Difference between revisions of "BakeBit - Light Sensor/zh"
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|SIG || 信号 | |SIG || 信号 | ||
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− | ==硬件连接== | + | == 示例程序:Smart Lighting == |
− | + | ||
+ | 利用亮度传感器,聪明地控制灯光(灯用LED Bar来模拟),环境越暗就让灯越亮,环境亮度足够时,就将灯变暗或者熄灭。 | ||
+ | 本示例需要配合[[BakeBit - LED Bar]]使用。 | ||
+ | |||
+ | === 硬件连接 === | ||
+ | 简单的将[[BakeBit - LED Bar]]模块插入 D3 接口,将[[BakeBit - Light Sensor]]插入 A0 接口,如下面这样: | ||
+ | |||
+ | ::{| class="wikitable" | ||
+ | |- | ||
+ | |[[File:Smart Lighting-1.jpg|frameless|300px]] || [[File:Smart Lighting-2.jpg |frameless|300px]] | ||
+ | |- | ||
+ | |} | ||
+ | |||
+ | === 示例源代码 === | ||
+ | |||
+ | <syntaxhighlight lang="python"> | ||
+ | import time | ||
+ | import bakebit | ||
+ | |||
+ | # Connect the BakeBit Light Sensor to analog port A0 | ||
+ | # SIG,NC,VCC,GND | ||
+ | light_sensor = 0 | ||
+ | |||
+ | # Connect the BakeBit LED Bar to digital port D3 | ||
+ | # DI,DCKI,VCC,GND | ||
+ | ledbar = 3 | ||
+ | |||
+ | |||
+ | lowThreshold = 500 | ||
+ | highTreshold = 600 | ||
+ | |||
+ | bakebit.pinMode(light_sensor,"INPUT") | ||
+ | bakebit.pinMode(ledbar,"OUTPUT") | ||
+ | time.sleep(.2) | ||
+ | bakebit.bakeBitLedBar_Init(ledbar, 0, 5) | ||
+ | time.sleep(.5) | ||
+ | old_color = 0 | ||
+ | |||
+ | while True: | ||
+ | try: | ||
+ | light_count = 0 | ||
+ | |||
+ | # Get sensor value | ||
+ | sensor_value = bakebit.analogRead(light_sensor) | ||
+ | if sensor_value > highTreshold: | ||
+ | f=(1023-highTreshold)/4 | ||
+ | light_count = (sensor_value-highTreshold)/f+1 | ||
+ | |||
+ | # turn on ledbar | ||
+ | color16bit = bakebit.Green | ||
+ | if light_count > 1: | ||
+ | color16bit = color16bit | (bakebit.Green << 3) | ||
+ | if light_count > 2: | ||
+ | color16bit = color16bit | (bakebit.Green << 6) | ||
+ | if light_count > 3: | ||
+ | color16bit = color16bit | (bakebit.Green << 9) | ||
+ | if light_count > 4: | ||
+ | color16bit = 0 | ||
+ | color16bit = color16bit | bakebit.Blue | ||
+ | color16bit = color16bit | (bakebit.Blue << 3) | ||
+ | color16bit = color16bit | (bakebit.Blue << 6) | ||
+ | color16bit = color16bit | (bakebit.Blue << 9) | ||
+ | color16bit = color16bit | (bakebit.Blue << 12) | ||
+ | |||
+ | if color16bit != old_color: | ||
+ | old_color = color16bit | ||
+ | lowBits = color16bit & 255 | ||
+ | highBits = (color16bit & (255 << 8)) >> 8 | ||
+ | bakebit.bakeBitLedBar_Show(ledbar, highBits, lowBits) | ||
+ | |||
+ | elif sensor_value < lowThreshold: | ||
+ | # turn off ledbar | ||
+ | bakebit.bakeBitLedBar_Show(ledbar, 0, 0) | ||
+ | |||
+ | print("sensor_value = %d light_count =%d" %(sensor_value, light_count)) | ||
+ | time.sleep(.5) | ||
+ | |||
+ | except KeyboardInterrupt: | ||
+ | bakebit.bakeBitLedBar_Release(ledbar) | ||
+ | time.sleep(.2) | ||
+ | break | ||
+ | except IOError: | ||
+ | print ("Error") | ||
+ | |||
+ | </syntaxhighlight> | ||
+ | [https://github.com/friendlyarm/BakeBit/blob/master/Software/Python/bakebit_prj_SmartLighting.py Github] | ||
+ | |||
+ | |||
+ | === 运行示例 === | ||
+ | |||
+ | 假设你已经参考[http://wiki.friendlyarm.com/bakebit bakebit教程]安装了BakeBit源代码,<br /> | ||
+ | 要运行示例程序,可以在开发板上进入 BakeBit/Software/Python目录,运行bakebit_prj_SmartLighting.py: | ||
+ | <syntaxhighlight lang="bash"> | ||
+ | cd ~/BakeBit/Software/Python | ||
+ | sudo python bakebit_prj_SmartLighting.py | ||
+ | </syntaxhighlight> | ||
+ | |||
+ | === 运行结果 === | ||
+ | |||
+ | 测试时可用物品盖住光敏电阻模拟环境变暗,或者用手机电筒照射模拟环境变亮,然后观察LED Bar的变化。<br /> | ||
+ | LED Bar上被点亮的LED个数由当前环境的光线决定,越暗,被点亮的就最多。 | ||
− | |||
− | |||
==相关资料== | ==相关资料== | ||
*[Schematic]([http://wiki.friendlyarm.com/wiki/images/e/e8/06-SCHEMATIC_Light_Sensor.pdf BakeBit - Light Sensor.pdf]) | *[Schematic]([http://wiki.friendlyarm.com/wiki/images/e/e8/06-SCHEMATIC_Light_Sensor.pdf BakeBit - Light Sensor.pdf]) | ||
+ | *[BakeBit Github项目](https://github.com/friendlyarm/BakeBit) | ||
+ | *[BakeBit Starter Kit手册](http://wiki.friendlyarm.com/bakebit/bakebit_starter_kit_manual_cn.pdf) |
Latest revision as of 09:03, 28 November 2016
1 介绍
- BakeBit - Light Sensor是一个光敏电阻模块,主要器件是一个光敏电阻。光敏电阻的制作材料具有在特定波长的光照射下,其阻值迅速减小的特性。
- 这是由于光照产生的载流子都参与导电,在外加电场的作用下作漂移运动,电子奔向电源的正极,空穴奔向电源的负极,从而使光敏电阻器的阻值迅速下降。在电源激励下,输出端分压减小。
2 特性
- 使用标准的2.0mm 4 Pin BakeBit接口
- PCB尺寸(mm):20x24
- 模拟信号输出
- 引脚说明:
名称 | 描述 |
GND | 地 |
5V | 电源5V |
NC | 空 |
SIG | 信号 |
3 示例程序:Smart Lighting
利用亮度传感器,聪明地控制灯光(灯用LED Bar来模拟),环境越暗就让灯越亮,环境亮度足够时,就将灯变暗或者熄灭。 本示例需要配合BakeBit - LED Bar使用。
3.1 硬件连接
简单的将BakeBit - LED Bar模块插入 D3 接口,将BakeBit - Light Sensor插入 A0 接口,如下面这样:
3.2 示例源代码
import time import bakebit # Connect the BakeBit Light Sensor to analog port A0 # SIG,NC,VCC,GND light_sensor = 0 # Connect the BakeBit LED Bar to digital port D3 # DI,DCKI,VCC,GND ledbar = 3 lowThreshold = 500 highTreshold = 600 bakebit.pinMode(light_sensor,"INPUT") bakebit.pinMode(ledbar,"OUTPUT") time.sleep(.2) bakebit.bakeBitLedBar_Init(ledbar, 0, 5) time.sleep(.5) old_color = 0 while True: try: light_count = 0 # Get sensor value sensor_value = bakebit.analogRead(light_sensor) if sensor_value > highTreshold: f=(1023-highTreshold)/4 light_count = (sensor_value-highTreshold)/f+1 # turn on ledbar color16bit = bakebit.Green if light_count > 1: color16bit = color16bit | (bakebit.Green << 3) if light_count > 2: color16bit = color16bit | (bakebit.Green << 6) if light_count > 3: color16bit = color16bit | (bakebit.Green << 9) if light_count > 4: color16bit = 0 color16bit = color16bit | bakebit.Blue color16bit = color16bit | (bakebit.Blue << 3) color16bit = color16bit | (bakebit.Blue << 6) color16bit = color16bit | (bakebit.Blue << 9) color16bit = color16bit | (bakebit.Blue << 12) if color16bit != old_color: old_color = color16bit lowBits = color16bit & 255 highBits = (color16bit & (255 << 8)) >> 8 bakebit.bakeBitLedBar_Show(ledbar, highBits, lowBits) elif sensor_value < lowThreshold: # turn off ledbar bakebit.bakeBitLedBar_Show(ledbar, 0, 0) print("sensor_value = %d light_count =%d" %(sensor_value, light_count)) time.sleep(.5) except KeyboardInterrupt: bakebit.bakeBitLedBar_Release(ledbar) time.sleep(.2) break except IOError: print ("Error")
3.3 运行示例
假设你已经参考bakebit教程安装了BakeBit源代码,
要运行示例程序,可以在开发板上进入 BakeBit/Software/Python目录,运行bakebit_prj_SmartLighting.py:
cd ~/BakeBit/Software/Python sudo python bakebit_prj_SmartLighting.py
3.4 运行结果
测试时可用物品盖住光敏电阻模拟环境变暗,或者用手机电筒照射模拟环境变亮,然后观察LED Bar的变化。
LED Bar上被点亮的LED个数由当前环境的光线决定,越暗,被点亮的就最多。
4 相关资料
- [Schematic](BakeBit - Light Sensor.pdf)
- [BakeBit Github项目](https://github.com/friendlyarm/BakeBit)
- [BakeBit Starter Kit手册](http://wiki.friendlyarm.com/bakebit/bakebit_starter_kit_manual_cn.pdf)