0
我通过USB连接了Raspberry Pi和Arduino。 Arduino通过传感器（EC和温度传感器）从世界上获取数据并将这些数据写入串口。 Raspberry将这些数据写入数据库。通过pyserial的树莓Arduino通信在一天后停止
Arduino的草图：在树莓派
#include <OneWire.h>
#include <DallasTemperature.h>
int R1= 500;
int Ra=25; //Resistance of powering Pins
int ECPin= A0;
int ECGround=A1;
int ECPower =A4;
float PPMconversion=0.7;
float TemperatureCoef = 0.019;
float K=2.88;
#define ONE_WIRE_BUS 10 // Data wire For Temp Probe is plugged into pin 10 on the Arduino
const int TempProbePossitive =8; //Temp Probe power connected to pin 9
const int TempProbeNegative=9; //Temp Probe Negative connected to pin 8
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature sensors(&oneWire);// Pass our oneWire reference to Dallas Temperature.
float Temperature=10;
float EC=0;
float EC25 =0;
int ppm =0;
float raw= 0;
float Vin= 5;
float Vdrop= 0;
float Rc= 0;
float buffer=0;
void setup()
{
Serial.begin(9600);
pinMode(TempProbeNegative , OUTPUT); //seting ground pin as output for tmp probe
digitalWrite(TempProbeNegative , LOW);//Seting it to ground so it can sink current
pinMode(TempProbePossitive , OUTPUT);//ditto but for positive
digitalWrite(TempProbePossitive , HIGH);
pinMode(ECPin,INPUT);
pinMode(ECPower,OUTPUT);//Setting pin for sourcing current
pinMode(ECGround,OUTPUT);//setting pin for sinking current
digitalWrite(ECGround,LOW);//We can leave the ground connected permanantly
delay(100);// gives sensor time to settle
sensors.begin();
delay(100);
R1=(R1+Ra);// Taking into acount Powering Pin Resitance
};
void loop()
{
GetEC();
PrintReadings(); // Cals Print routine [below main loop]
delay(20000);
}
void GetEC(){
sensors.requestTemperatures();// Send the command to get temperatures
Temperature=sensors.getTempCByIndex(0); //Stores Value in Variable
digitalWrite(ECPower,HIGH);
raw= analogRead(ECPin);
raw= analogRead(ECPin);// This is not a mistake, First reading will be low beause if charged a capacitor
digitalWrite(ECPower,LOW);
Vdrop= (Vin*raw)/1024.0;
Rc=(Vdrop*R1)/(Vin-Vdrop);
Rc=Rc-Ra; //acounting for Digital Pin Resitance
EC = 1000/(Rc*K);
EC25 = EC/ (1+ TemperatureCoef*(Temperature-25.0));
ppm=(EC25)*(PPMconversion*1000);
}
void PrintReadings(){
Serial.print("Rc: ");
Serial.print(Rc);
Serial.print(" EC: ");
Serial.print(EC25);
Serial.print(" Simens ");
Serial.print(ppm);
Serial.print(" ppm ");
Serial.print(Temperature);
Serial.println(" *C ");
Serial.print("Vdrop: ");
Serial.println(Vdrop);
Serial.print("Rc: ");
Serial.println(Rc);
Serial.print(EC);
Serial.println("Siemens");
};
代码：
import serial
import time
import re
import sqlite3
for com in range(0,4):
try:
PORT = '/dev/ttyACM'+str(com)
BAUD = 9600
board = serial.Serial(PORT,BAUD)
board.close()
break
except:
pass
DEVICE = '/dev/ttyACM'+str(com)
BAUD = 9600
s = serial.Serial(DEVICE, BAUD)
conn=sqlite3.connect('mydatabase.db')
cursor=conn.cursor()
#s.open()
time.sleep(5) # der Arduino resettet nach einer Seriellen Verbindung, daher muss kurz gewartet werden
#s.write("test");
while True:
response = s.readline()
numbers = re.findall(r"[-+]?\d*\.\d+|\d+", response)
if len(numbers) == 4:
temp = numbers[3]
ec = numbers[1]
result = cursor.execute("INSERT INTO sensordata (temp, ec) VALUES ({temp}, {ec})".form$
conn.commit()
print response
数据对树莓侧约24小时写的，然后我从没有Arduino的串行输出了。同样的问题，当我重新启动python脚本。当我重新启动python脚本并且串行通信再次启动时，Arduino重置。我没有改变这种默认行为。我仍然没有通过串口获取数据的事实表明，在Arduino方面它没有内存问题。还有一点提示，它必定是Raspberry的一个问题，我能从重启Raspberry解决问题以及数据记录24小时的事实中得到什么。
有没有人有足够的好奇给我一个提示，如何建立一个坚实的沟通？
只是一些建议。在树莓上为主循环添加一些延迟，以便CPU不被100％使用。这可能不是问题，但它可能有帮助。在Arduino上添加GetEC函数中的其他序列打印（在树莓上你会忽略），这样你就可以看到它是否总是停在同一行。 – ChatterOne
Thx，ChatterOne供您评论。没有收到任何电子邮件以识别您的活动。不知何故，python设法无论如何都增加了延迟。根据命令行工具顶部有很多空闲时间。是的，我在每条命令后添加了串行打印，这让我进一步观察，看到我的答案 –