ESP32 485 Illuminance

气象站基础呀

RS-485仅是一个电气标准,描述了接口的物理层,像协议、时序、串行或并行数据以及链路全部由设计者或更高层协议定义.
RS-485定义的是使用平衡（也称作差分）多点传输线的驱动器（driver）和接收器（receiver）的电气特性.

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材料及接线

ESP32
单片机TTL转RS485模块

接线说明

开发板	TTL转RS485模块
22	TXD
23	RXD
5v	VCC
GND	GND

485光照度

采用工业级芯片,High-precision imported light sensor.采用RS485硬件接口,协议层兼容标准的工业Modbus-Rtu协议.

接线说明

TTL转RS485模块	485温湿度传感器	开发板
A+	TXD_A 黑线
B-	RXD_B 黄线
5v		5V 红线
GND	GND 绿线

PS：基本485的接线都一样了

示例程序

Get illuminance

此485传感器范围0~200000Lux

勒克斯(lux,Statutory symbolslx)照度单位,1 Lux equals 1流(lumen,lm)The luminous flux is evenly distributed in 1㎡ Illuminance over the area.
1 lx大约等于1candlelight in1Illuminance at a distance of meters,The lowest illuminance we commonly see in camera parameter specifications(MINIMUM.ILLUMINATION),Indicates that the camera only needs to be on the markedLUX数值下,That is, a clear image can be obtained,此数值越小越好,说明CCDhigher sensitivity.同样条件下,Black and white cameras require far less illuminance than color cameras that still have to deal with color intensity10倍.

一般情况:Under the summer sun100,000 lx;Cloudy outside for10000 lx;Indoor fluorescent lamps are100 lx;距60W台灯60CM桌面为300lx;TV studio for1000 lx;Indoors at dusk10 lx;Street lights at night0.1 lx;烛光(20CM远处)10~15 lx.

PS:我买的485The light can be measured outside the range after all20Wlx And the summer sun is there10Wlx.So if the test is outdoor,When buying, ask about the size. Indoor is0~65535lx

from machine import UART
#ESP32可以映射引脚,初始化的时候设置就行,串口号一般设置成2（0和1尽量别用.）
import time
uart= UART(2, baudrate=9600, bits=8, parity=None, rx=22,tx=23, stop=1, timeout=100) 
barray = bytearray([0x01,0x03,0x00,0x02,0x00, 0x02 ,0x65 ,0xcb])  #问询帧

while True:
    uart.write(barray)
    time.sleep(1) 
    if(uart.any()):
      u2by=uart.read()        # 返回的是答应帧的内容
      aa=u2by
      G10 = int.from_bytes(aa[3:5],'big')  # 十位
      G1= int.from_bytes(aa[5:7],'big')  # 个位
      GZ=G10*10+G1
      print(GZ,"LUX")

Serial output light value,I tested it indoors

修改地址

In addition, we can also configure the address.

The following addresses are configured successfully,My current sensor address is00

>>> from machine import UART
>>> uart= UART(2, baudrate=9600, bits=8, parity=None, rx=22,tx=23, stop=1, timeout=100) 
>>> barray = bytearray([0x00,0x06,0x00,0x20,0x00, 0x01 ,0x48 ,0x11])
>>> uart.write(barray)
8
>>> u2by=uart.read()
>>> print(u2by)
b'\x00\x06\x00 \xe1\xfd'

We can test it

from machine import UART
#ESP32可以映射引脚,初始化的时候设置就行,串口号一般设置成2（0和1尽量别用.）
import time
uart= UART(2, baudrate=9600, bits=8, parity=None, rx=22,tx=23, stop=1, timeout=100) 
barray = bytearray([0x00,0x03,0x00,0x02,0x00, 0x02 ,0x64 ,0x1A])  #问询帧

while True:
    uart.write(barray)
    time.sleep(1) 
    if(uart.any()):
      u2by=uart.read()        # 返回的是答应帧的内容
      aa=u2by
      G10 = int.from_bytes(aa[3:5],'big')  # 十位
      G1= int.from_bytes(aa[5:7],'big')  # 个位
      GZ=G10*10+G1
      print(GZ,"LUX")

Look no doubt,是好使的~