Difference between revisions of "BakeBit - Rotary Angle Sensor/zh"
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== 示例程序(3):LED Bar and Rotary Angle Sensor == | == 示例程序(3):LED Bar and Rotary Angle Sensor == | ||
− | + | 这个示例实现类拟音量调节的效果,用到电位器模块和LED Bar。<br /> | |
该示例是配合[[BakeBit - LED Bar]]来实现的,可参考[[BakeBit - LED Bar]]页面。 | 该示例是配合[[BakeBit - LED Bar]]来实现的,可参考[[BakeBit - LED Bar]]页面。 | ||
Revision as of 09:45, 28 November 2016
Contents
1 介绍
- BakeBit - Rotary Angle Senso是一个旋转角度传感器模块,模块使用了一个旋转电位器。通过改变接入电路部分电阻线的长度来改变接入部分的电阻值,从而改变输出端的分压。
2 特性
- 使用标准的2.0mm 4 Pin BakeBit接口
- 引脚说明:
名称 | 描述 |
GND | 地 |
5V | 电源5V |
NC | 空 |
SIG | 信号 |
3 示例程序(1):LED Fade
这个项目将使用BakeBit - Rotary Angle Sensor模块,来动态调节LED的亮度。
3.1 硬件连接
简单的将 LED 模块插入 D5接口,将 BakeBit - Rotary Angle 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 Rotary Angle Sensor to analog port A0 # SIG,NC,VCC,GND potentiometer = 0 # Connect the LED to digital port D5 # SIG,NC,VCC,GND led = 5 bakebit.pinMode(potentiometer,"INPUT") bakebit.pinMode(led,"OUTPUT") time.sleep(1) # Reference voltage of ADC is 5v adc_ref = 5 # Vcc of the BakeBit interface is normally 5v bakebit_vcc = 5 # Full value of the rotary angle is 300 degrees, as per it's specs (0 to 300) full_angle = 300 while True: try: # Read sensor value from potentiometer sensor_value = bakebit.analogRead(potentiometer) # Calculate voltage voltage = round((float)(sensor_value) * adc_ref / 1023, 2) # Calculate rotation in degrees (0 to 300) degrees = round((voltage * full_angle) / bakebit_vcc, 2) # Calculate LED brightess (0 to 255) from degrees (0 to 300) brightness = int(degrees / full_angle * 255) # Give PWM output to LED bakebit.analogWrite(led,brightness) print("sensor_value = %d voltage = %.2f degrees = %.1f brightness = %d" %(sensor_value, voltage, degrees, brightness)) except KeyboardInterrupt: bakebit.analogWrite(led,0) 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_rotary_angle_sensor.py:
cd ~/BakeBit/Software/Python sudo python bakebit_rotary_angle_sensor.py
3.4 运行结果
旋转电位器,LED亮度会随着电位器的角度变化而变化。
4 示例程序(2):Servo and Rotary Angle Sensor
演示用电位器(Rotary Angle Sensor)来控制舵机的转动。
该示例是配合BakeBit - Servo来实现的,可参考BakeBit - Servo页面。
5 示例程序(3):LED Bar and Rotary Angle Sensor
这个示例实现类拟音量调节的效果,用到电位器模块和LED Bar。
该示例是配合BakeBit - LED Bar来实现的,可参考BakeBit - LED Bar页面。
6 相关资料
- [Schematic](BakeBit - Rotary Angle 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)