Debug print with ifdef and a header file

Updated on 2 December 2021

dev board Arduino M0

firmware Arduino

chip SAMD21

features debug ifdef print header

This tutorial is more than 1 year old. If the steps below do not work, then please check the latest versions and the documentations of the individual tools used.

Buy the components

RobotDyn M0 Mini

Code

Download code arduino-debug.ino

#define DEBUG  // Comment to turn off debug statements
#include "DebugUtils.h"

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);

  #ifdef DEBUG
  SerialUSB.begin(9600);
  while (!SerialUSB) { }
  delay(100);
  #endif

  DEBUG_PRINT("Start blinking");
}

void loop() {
  DEBUG_PRINT("HIGH");
  digitalWrite(LED_BUILTIN, HIGH);
  delay(500);

  DEBUG_PRINT("LOW");
  digitalWrite(LED_BUILTIN, LOW);
  delay(500);
}

Makefile

BOARD?=arduino:samd:mzero_bl
PORT := $(shell ls /dev/cu.usbmodem*)
BUILD=build

.PHONY: default lint all flash clean

default: lint all flash clean

lint:
	cpplint --extensions=ino --filter=-legal/copyright *.ino

all:
	arduino-cli compile --fqbn $(BOARD) --output-dir $(BUILD) ./

flash:
	arduino-cli upload --fqbn $(BOARD) --port $(PORT) --input-dir $(BUILD)

clean:
	rm -r build

Prototype

A photo of the actual setup.

Serial console

Serial output from the firmware.

Description

Some patterns for toggling on and off debug print messages in Arduino firmware with #ifdef and a header file DebugUtils.h.