AT 命令在程序中执行失败
AT Commands fail to Execute in a program
程序如下：
</p>
<pre><code>#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：
这些单独执行的命令就像 Charm 一样工作。
这里的主要问题是，当您调用 delay 而不是 读取和解析 从调制解调器返回的响应时，任何事情都不会可靠地或根本不会工作。您必须阅读并解析返回的回复。
尝试使用 delay 就像踢挡路的狗以让它们移动一样有用。是的，它有时可能确实有效，但在某些时候你会后悔采用这种方法......
有关如何正确执行此操作的一些指南，请参阅 this answer. I suspect that you possibly are aborting some of the commands, see the first part of this answer 以了解更多详细信息。
旁注：您应该始终在尽可能短的时间内禁用中断，因此您绝对应该将所有 Serial.print 移动到 attachInterrupt 之后。
程序如下：
</p>
<pre><code>#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：
这些单独执行的命令就像 Charm 一样工作。
这里的主要问题是，当您调用 delay 而不是 读取和解析 从调制解调器返回的响应时，任何事情都不会可靠地或根本不会工作。您必须阅读并解析返回的回复。
尝试使用 delay 就像踢挡路的狗以让它们移动一样有用。是的，它有时可能确实有效，但在某些时候你会后悔采用这种方法......
有关如何正确执行此操作的一些指南，请参阅 this answer. I suspect that you possibly are aborting some of the commands, see the first part of this answer 以了解更多详细信息。
旁注：您应该始终在尽可能短的时间内禁用中断，因此您绝对应该将所有 Serial.print 移动到 attachInterrupt 之后。