Difference between revisions of "BakeBit - LED Bar"
From FriendlyELEC WiKi
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* These five LEDs are in series connection. | * These five LEDs are in series connection. | ||
| − | == | + | ==Hardware Spec== |
| − | * | + | * Standard 2.0mm pitch 4-Pin BakeBit Interface |
| − | * | + | * Multi-color R, G, B LED |
| − | * | + | * True Color |
[[File:BakeBit - LED Bar_PCB.png | frameless|400px|BakeBit - LED Bar]] | [[File:BakeBit - LED Bar_PCB.png | frameless|400px|BakeBit - LED Bar]] | ||
| − | * | + | * Pin Description: |
{| class="wikitable" | {| class="wikitable" | ||
|- | |- | ||
| − | | | + | |Pin || Description |
|- | |- | ||
| − | |GND || | + | |GND || Ground |
|- | |- | ||
| − | |5V || | + | |5V || 5V Supply Voltage |
|- | |- | ||
| − | |NC || | + | |NC || Not Connected |
|- | |- | ||
| − | |SIG || | + | |SIG || Signal |
|} | |} | ||
| + | |||
== 示例程序(1)：LED Bar == | == 示例程序(1)：LED Bar == | ||
Revision as of 08:30, 13 December 2016
Contents
1 Introduction
- The BakeBit - LED-Bar is a multiple-LED module. It has five LEDs and each LED is controlled by a WS2812 chip.
- These five LEDs are in series connection.
2 Hardware Spec
- Standard 2.0mm pitch 4-Pin BakeBit Interface
- Multi-color R, G, B LED
- True Color
- Pin Description:
| Pin | Description |
| GND | Ground |
| 5V | 5V Supply Voltage |
| NC | Not Connected |
| SIG | Signal |
3 示例程序(1)：LED Bar
这个项目实现类拟音量调节的效果，用到电位器模块和LED Bar。
本示例需要配合BakeBit - Rotary Angle Sensor使用。
3.1 硬件连接
简单的将 LED Bar 模块插入 D3 接口，将 电位器 插入 A0 接口，如下面这样：
3.2 示例源代码
import time import bakebit import random # Connect the BakeBit LED Bar to digital port D3 # DI,DCKI,VCC,GND ledbar = 3 # Connect the BakeBit Rotary Angle Sensor to analog port A0 # SIG,NC,VCC,GND potentiometer = 0 # 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 360 degrees, as per it's specs (0 to 360) full_angle = 360 bakebit.pinMode(potentiometer,"INPUT") bakebit.pinMode(ledbar,"OUTPUT") time.sleep(1) # LED Bar methods # bakebit.bakeBitLedBar_Init(pin, chipset, numOfLED) # bakebit.bakeBitLedBar_Release(pin) # bakebit.bakeBitLedBar_Show(pin,colorHigh,colorLow) bakebit.bakeBitLedBar_Init(ledbar, 0, 5) time.sleep(.5) old_color = 0 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 360) degrees = round((voltage * full_angle) / bakebit_vcc, 2) print("sensor_value = %d voltage = %.2f degrees = %.1f" % (sensor_value, voltage, degrees)) color16bit = 0 if degrees > 0: color16bit = color16bit | bakebit.Green if degrees > 72: color16bit = color16bit | (bakebit.Green<<3) if degrees > 144: color16bit = color16bit | (bakebit.Green << 6) if degrees > 216: color16bit = color16bit | (bakebit.Yellow << 9) if degrees > 288: color16bit = color16bit | (bakebit.Red << 12) if degrees == 360: color16bit = 0 color16bit = color16bit | bakebit.Red color16bit = color16bit | (bakebit.Red << 3) color16bit = color16bit | (bakebit.Red << 6) color16bit = color16bit | (bakebit.Red << 9) color16bit = color16bit | (bakebit.Red << 12) if color16bit == old_color: continue old_color = color16bit lowBits = color16bit & 255 highBits = (color16bit & (255<<8))>>8 print("%s %s" % ('{0:08b}'.format(highBits), '{0:08b}'.format(lowBits))) bakebit.bakeBitLedBar_Show(ledbar, highBits, lowBits) time.sleep(.2) 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_LEDBar_And_RotaryAngleSensor.py:
cd ~/BakeBit/Software/Python sudo python bakebit_prj_LEDBar_And_RotaryAngleSensor.py
3.4 运行结果
旋转电位器，LED Bar上被点亮的LED个数将根据你的操作角度而进行变化。
4 示例程序(2)：Smart Lighting
该示例利用BakeBit - Light Sensor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。
该示例是配合BakeBit - Light Sensor来实现的，可参考BakeBit - Light Sensor页面。
5 相关资料
- [Schematic](BakeBit - LED Bar.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)
