(solved)SIM800L+Arduino (serial communications carrion return & lew line puzzling)

Dr_Doggy · Feb 18, 2016

Code:

void loop() {
char b[6];

//while(Serial.available()) //seems not needed afterall, at least not yet
//{
a= mySerial.readString();  //data from bluetooth
a.toCharArray(b, a.length());
Serial.println(a);

if(a=="OK" || a=="ok")
{
  digitalWrite(ledpin,HIGH);
delay(1000);
  digitalWrite(ledpin,LOW);

}
else
{
  blinkS(b);
}

//}
}

fezder · Feb 18, 2016

hmm led blinks 5 times at first, then even without even input it starts blinking again at same frequency....
Here, took output with analyzer, any help?
Channel 0 is RX, forgot to rename labels...

fezder · Feb 18, 2016

For reference, here is \r\nOK\r\n, sent from bluetooth, earlier was from SIM800

fezder · Feb 19, 2016

Here is decoded output, responce is indeed strange from sim800

Dr_Doggy · Feb 19, 2016

what about if you send KK? i have a feeling djs is on to something there with serial.read what if you tried a= serial.read; ?

Code:

void loop() {
string b = "";

//while(Serial.available()) //seems not needed afterall, at least not yet
//{
b= mySerial.readString();  //data from bluetooth
Serial.println(b);
a += b;
if (b == "\r" ){
a.replace("\n", ""); // cut \n out of a
a.replace("\r", "");
if(a=="OK" || a=="ok")
{
  digitalWrite(ledpin,HIGH);
delay(1000);
  digitalWrite(ledpin,LOW);
}
else
{
  blinkS(b);
}
a = "";
//}
}
}

fezder · Feb 19, 2016

Dr_Doggy said:
what about if you send KK? i have a feeling djs is on to something there with serial.read what if you tried a= serial.read; ?

KK doesn't light up led, and serial.read doesn't work at all if in place of serial.readString
still conversion error:

C:

Arduino: 1.6.7 (Windows 7), TD: 1.27, Board: "Arduino/Genuino Uno"

C:\Users\Atte\AppData\Local\Temp\arduino_44fcd912d8d04af8472eb3e2b373a47b\sketch_feb19a.ino: In function 'void loop()':

sketch_feb19a:54: error: cannot convert 'String' to 'const char*' for argument '1' to 'void blinkS(const char*)'

  blinkS(b);

  ^

exit status 1
cannot convert 'String' to 'const char*' for argument '1' to 'void blinkS(const char*)'

Invalid library found in C:\Users\Atte\Documents\Arduino\libraries\LCD_Spectrum_Analyzer: C:\Users\Atte\Documents\Arduino\libraries\LCD_Spectrum_Analyzer
Invalid library found in C:\Users\Atte\Documents\Arduino\libraries\LCD_Spectrum_Analyzer: C:\Users\Atte\Documents\Arduino\libraries\LCD_Spectrum_Analyzer

  This report would have more information with
  "Show verbose output during compilation"
  enabled in File > Preferences.

C:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); // RX, TX
String a;
int ledpin=13;


void blinkC(unsigned char b){
while (b>0){
  digitalWrite(ledpin,HIGH);
delay(200);
  digitalWrite(ledpin,LOW);
delay(200);
b--;
}
}

void blinkS(const char* ch){
  while (*ch )
  {
blinkC(*ch++);
delay(1000);

}
}

void setup()
{
pinMode(ledpin,OUTPUT);
Serial.begin(9600);  //harware serial
  mySerial.begin(9600);  //bluetooth module, for sending AT-commands
blinkC(5);
delay(1000);
}

void loop() {
String b = "";

//while(Serial.available()) //seems not needed afterall, at least not yet
//{
b= mySerial.readString();  //data from bluetooth
Serial.println(b);
a += b;
if (b == "\r" ){
a.replace("\n", ""); // cut \n out of a
a.replace("\r", "");
if(a=="OK" || a=="ok")
{
  digitalWrite(ledpin,HIGH);
delay(1000);
  digitalWrite(ledpin,LOW);
}
else
{
  blinkS(b);
}
a = "";
//}
}
}

Dr_Doggy · Feb 19, 2016

Code:

void loop() {
string b = "";

//while(Serial.available()) //seems not needed afterall, at least not yet
//{
b= mySerial.readString();  //data from bluetooth
Serial.println(b);
a += b;
if (b == "\r" ){
a.replace("\n", ""); // cut \n out of a
a.replace("\r", "");
if(a=="OK" || a=="ok")
{
  digitalWrite(ledpin,HIGH);
delay(1000);
  digitalWrite(ledpin,LOW);
}
a = "";
}
//}
}

fezder · Feb 22, 2016

Tested that, no change, didn't work. Buddy suggested firmware upgrade, could be worth shot.

Dr_Doggy · Feb 22, 2016

try this, watch the data being echoed in terminal, if printline(string) doesn't work just delete it..

Code:

void loop() {
string b = "";

//while(Serial.available()) //seems not needed afterall, at least not yet
//{
b= mySerial.readString();  //data from bluetooth
Serial.println("string:");
Serial.println(b);
a += b;
Serial.println(a);
a.replace("\n", ""); // cut \n out of a
a.replace("\r", "");
if(a=="OK" || a=="ok")
{
  digitalWrite(ledpin,HIGH);
delay(1000);
  digitalWrite(ledpin,LOW);
a = "";
}

//}
}

fezder · Feb 23, 2016

hmm, serial shoots carbage out in arduino serial, baudrate matches though, it shoots out ÿÿÿÿÿ, if receives "OK" from sim800L, if I send "<cr><lf>OK<cr><lf>, output is ÿÿÿ

djsfantasi · Feb 23, 2016

Does the number of bits, parity and stop bits match? What is the speed?

fezder · Feb 24, 2016

yes, they all match,9600 baud, none parity, 1 stop bit, 8 bits
IPR returs 0=auto baud, ICF returs 3,255=8 data 0 parity 1 stop (none parity)

fezder · Feb 24, 2016

This is one of many test codes, so it can be used with arduino:

C:

#include <SoftwareSerial.h>
#include <String.h>
String lat = "52.6272690";
String lng = "-1.1526180";
SoftwareSerial sim800l(10, 11); // RX, TX
float sensorValue;
const int buttonPin = 7;
int buttonState = 0;
float tempC;
float tempCavg;
int avgcount = 0;
void setup()
{

pinMode(buttonPin, INPUT);
sim800l.begin(9600);
Serial.begin(9600);
delay(500);
}

void loop()
{


buttonState = digitalRead(buttonPin);

if (buttonState == 0) {
while(avgcount < 50){
sensorValue = analogRead(A0);
tempC = sensorValue * 5.0;
tempC = tempC / 1024.0;
tempC = (tempC - 0.05) * 100;
tempCavg = tempCavg + tempC;
avgcount++;
}
delay(300);
Serial.println(tempCavg/ 50);
tempCavg = tempCavg / 50;
SendTextMessage();

}

if (sim800l.available()){
Serial.write(sim800l.read());
}
}

void SendTextMessage()
{
Serial.println("Sending Text...");
sim800l.print("AT+CMGF=1\r"); // Set the shield to SMS mode
delay(100);

sim800l.print("AT+CMGS=\"+44795*******\"\r");
delay(200);
// sim800l.print("http://maps.google.com/?q=");
// sim800l.print(lat);
// sim800l.print(",");
// sim800l.print(lng);
sim800l.print("The temperature is: ");
sim800l.print(tempCavg);
sim800l.print(" degrees C");
sim800l.print("\r"); //the content of the message
delay(500);
sim800l.print((char)26);//the ASCII code of the ctrl+z is 26 (required according to the datasheet)
delay(100);
sim800l.println();
Serial.println("Text Sent.");
delay(500);
tempCavg = 0;
avgcount = 0;
}

void DialVoiceCall()
{
sim800l.println("ATD+4479********;");//dial the number, must include country code
delay(100);
sim800l.println();
}

fezder · Feb 24, 2016

and just while ago tested that sketch as working, so this is interesting problem, sim module works whatever i send it to do, but when trying to interface it so it controls arduino, no-go.
But, there is read-from-sim800 function in that code too

djsfantasi · Feb 24, 2016

The only reference to the data speed of the SIM800 in the provided data sheet was 115200? How have you changed it to 9600?

fezder · Feb 24, 2016

So far I haven't changed anything, it was 9600 from the beginning; only boot-data is send at higher baud, 115200 that tells sms ready and stuff like that. Normal data is then sent with 9600 baud, or whatever is set. See AT+IPR from datasheet, that can be used to set baud

Dr_Doggy · Feb 25, 2016

so baud does match in terminal? maybe try changing it to the next one over?

fezder · Feb 26, 2016

I got it working! turned out, sim echoed command sent to it, and I figured that out by using LCD as translator what it actually sends, so \r and \n showed as random gibberish. So, we were close, here's final code:

C:

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); // RX, TX
String a;
int ledpin=13;

void setup()
{
pinMode(ledpin,OUTPUT);
Serial.begin(9600);  //harware serial
  mySerial.begin(9600);  //bluetooth module, for sending AT-commands
}

void loop() {
//while(Serial.available()) //seems not needed afterall, at least not yet. In fact, if this string is enabled, hardware serial MUST be open to this sketch work.
//{

a= mySerial.readString();  //data from bluetooth
Serial.println(a);
if(a=="AT\r\r\nOK\r\n")   //here is command echoed, as well as responce, so structure is <command>\r\r\n<response>\r\n
{
  digitalWrite(ledpin,HIGH);
}
else
{
  digitalWrite(ledpin,LOW);
}
//}
}

and this code I used as translator so to say:

C:

#include <Wire.h>
#include <LiquidTWI.h>

// Connect via i2c, default address #0 (A0-A2 not jumpered)
LiquidTWI lcd(0);
String a;


void setup() {
  lcd.begin(20, 4);
  Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}

void loop() {

  while (Serial.available()) {
lcd.setCursor(0,0);
  a = Serial.readString(); // read the incoming data as string
  Serial.print(a);
  lcd.print(a);
  lcd.print("  ");
  }
}

and lcd's output

Thanks for help!

fezder · Feb 27, 2016

only now I'd like to get rid of those garbage characters.....tips?

fezder · Feb 27, 2016

found help to this possibly while browsing, will try those later (echo off & discard cr and similar characters)

(solved)SIM800L+Arduino (serial communications carrion return & lew line puzzling)

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