Handling Serial Input on Arduino with Interrupts on a specific character?

Question

I'm working on an educational robotics project that should allow control of the robot over Bluetooth. The robot is a off the shelf robot with a serial interface that the Arduino is driving normally autonomously.

What I'm trying to do is allow users to write a series of commands to the Bluetooth serial port (connected to hardware serial pins or software serial pins) while the automation is still running and when they send new-line, the series of commands is sent to other parts of the robot.

I've used other microcontrollers and written a simple interrupts when a pin is pulled high or low, but am not sure how to handle a an interrupt on a character. I think that an interrupt is the best way to do this, but I haven't had much experience with Arduino so there many be functionality I'm not aware off.

TL;DR: If I want the arduino to execute code when a certain character arrives on a serial port, should I use an interrupt method?

I also want to add, as this is an educational project, I would like to stay fully on Arduino, several friends and colleagues have recommended alternate chips or MCUs that would have the functionality but I want to stay friendly to new programmers and engineers.

slash-dev slash-dev · Accepted Answer · 2015-11-22T02:40:40

The built-in HardwareSerial does not have support for interrupt-driven handling of characters. Many sketches are OK with the typical polling approach:

while (Serial.available()) {
  char c = Serial.read();

  // code that watches for certain characters
  .
  .
  .
}

There's nothing about what you describe that requires interrupts, but you could use an extended version of HardwareSerial that I wrote (modified), called NeoHWSerial. It calls a function that you provide from the Interrupt Service Routine (see docs).

Handling Serial Input on Arduino with Interrupts on a specific character?

1 Answers