Unexpected hexadecimal 00 send over serial communication
Hi,
I'm connecting a Tesa tt20 with a serial port. TT20 measures thickness and returns a 6 digit fractional number (0.0000). Communication works fine on most desktops and/or laptops. I have to say that i throw away the first measurement, because values where not to be trusted.
In one case, the following occures :
Sometimes there are gaps between the numbers.
Something like this : 1. 23 or 0.0 2
Examining this string in codes display, the gap appears to be \00 or in very rare cases \s
When we connect a laptop on the same TT20, communication works fine
It seems to be a problem with the desktop, some kind of setup -parameter ?
I was wondering if anyone has encoutered the same problem ?
Thanks in advance
Regards
Christine
Centerbolt,
I gathered a bit of info.
The same cable is used on desktop and portable
It seems to be an optical RS232
In attachment you will find the communications spec for the TT20. Not much to go on. But i am not a specialist on this.
I am using labv 8.2.1
You are right about the timing. I will make a version where i will make sure that the wait comes before the property node
Many thanks
Regards
Christine
Attachments:
RS232_UK pg80.jpg 73 KB
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Having issues with simple serial communication.
I followed a tutorial online to start learning basic serial communication. The tutorial involved shorting pins 1 and 3 on the Comm 1 port, and writing a simple program (attached). I edited the program a little, to show the varied results that I get when trying to write and read a simple phrase via serial port.
Could someone explain what causes the kind of result shown in "Serial Comm Example.png"? I believe it has to do with timing. Why would only parts of the phrase be transmitted?
Thanks,
Sarah
Solved!
Go to Solution.
Attachments:
Serial Comm Example.vi 30 KB
Serial Comm Example.png 139 KBsarahzig wrote:
The tutorial involved shorting pins 1 and 3 on the Comm 1 port
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digitalWrite(encoder1PinA, HIGH); // turn on pullup resistor
pinMode(encoder1PinB, INPUT);
digitalWrite(encoder1PinB, HIGH); // turn on pullup resistor
pinMode(encoder2PinA, INPUT);
digitalWrite(encoder2PinA, HIGH); // turn on pullup resistor
pinMode(encoder2PinB, INPUT);
digitalWrite(encoder2PinB, HIGH); // turn on pullup resistor
attachInterrupt(encoder1PinA, d1EncoderA, CHANGE);
attachInterrupt(encoder1PinB, d1EncoderB, CHANGE);
attachInterrupt(encoder2PinA, d2EncoderA, CHANGE);
attachInterrupt(encoder2PinB, d2EncoderB, CHANGE);
void loop() {
if(Serial2.available()>0){
String first = Serial2.readStringUntil('!');//랩뷰에서 받는 2개의 값을 분리하기 위한 소스("!"앞까지 끊고, "@"앞까지 끊음 ex)123!456@을 받으면 123과 456으로 나눔)
String second = Serial2.readStringUntil('@');//http://stackoverflow.com/questions/29504679/splitting-a-comma-separated-string-through-serial-arduino
float x = first.toFloat();//위에서 분리된 문자를 float형으로 바꿔줌
float y = second.toFloat();
newposition1 = -encoder1Pos; //Encoder signal
newposition2 = encoder2Pos; //Encoder signal
count_old = 0;
float power1 = x;
float power2 = y;
if(power1 >= 0){
Direction1 = LOW;
else{
Direction1 = HIGH;
if(power2 >= 0){
Direction2 = HIGH;
else {
Direction2 = LOW;
power1 = abs(power1);
power2 = abs(power2);
if(power1 > pwm1_limit){
power1 = pwm1_limit;
if(power2 > pwm2_limit){
power2 = pwm2_limit;
digitalWrite(DIR1, Direction1); //HIGH = back, LOW = forward
digitalWrite(DIR2, Direction2); //HIGH = back, LOW = forward
analogWrite(PWM1, power1);//PWM Speed Control
analogWrite(PWM2, power2);//PWM Speed Control
String strValue = String(newposition1);//숫자를 문자형으로 변환
String Q = "!";
String strValue2 = String(newposition2);
String stringThree = strValue + Q + strValue2;//문자 합치기
Serial2.println(stringThree);//Send encoder pulse to Labview
else {//when Serial communication stop
float count = count_old+1;
if(count > 10000){
newposition1 = 0; //Encoder initialization
newposition2 = 0; //Encoder initialization
encoder1Pos = 0;
encoder2Pos = 0;
else{
newposition1 = newposition1; //Encoder signal
newposition2 = newposition2; //Encoder signal
count_old = count;
Serial.println(count);
//Encoder Read//////////////////////////////////////////////////////////
void d1EncoderA()
Bnew1^Aold1 ? encoder1Pos++ : encoder1Pos--;
Aold1 = digitalRead(encoder1PinA);
void d1EncoderB()
Bnew1 = digitalRead(encoder1PinB);
Bnew1^Aold1 ? encoder1Pos++ : encoder1Pos--;
void d2EncoderA()
Bnew2^Aold2 ? encoder2Pos++:encoder2Pos--;
Aold2=digitalRead(encoder2PinA);
void d2EncoderB()
Bnew2=digitalRead(encoder2PinB);
Bnew2^Aold2 ? encoder2Pos++:encoder2Pos--;
}piZviZ wrote:
Only data rate working is 9600 between labview and launchpad(arm cortex m4).Where all data rates work between Arduino serial port monitor and launchpad(arm cortex m4).
Since the only thing that changed is the Launchpad, then that must be the issue. Are you sure this device can handle more than just the 9600 baud rate? Are you sure you are even setting the baud rate on this device?
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