树莓派红外反射传感器（Python程序）

1，工具

rpi3，微雪ARPI600，Infrared Reflective Sensor

2，基本原理

Infrared Reflective Sensor 输出数字和模拟信号

模拟信号通过ARPI600上的AD转换芯片TLC1543进行转换

TLC1543通信使用rpi的GPIO口，模拟SPI，进行模拟信号输入端口选择，和输出读取

程序通过读取DOUT判断与障碍物接近和远离

在接近障碍物时读取AD转换数值

3，连接实物

4，python程序（根据ARPI600提供程序修改）

#!/usr/bin/python
# -*- coding:utf-8 -*-
import RPi.GPIO as GPIO
import time

Clock = 16
Address = 20
DataOut = 21
DOUT = 17


def ADC_Read(channel):
    value = 0;
    for i in range(0,4):
        if((channel >> (3 - i)) & 0x01):
            GPIO.output(Address,GPIO.HIGH)
        else:
            GPIO.output(Address,GPIO.LOW)
        GPIO.output(Clock,GPIO.HIGH)
        GPIO.output(Clock,GPIO.LOW)
    for i in range(0,6):
        GPIO.output(Clock,GPIO.HIGH)
        GPIO.output(Clock,GPIO.LOW)
    time.sleep(0.001)
    for i in range(0,10):
        GPIO.output(Clock,GPIO.HIGH)
        value <<= 1
        if(GPIO.input(DataOut)):
            value |= 0x01
        GPIO.output(Clock,GPIO.LOW)
    return value

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
GPIO.setup(Clock,GPIO.OUT)
GPIO.setup(Address,GPIO.OUT)
GPIO.setup(DataOut,GPIO.IN,GPIO.PUD_UP)
GPIO.setup(DOUT,GPIO.IN)

lastdata = 2
try:
    while True:
        data = GPIO.input(DOUT)
        if lastdata and (lastdata == 1):
            continue
        if data == 0:
            print 'Near the Obstacles'
            print 'AD: %d ' % ADC_Read(6)
        if data == 1:
            print 'Far the Obstacles'
        lastdata = data
        time.sleep(0.1)
except:
    GPIO.cleanup()