AT 命令无法在程序中执行 [英] AT Commands fail to Execute in a program
问题描述
程序如下图:
<代码>
#include <SoftwareSerial.h>
SoftwareSerial gprsSerial(7, 8);
byte sensorInterrupt = 0; // 0 = digital pin 2
byte sensorPin = 2;
// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
// litre/minute of flow.
float calibrationFactor = 4.5;
volatile byte pulseCount;
float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;
unsigned long oldTime;
void setup()
{
gprsSerial.begin(19200);
Serial.begin(19200);
pinMode(sensorPin, INPUT);
digitalWrite(sensorPin, HIGH);
pulseCount = 0;
flowRate = 0.0;
flowMilliLitres = 0;
totalMilliLitres = 0;
oldTime = 0;
// The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
// Configured to trigger on a FALLING state change (transition from HIGH
// state to LOW state)
attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
Serial.println("Config SIM900...");
delay(2000);
Serial.println("Done!...");
gprsSerial.flush();
Serial.flush();
// attach or detach from GPRS service
gprsSerial.println("AT+CGATT?");
delay(100);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=3,1,\"CONTYPE\",\"GPRS\"");
delay(2000);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=3,1,\"APN\",\"uninor\"");
delay(3000);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=1,1");
delay(2000);
toSerial();
// bearer settings
gprsSerial.println("AT+SAPBR=2,1");
delay(3000);
toSerial();
gprsSerial.println("AT+HTTPINIT");
delay(2000);
toSerial();
}
void loop()
{
if ((millis() - oldTime) > 1000) // Only process counters once per second
{
// Disable the interrupt while calculating flow rate and sending the value to
// the host
detachInterrupt(sensorInterrupt);
// Because this loop may not complete in exactly 1 second intervals we calculate
// the number of milliseconds that have passed since the last execution and use
// that to scale the output. We also apply the calibrationFactor to scale the output
// based on the number of pulses per second per units of measure (litres/minute in
// this case) coming from the sensor.
flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
// Note the time this processing pass was executed. Note that because we've
// disabled interrupts the millis() function won't actually be incrementing right
// at this point, but it will still return the value it was set to just before
// interrupts went away.
oldTime = millis();
// Divide the flow rate in litres/minute by 60 to determine how many litres have
// passed through the sensor in this 1 second interval, then multiply by 1000 to
// convert to millilitres.
flowMilliLitres = (flowRate / 60) * 1000;
// Add the millilitres passed in this second to the cumulative total
totalMilliLitres += flowMilliLitres;
unsigned int frac;
// Print the flow rate for this second in litres / minute
Serial.print("Flow rate: ");
Serial.print(int(flowRate)); // Print the integer part of the variable
Serial.print("L/min");
Serial.print("\t"); // Print tab space
// Print the cumulative total of litres flowed since starting
Serial.print("Output Liquid Quantity: ");
Serial.print(totalMilliLitres);
Serial.println("mL");
Serial.print("\t"); // Print tab space
Serial.print(totalMilliLitres / 1000);
Serial.print("L");
// Reset the pulse counter so we can start incrementing again
pulseCount = 0;
// Enable the interrupt again now that we've finished sending output
attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
}
// set http param value
gprsSerial.println("AT+HTTPPARA=\"URL\",\"http://210.16.100.71:8090/watersupply/webservices/test.php?flowratereading=1500\"");
delay(2000);
toSerial();
// set http action type 0 = GET, 1 = POST, 2 = HEAD
gprsSerial.println("AT+HTTPACTION=0");
delay(6000);
toSerial();
// read server response
gprsSerial.println("AT+HTTPREAD");
delay(1000);
toSerial();
gprsSerial.println("");
delay(10000);
}
void toSerial()
{
while (gprsSerial.available() != 0)
{
Serial.write(gprsSerial.read());
}
}
void pulseCounter()
{
// Increment the pulse counter
pulseCount++;
}
上述程序中的 AT 命令没有立即执行并显示错误:串行监视器上的结果如下所示:
AT Commands in the above program are not executing at once and showing Error: The result on the Serial monitor is shown below:
这些单独执行的命令就像 Charm 一样工作.
These Commands Executed Separately works like Charm.
推荐答案
这里的主要问题是当你调用 delay
而不是 reading 和 parsing 时,没有任何东西可以可靠地工作或根本无法工作 从调制解调器返回的响应.您必须阅读并解析返回的回复.
The main issue here is that nothing will ever work reliably or at all when you call delay
instead of reading and parsing the responses given back from the modem. You MUST read and parse the responses given back.
尝试使用 delay
就像踢挡你路的狗以让它们移动一样有用.是的,它可能在某些时候确实有效,但在某些时候你会后悔采取这种方法......
Attempting to use delay
is as useful as kicking dogs that stand in your way in order to get them to move. Yes it might actually work some times, but at some point you will be sorry for taking that approach...
有关如何正确执行此操作的一些指南,请参阅此答案.我怀疑您可能正在中止某些命令,请参阅 此答案 的第一部分,了解更多详情.
For some guidelines of how to do this properly see this answer. I suspect that you possibly are aborting some of the commands, see the first part of this answer for some more details regarding that.
旁注:你应该总是在尽可能短的时间内禁用中断,所以你一定要把所有那些 Serial.print
移到 attachInterrupt
之后.
Side note: You should always disable interrupts for a period as short as possible, so you should definitely move all those Serial.print
to after attachInterrupt
.
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