Noob Question: Sending Data to Serial Over CLI

Getting Started
1

I am just starting out and I am trying to write my very first test app. What I want to do is just print “Hi” onto the CLI when a key is pressed. But I am realizing that pressing of a key does not just send the data over the comm port (electron is hooked up to the USB and I am flashing using the USB / Win 10). What I am missing is a way for the CLI to just send text or anything really to the comm port. Can anyone help? Code so far:

void setup()
{
  Serial.begin(9600);
  
}

void loop()
{
while(!Serial.available()) Particle.process();
static bool wasExecuted = false;
     if (wasExecuted)
         return;
     wasExecuted = true;
     Serial.print("Hi");
}
2

particle serial monitor is only a monitor not a terminal :wink:
You can’t send serial data with this.

You’d rather need to use something like PuTTY or even just in cmd (assuming your device is registered as COM3)

echo > COM3
particle serial monitor
1 Like
3

Hi,

Here is some code that will echo back what you send it over the serial port:

void setup() {

    Serial.begin(9600);
}

void loop() {
    
    int availableBytes = Serial.available();
    
    if (availableBytes > 0) {
      
        char message[availableBytes];
      
        for(int i = 0 ; i < availableBytes ; i++) {
          
            message[i] = Serial.read();
        }

        Serial.println(message);
    }
    
    delay(1000);
}

But as @ScruffR says you cannot send data to the device using the serial monitor, only view the data written from the device.

On Ubuntu using the CLI you can use:

$> echo -e "hello world" > /dev/ttyACM0

To send the String “hello world” to the device and you will see it echoed back through the serial monitor.

Hope this is helpful!

4

There are tons of serial monitor programs that allow you to both send and receive but the particle serial monitor is not one of those. I just use the Arduino IDE’s built in monitor. There are probably some command line programs too

1 Like
5

Thanks all for the replies! This was very helpful! So, one follow-up question and then back to tinker mode for me: The reason I wanted to get this going was to use it as a standard debug tool to do things like print out the value of variables and registers ect. What does the community at large use for this? Do you guys just have a function that returns interesting variables? I’ll look into the Arduino IDE for now. Thanks again!

6

A quick update: I am using the Arduino IDE’s monitor and am happy as a clam!! Thank you Nimonster!

1 Like
7

Your welcome, for debugging I mainly publish events using Particle.publish but sometimes I use serial too. Serial is probably faster.