense.get_pressure()
print("Pressure: %s Millibars" % pressure)  #Pressure: 1024.56738281 Millibars

# 同理
print(sense.pressure)   # 1024.56738281

IMU(inertial measurement unit)傳感器是三個(gè)傳感器的組合，每個(gè)傳感器分別有x、y和z軸。由于這個(gè)原因，它被認(rèn)為是一個(gè)9自由度的傳感器。

陀螺儀(Gyroscope)

加速度計(jì)(Accelerometer)

指南針(Magnetometer)

這個(gè)API允許你在任何組合中使用這些傳感器來測(cè)量方向或多帶帶的傳感器。

支持或禁用陀螺儀、加速度計(jì)和/或磁強(qiáng)計(jì)

示例:

from sense_hat import SenseHat

sense = SenseHat()
sense.set_imu_config(False, True, False)  # 只開啟陀螺儀

獲取當(dāng)前方向弧度,依據(jù)飛行器軸參數(shù)的 pitch, roll 和 yaw.
理解傳說中的roll、yaw、pitch
歐拉角

示例:

from sense_hat import SenseHat

sense = SenseHat()
orientation_rad = sense.get_orientation_radians()
print("p: {pitch}, r: {roll}, y: {yaw}".format(**orientation_rad)) # p: 0.0906969159842, r: -0.218863099813, y: 2.87161874771

# alternatives
print(sense.orientation_radians) # {"yaw": 2.933598041534424, "roll": -0.20759552717208862, "pitch": 0.09733205288648605}

以俯仰、翻滾和偏航的飛機(jī)主軸得到當(dāng)前的方向。

示例:

from sense_hat import SenseHat

sense = SenseHat()
orientation = sense.get_orientation_degrees()
print("p: {pitch}, r: {roll}, y: {yaw}".format(**orientation)) # p: 359.368855623, r: 359.958133745, y: 24.4292643968

作用同get_orientation_degrees

from sense_hat import SenseHat

sense = SenseHat()
orientation = sense.get_orientation()

print(sense.orientation) # {"yaw": 20.334569404489745, "roll": 0.02406978340326997, "pitch": 359.2895215347403}

調(diào)用羅盤時(shí)會(huì)預(yù)先調(diào)用set_imu_config禁止掉重力計(jì)和加速度計(jì)的功能

from sense_hat import SenseHat

sense = SenseHat()
north = sense.get_compass()
print("North: %s" % north) # North: 351.031626941

# alternatives
print(sense.compass) # 351.031626941

獲取原始x、y和z軸的磁強(qiáng)計(jì)數(shù)據(jù)。

from sense_hat import SenseHat

sense = SenseHat()
raw = sense.get_compass_raw()
print("x: {x}, y: {y}, z: {z}".format(**raw)) # x: 3.14855718613, y: 0.269534498453, z: -0.743863344193

# alternatives
print(sense.compass_raw) # {"y": 0.4851621091365814, "x": 5.667402744293213, "z": -1.338953971862793}

調(diào)用set_imu_config來禁用磁強(qiáng)計(jì)和加速計(jì)，然后只從陀螺儀獲取當(dāng)前方向。

from sense_hat import SenseHat

sense = SenseHat()
gyro_only = sense.get_gyroscope()
print("p: {pitch}, r: {roll}, y: {yaw}".format(**gyro_only))

# alternatives
print(sense.gyro) # {"yaw": 0.0604013305118731, "roll": 359.9494321175156, "pitch": 359.9567423509234}
print(sense.gyroscope) # {"yaw": 0.0604013305118731, "roll": 359.9494321175156, "pitch": 359.9567423509234}

獲取原始x、y和z軸的陀螺儀數(shù)據(jù)。

from sense_hat import SenseHat

sense = SenseHat()
raw = sense.get_gyroscope_raw()
print("x: {x}, y: {y}, z: {z}".format(**raw))

# alternatives
print(sense.gyro_raw)
print(sense.gyroscope_raw)

# x: 1.03765261173, y: 2.46352291107, z: 0.185390725732
# {"y": 1.5728815793991089, "x": 0.34309887886047363, "z": 0.2984008193016052}
# {"y": 0.8343454599380493, "x": 0.163504496216774, "z": 0.4767734408378601}

調(diào)用set_imu_config來禁用磁力儀和陀螺儀，然后從加速度計(jì)得到當(dāng)前的方向。

from sense_hat import SenseHat

sense = SenseHat()
accel_only = sense.get_accelerometer()
print("p: {pitch}, r: {roll}, y: {yaw}".format(**accel_only))

# alternatives
print(sense.accel)
print(sense.accelerometer)

# p: 3.76471788135, r: 10.0814548376, y: 0.0
# {"yaw": 4.5454772552392335e-07, "roll": 10.082596332952239, "pitch": 3.7639588765826475}
# {"yaw": 4.5454772552392335e-07, "roll": 10.082596332952239, "pitch": 3.7639588765826475}

獲取原始x、y和z軸加速度計(jì)數(shù)據(jù)。

from sense_hat import SenseHat

sense = SenseHat()
raw = sense.get_accelerometer_raw()
print("x: {x}, y: {y}, z: {z}".format(**raw))

# alternatives
print(sense.accel_raw)
print(sense.accelerometer_raw)

# x: -0.0634367614985, y: 0.172625526786, z: 0.974787354469
# {"y": 0.1738394945859909, "x": -0.06516461074352264, "z": 0.9757621884346008}
# {"y": 0.17286831140518188, "x": -0.06565827876329422, "z": 0.9735689163208008}

描述操縱桿事件的元組。包含三個(gè)命名參數(shù):

時(shí)間戳—事件發(fā)生的時(shí)間，作為秒數(shù)(與內(nèi)置時(shí)間函數(shù)相同的格式)

方向-操縱桿移動(dòng)的方向，作為一個(gè)字符串(“向上”，“向下”，“左”，“右”，“中間”)

動(dòng)作—發(fā)生的動(dòng)作，作為一個(gè)字符串(“按壓”，“釋放”，“持有”)

這個(gè)tuple類型被一些joystick方法使用，要么作為返回類型，要么是參數(shù)的類型。

在發(fā)生joystick事件之前阻止執(zhí)行，然后返回一個(gè)表示發(fā)生的事件的InputEvent。

from sense_hat import SenseHat
from time import sleep

sense = SenseHat()
event = sense.stick.wait_for_event()
print("The joystick was {} {}".format(event.action, event.direction))
sleep(0.1)
event = sense.stick.wait_for_event()
print("The joystick was {} {}".format(event.action, event.direction))

在上面的例子中，如果你將操縱桿簡(jiǎn)單地推到一個(gè)單一的方向，你就會(huì)看到兩個(gè)事件輸出:一個(gè)被壓的動(dòng)作和一個(gè)釋放的動(dòng)作。可選的emptybuffer可以用于在等待新事件之前刷新任何未決事件。試試下面的腳本，看看有什么不同:

from sense_hat import SenseHat
from time import sleep

sense = SenseHat()
event = sense.stick.wait_for_event()
print("The joystick was {} {}".format(event.action, event.direction))
sleep(0.1)
event = sense.stick.wait_for_event(emptybuffer=True)
print("The joystick was {} {}".format(event.action, event.direction))

返回自最后一次調(diào)用get_events或wait_for_event之后發(fā)生的所有事件的InputEvent tuple的列表。

from sense_hat import SenseHat

sense = SenseHat()
while True:
    for event in sense.stick.get_events():
        print("The joystick was {} {}".format(event.action, event.direction))

這些屬性可以被分配一個(gè)函數(shù)，當(dāng)操縱桿按在相關(guān)的方向(或者在direction_any的任何方向上)時(shí)，它就會(huì)被調(diào)用。分配的函數(shù)要么不接受參數(shù)，要么必須接受一個(gè)參數(shù)，該參數(shù)將傳遞給相關(guān)的InputEvent。

from sense_hat import SenseHat, ACTION_PRESSED, ACTION_HELD, ACTION_RELEASED
from signal import pause

x = 3
y = 3
sense = SenseHat()

def clamp(value, min_value=0, max_value=7):
    return min(max_value, max(min_value, value))

def pushed_up(event):
    global y
    if event.action != ACTION_RELEASED:
        y = clamp(y - 1)

def pushed_down(event):
    global y
    if event.action != ACTION_RELEASED:
        y = clamp(y + 1)

def pushed_left(event):
    global x
    if event.action != ACTION_RELEASED:
        x = clamp(x - 1)

def pushed_right(event):
    global x
    if event.action != ACTION_RELEASED:
        x = clamp(x + 1)

def refresh():
    sense.clear()
    sense.set_pixel(x, y, 255, 255, 255)

sense.stick.direction_up = pushed_up
sense.stick.direction_down = pushed_down
sense.stick.direction_left = pushed_left
sense.stick.direction_right = pushed_right
sense.stick.direction_any = refresh
refresh()
pause()

博客原文
api 原文
樹莓派+senseHAT 的一個(gè)入門項(xiàng)目
來自官方的 astro-pi 簡(jiǎn)介