Published December 6, 2019 © LGPL

Arduino Nano 33 IoT Debugging

Get your Nano 33 IoT board connected to full GDB debugging so you can solve those bugs and get your project released!

AdvancedFull instructions provided12,044

Things used in this project

Hardware components

Arduino Nano 33 IoT

Female/Female Jumper Wires

(can just cut 3 in half)

Segger J-Link Probe

Software apps and online services

Arduino IDE

Microsoft Visual Studio 2017

Visual Micro

Hand tools and fabrication machines

Soldering iron (generic)

Solder Wire, Lead Free

Solder Flux, Soldering

(may be in your solder already)

Story

There is nothing more frustrating than a project nearly working as intended, and there is only so much you can print to serial to understand your code.

This is where debugging tools come in to allow you to stop the code executing at specific points, and allow you to inspect the variables, and move through the code line by line if desired.

We can use the GDB debugging system and an external hardware debugger with the Arduino Nano 33 IoT board thanks to its breakouts with a little soldering.

With the Arduino IDE + Visual Micro + Visual Studio software set we have the full IDE experience along with these debugging tools out of the box.

The Soldering

Before we can connect our Nano 33 IoT board to our external debugger, we need to connect some female jumper wires onto the pads on the back of the board as below.

1 / 2 • Location of the solder pads on the Nano 33 IoT (and BLE) board

An External Hardware Debugger

There are a variety of external hardware debugging devices available, and in this example we will be using the Segger J-Link debugger (EDU available for Educational use at a lower cost).

Other debuggers such as the Black Magic Probe are also available, and connect in the same way as shown here, and it is available in Visual Micro already. You can also make your own Probe as shown in our Nano 33 BLE article.

The connections between the two devices are shown below.

1 / 2 • Wiring Diagram for the Nano 33 IoT => Segger JLink (SWD)

Driver Setup

Some debuggers need an additional USB Driver installing on Windows to allow the debugging work correctly.

In our J-Link example you will need the Zadig tool, and to install the driver so they match in the tool.

Open the Zadig tool after downloading

Select Options > List All Devices

Now drop down the device list and select your device (JLink in this case).

If two devices are present select the "Interface 0" of the device

If the driver versions do not match, click Install Driver

There is a handy list of debugger / additional driver information on this page.

Debugging Setup

Once you are setup with the Arduino IDE + Visual Studio + Visual Micro, you can start debugging straight away.

Simply open your project and select the correct board and COM port.

Now you can set the debugger to "Hardware" which will expose a new list of pre-configured debuggers.

Select the one you are using, and ensure the vMicro > Debugger > Optimisation is set to "No Project + Libraries".

Add a breakpoint in where you want to stop initially, these can be moved once you have started the debugger, and there is often a limit of 6 concurrent breakpoints.

Now simply build and upload your code, and attach the debugger. You can also do this in one step by simply pressing Debug > Start Debugging.

A video of this Debugging Setup section is below:

Debugging process on the Nano33 IoT

Solve Those Problems

You should now be stopped on your break point, and a number of other windows are available on the Debug > Windows menu, if you do not see all of the watches / autos, etc.. windows that you wish to use.

Using the stepping and inspection tools, you can now move through the code to find the issues.

Useful Links

Getting started with the Arduino NANO 33 IoT

Segger J-Link Debug Probes

Segger EDU Debug Probes

Black Magic Wiki and Hardware Listing / Vendors

Zadig USB Driver Tool

Visual Micro - Nano 33 IoT Debugging Overview

Visual Micro - Debugger Support Listing (All)

Tutorial: Create Debug Probe and Use with Nano 33 BLE

Code

const int motor = 12;
int currentMotorPWM = 0;
unsigned long currentPeriodStartTime = 0;
unsigned int currentPeriod_MS = 1000;
unsigned int currentResolution = 254;
unsigned int maxResolution = 254;
int currentPWMVal = 0;
unsigned long loopCounter = 0;

void setup() {
	pinMode(motor, OUTPUT);
	analogWrite(motor, currentPWMVal);
}

void loop() {
	currentPWMVal = calculateCurrentPWM_sine((millis() - currentPeriodStartTime) % currentPeriod_MS);
	pwmWrite(currentPWMVal);
	loopCounter++;
}

// Encapsualtion 
int calculateCurrentPWM_spiky(unsigned long periodTime) {
	return calculateCurrentPWMMultiplier(periodTime) * currentResolution;
}

int calculateCurrentPWM_sine(unsigned long periodTime) {
	return
		round(
			abs(int(
			(
				sin(
				(
					double(calculateCurrentPWM_spiky(periodTime))
					/ 165.00
					)
				)
				)
				* double(currentResolution)
				)
			)
		);
}


int oldValue = -1;
void pwmWrite(int value) {
	if (oldValue != value) {
		analogWrite(motor, value);
		oldValue = value;
		Serial.print(",");
		Serial.print(value);
	}
}

double calculateCurrentPWMMultiplier(unsigned long periodTime) {
	if ((double(periodTime % currentPeriod_MS) / double((currentPeriod_MS / 2.00))) <= 1.00) {
		return (double(periodTime % currentPeriod_MS) / double((currentPeriod_MS / 2.00)));
	}
	else {
		return (1.00 - ((double(periodTime % currentPeriod_MS) - double((currentPeriod_MS / 2.00))) / double((currentPeriod_MS / 2.00))));
	}
}

Credits

arduinocc

2 projects • 13 followers

Arduino Nano 33 IoT Debugging

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

The Soldering

An External Hardware Debugger

Driver Setup

Debugging Setup

Solve Those Problems

Useful Links

Schematics

Arduino Nano 33 IoT to Debugger Wiring

Code

Nano33IoTProject.ino

Calcs.ino

Credits

arduinocc

Comments

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Arduino Nano 33 IoT Debugging

Arduino Nano 33 IoT Debugging

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

The Soldering

An External Hardware Debugger

Driver Setup

Debugging Setup

Solve Those Problems

Useful Links

Schematics

Arduino Nano 33 IoT to Debugger Wiring

Code

Nano33IoTProject.ino

Calcs.ino

Credits

arduinocc

Comments

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