I need to use the method Serial.println() to read the serial buffer correctly. Without Serial.println() it does not read it.
A frame is received, which has a sync byte, a byte that is the sender address, a byte that is the destination address and a data byte
void client(){
String string, ax,aux;
char ax1,ax2,ax3,ax4;
string="";
ax="o1"; //the character is for frame synchronization and 1 is the client's address
aux="";
while (Serial.available() > 0) {
char c= Serial.read();
string=string+c;
Serial.println(c); //without this line the code does not work
}
aux=string;
ax1=string[0]; //sync byte
string="";;
string=aux;
ax2=string[1]; //sender address byte
string="";;
string=aux;
ax3=string[2];// destination address byte
string="";;
string=aux;
ax4=string[3]; //data byte
string="";;
string=aux;
Serial.println(string); //without this line the code does not work
if (ax1==ax[0] && ax3==ax[1] && ax4=='1'){
digitalWrite(A0,HIGH);
}
if (ax1==ax[0] && ax3==ax[1] && ax4=='0'){
digitalWrite(A0,LOW);
}
}
Related
I want to read in GPS Data from a serial port of a ublox chip. I do not only want to read in NMEA sentences but also Raw data (Messages like MEASX, RAWX,SFRBX). If I simply connect my serial ports with a pc and read in the data with RealTerm (win) it works fine. However if I try to read in the data with adruino it reads in the NMEA sentences fine but it does not manage to read in the raw data correctely.
Here is the code I use:
String inData;
void setup() {
Serial.begin(38400);
}
void loop() {
while (Serial.available() > 0)
{
char recieved = Serial.read();
inData += recieved;
// Process message when new line character is recieved
if (recieved == '\n')
{
//Serial.print("Arduino Received: ");
Serial.print(inData);
inData = ""; // Clear recieved buffer
}
}
}
Any ideas how to simply read in a file line by line. I think the problem is i do not know how to handle the raw data - how to read that data in?
Best
picture1 picture2
You don't need to check for CR, the GPS device sends the data in blocks, so if one block is done, the communication will be closed and the available()-statement will no longer be true.
if (gps.available())
{
String Buffer = "";
while (gps.available())
{
char GPSRX = gps.read();
Buffer += GPSRX;
//Serial.write(gps.read());
}
Serial.print(Buffer);
}
with 'gps' is an instance of SoftwareSerial:
#include <SoftwareSerial.h>
SoftwareSerial gps(4, 3); // RX, TX
...
void setup()
{
gps.begin(9600);
...
}
void loop()
{
if (gps.available())
{
...
}
...
}
I would like to detect a certain byte pattern in an incoming byte stream at the UART. I am using Arduino. Currently, the code detects a single \r character. On this character is detected, the byte stream before this character gets stored into a buffer. This is easy. This is my code;
int incomingByte = 0; // for incoming serial data
void setup() {
Serial.begin(9600); // opens serial port, sets data rate to 9600 bps
}
void loop() {
// send data only when you receive data:
if (Serial.available() > 0 ) {
// read the incoming byte:
incomingByte = Serial.read();
if (incomingByte != '\r') {
buffer_incoming_data[index_buffer]=incomingByte;
index_buffer++;
} else {
index_buffer = 0;
}
}
}
Here is my problem. Instead of a single character \r, I would like to detect a byte pattern that looks like this 0xAA 0xBB 0xCC. When this byte pattern is detected, the byte stream before byte pattern gets stored into a buffer.
Guess you invoke loop() method inside real loop operator. I can suggest next way:
int incomingByte = 0; // for incoming serial data
int pattern [] = {0xAA, 0xBB, 0xCC};
int patternIndex = 0;
int patternSize = sizeof(pattern)/sizeof(pattern[0]);
void loop() {
// send data only when you receive data:
if (Serial.available() > 0 ) {
// read the incoming byte:
incomingByte = Serial.read();
if(pattern[patternIndex] != incomingByte){
// if we found begin of pattern but didn't reach the end of it
if(patternIndex>0){
for(int i=0; i<=patternIndex-1; i++){
buffer_incoming_data[index_buffer]=pattern[i];
index_buffer++;
}
}
patternIndex = 0;
}
if(pattern[patternIndex] == incomingByte){
patternIndex++;
}else{
buffer_incoming_data[index_buffer]=incomingByte;
index_buffer++;
}
//if we reached the end of pattern
if(patternIndex==patternSize){
//do something with buffer
patternIndex = 0;
index_buffer = 0;
}
}
}
As you can see, I didn't check index_buffer for "index out of range" exception, but you should. Hope I helped you.
How To Read String from Arduino when am selecting no line ending at arduino serial monitor.
You typically use the line ending (CR+LF) to identify end of user input. In your case it is not clear what will be the end of line terminator. Assuming '.' (period) than you should consume characters from the Serial until you reach the line terminator.
Here's an example code:
#define EOL_TERMINATOR '.'
int inByte = 0; // incoming serial byte
String cmdLine;
void setup()
{
// start serial port at 9600 bps:
Serial.begin(9600);
cmdLine = "";
}
void loop()
{
// if we get a valid byte, read analog ins:
if (Serial.available() > 0) {
// get incoming byte:
inByte = Serial.read();
if (inByte != EOL_TERMINATOR)
cmdLine.concat(inByte);
else {
userCommand(cmdLine);
cmdLine = ""; //reset cmdLine for next command
}
}
}
void userCommand(String cmd) {
Serial.println("User command '"+cmd+"'");
}
I am doing some simple arduino projects in an effort to learn some of the basics.
For this project I am trying to print a line sent through the serial monitor. When I print the line, my leading text prints along with the first character of the user input, and then a new line starts and the leading text prints again along with the rest of the user data. I'm not sure why this is happening.
Here is my code:
char data[30];
void setup()
{
Serial.begin(9600);
}
void loop()
{
if (Serial.available())
{
//reset the data array
for( int i = 0; i < sizeof(data); ++i )
{
data[i] = (char)0;
}
int count = 0;
//collect the message
while (Serial.available())
{
char character = Serial.read();
data[count] = character;
count++;
}
//Report the received message
Serial.print("Command received: ");
Serial.println(data);
delay(1000);
}
}
When I upload the code to my Arduino Uno, and open the serial monitor, I can type in a string like: "Test Message"
When I hit enter, I get the following result:
Command received: T
Command received: est Message
When what I was expecting was:
Command received: Test Message
Can someone point me in the right direction?
Thanks in advance for the help.
Serial.available() doesn't return a boolean it returns how many bytes are in the Arduino's serial buffer. Because you are moving that buffer into a list of 30 chars you should check that the serial buffer is 30 chars long with the condition Serial.available() > 30.
This could be causing the code to execute once as soon as the serial buffer has any data, hence it running for the first letter then again realising more has been written to the buffer.
I'd recommend also completely removing your data buffer and using the data direct from the serial's buffer. e.g
Serial.print("Command received: ");
while (Serial.available()) {
Serial.print((char)Serial.read());
}
Edit: How to wait until serial data finishes being sent
if (Serial.available() > 0) { // Serial has started sending
int lastsize = Serial.available(); // Make a note of the size
do {
lastsize = Serial.available(); // Make a note again so we know if it has changed
delay(100); // Give the sender chance to send more
} while (Serial.available() != lastsize) // Has more been received?
}
// Serial has stopped sending
I want my Arduino to receive an integer through the serial communication. Can you help me with this?
It should be in a form like:
int value = strtoint(Serial.read());
There are several ways to read an integer from Serial, largely depending on how the data is encoded when it is sent. Serial.read() can only be used to read individual bytes so the data that is sent needs to be reconstructed from these bytes.
The following code may work for you. It assumes that serial connection has been configured to 9600 baud, that data is being sent as ASCII text and that each integer is delimited by a newline character (\n):
// 12 is the maximum length of a decimal representation of a 32-bit integer,
// including space for a leading minus sign and terminating null byte
byte intBuffer[12];
String intData = "";
int delimiter = (int) '\n';
void setup() {
Serial.begin(9600);
}
void loop() {
while (Serial.available()) {
int ch = Serial.read();
if (ch == -1) {
// Handle error
}
else if (ch == delimiter) {
break;
}
else {
intData += (char) ch;
}
}
// Copy read data into a char array for use by atoi
// Include room for the null terminator
int intLength = intData.length() + 1;
intData.toCharArray(intBuffer, intLength);
// Reinitialize intData for use next time around the loop
intData = "";
// Convert ASCII-encoded integer to an int
int i = atoi(intBuffer);
}
You may use the Serial.parseInt() function, see here: http://arduino.cc/en/Reference/ParseInt