receive multiple serail data in simulink frm arduino without delay

7 次查看（过去 30 天）
elham modaresi
elham modaresi 2019-10-31
评论： elham modaresi 2019-10-31
Hi Every one
I am using Matlab 2018 to receive multiple data from arduino. The Serial Receive block in Matlab 2018 has the pssibility of defining number of received data. So if I want to receive multiple data of size 2 (for examp.), I will set the data lenght to 2. However, If I try to send an array using the following code in arduino:
int a=10;
int b=20;
char c[2] = {a,b};
void setup() {
Serial1.begin(9600);
}
void loop() {
Serial1.write(c);
delay(100);
}
and use the fllowing simple simulink code to receive the array in simulink:
d1.png
I receive the folloing error:
Build process completed successfully
Error occurred while executing External Mode MEX-file 'ext_comm':
ExtTargetPktPending() call failed while checking for target pkt
If I try to send the array elements seperately in arduino like as:
int a=10;
int b=20;
void setup() {
Serial1.begin(9600);
}
void loop() {
Serial1.write(a);
Serial1.write(b);
delay(100);
}
again I receive the same error. However, if I use a delay between every two data like as:
int a=10;
int b=20;
void setup() {
Serial1.begin(9600);
}
void loop() {
Serial1.write(a);
delay(100);
Serial1.write(b);
delay(100);
}
then the receive block in simulink works correctly an I can get the data. But it makes no sense for me to send multiple data with delays between them. I need to send all of may data simultaneously. I just can have one delay (equal to my time step )at the end of sending all data synchronously.
Also, I should mention that if I set the delays equal to small vaclues(like 10ms), again I receive the same error.
I would appreciate if some one helps me on this.
  1 个评论
Walter Roberson
Walter Roberson 2019-10-31
char c[2] = {a,b};
That is not a byte.
That is not a string: it is not null terminated.
Serial1.write(c);
You can write() a byte or you can write a string.

请先登录，再进行评论。

请先登录，再回答此问题。

回答（3 个）

elham modaresi
elham modaresi 2019-10-31
Hi Walter
Tanks for your comment.
I modify the code as:
byte c[2];
c[0] =10;
c[1]=20;
void setup() {
Serial1.begin(9600);
}
void loop() {
Serial1.write(c,2);
//delay(10);
//Serial1.write(b);
delay(100);
}
Arduino gets an erre: 'c' does not have a type.
Could u pls modify it?
  3 个评论
显示 1更早的评论
Arun Kumar
Arun Kumar 2019-10-31
Move the assignment inside setup or loop, it should work fine.
byte c[2];
void setup() {
c[0] =10;
c[1]=20;
Serial1.begin(9600);
}
void loop() {
Serial1.write(c,2);
//delay(10);
//Serial1.write(b);
delay(100);
}
elham modaresi
elham modaresi 2019-10-31
I modify the arduino code as:
byte c[2];
void setup()
{
c[0] = 10;
c[1] = 20;
Serial1.begin(9600);
}
void loop()
{
Serial1.write(c, 2);
delay(100);
}
Now I do not get an an arduino error. but still I cannot receive the data in receive block in simulink I get the same error:
Build process completed successfully
Error occurred while executing External Mode MEX-file 'ext_comm':
ExtTargetPktPending() call failed while checking for target pkt
also I tested the code like this:
byte a =10;
byte b= 20;
void setup()
{
Serial1.begin(9600);
}
void loop()
{
Serial1.write(a);
Serial1.write("\n");
Serial1.write(b);
delay(100);
}
again same error I got.
It only works when I set a delay between two data.
But this is not possible for me. I wil also attach my simulink code in case.
Thanks,

请先登录，再进行评论。

Arun Kumar
Arun Kumar 2019-10-31
编辑：Arun Kumar 2019-10-31
Hi,
This code should work fine. I've checked with Arduino Uno and Mega
int a=10;
int b=20;
void setup() {
Serial1.begin(9600);
}
void loop() {
Serial1.write(a);
Serial1.write(b);
delay(100);
}
Delay is not required in between serial writes.
elham modaresi
elham modaresi 2019-10-31
but this does not work for me. I get the same error I mentioned before. I am using arduino Due. But I do not think this would make a problem.
I will attach my simulink code.
Could u pls have a look at it. Thanks in advance.
  3 个评论
显示 1更早的评论
Arun Kumar
Arun Kumar 2019-10-31
You need to move only the assignment, not the declaration. Since you are using the same variable in loop function also.
elham modaresi
elham modaresi 2019-10-31
I fixed the arduino code. It wont work without delays between data. How can I fix it please?

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 MATLAB Support Package for Arduino Hardware 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by