With Xojo Dojo you get a simple code editor where you can write code using the Xojo programming language and a small set of additional commands for graphics, GPIO and some other things. It’s a great way to learn programming basics. Xojo Dojo includes several sample scripts to get you started.

For more information, check out the Xojo Dojo doc page.

Download the source from GitLab.

Add your #JustCode project to the week 11 forum conversation.

Download and check out earlier projects:

• Week 10: NetTank
• Week 9: Quote Web Service
• Week 8: JumpStart App Launcher
• Week 7: Pitch Tracker
• Week 6: Bubble Popper
• Week 5: Math Quiz
• Week 4: Mini-Golf ScoreKeeper
• Week 3: Dogs Up!
• Week 2: Password Generator
• Week 1: Color Picker

sudo apt-get install libunwind8

The Raspberry Pi OS (Raspbian) does not automatically update itself. Since it is always a good idea to keep your Pi up to date, you can do it easily from Terminal using these commands:

sudo apt-get update
sudo apt-get upgrade

To learn more about Raspberry Pi and Xojo:

• Getting Started with Raspberry Pi
• Programming the Raspberry Pi with Xojo book

And don’t forget, you can build Console and Desktop apps for Raspberry Pi with your free Xojo license.

UPDATE: Now with Xojo 2019r1, you can develop and build console and desktop apps for the Raspberry Pi for free! Download today and get started! Xojo Pi supports Raspberry Pi 2, 3 & 4.

Back at XDC 2015 when we announced Xojo would be adding support for the Raspberry Pi, we thought it was a fun extra for Xojo users. We were not expecting the overwhelming excitement and interest from the Xojo community and makers around the world! To celebrate Pi Day like the true geeks we are, we’re making Xojo Pi licenses free from Pi Day & forever!

Email hello@xojo.com for your free Xojo Pi license activation code.

Share the new with you friends, we’re on Twitter, Facebook, Instagram and LinkedIn.

UPDATED: 4/8/2019

I decided what would work for me is to have demo app automatically launch when the Pi boots. This would allow me to demo the app and project anywhere just by plugging in the Pi. There are several ways that a Pi can automatically start an app. After doing a bit of Google research I decided on this approach:

1. Open the /etc/rc.local file (you’ll want to use sudo):

   sudo nano /etc/rc.local

2. Add lines to automatically start the app you want. My app was a console app that used GPIO, so I added these two lines:

   export WIRINGPI_GPIOMEM=1
   /home/pi/Documents/Xojo/LCDPanel &

For reference, this is my rc.local file contents:

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
 printf "My IP address is %s\n" "$_IP"
fi

export WIRINGPI_GPIOMEM=1
/home/pi/Documents/Xojo/LCDPanel/LCDPanel &

exit 0

You can develop and build console and desktop apps for the Raspberry Pi using Xojo 2019r1 or later for free.

Download Xojo today and get started!

Fun times at XDC:

Download Xojo today and get started with this simple music player app for your Raspberry Pi that can play mp3 and aac (m4a) files from a folder.

By default Raspberry Pi sound output is sent to the HDMI port. There is also a headphone port that can be used for sound output to make it easier to hook up speakers. To switch between the sound outputs, you use this command at the Terminal:

sudo amixer cset numid=3 1

Other values you can use are: 0=auto, 1=headphones, 2=HDMI.

Create the Project

Create a Desktop project and call it MP3Player. For controls, you will add three buttons and a label to Window1. Arrange them to look like this:

Change the name of the label from “Label1” to “NowPlayingLabel” and make it as wide as the window.

Now add these properties to keep track of the song files to play and the currently playing song sound:

CurrentSong As Sound
CurrentSongIndex As Integer
Songs() As FolderItem

The music files are loaded as Sound objects and the CurrentSong property is the song that is currently playing. The Songs() array is an array of the MP3 and AAC files that were loaded from the selected folder. And the CurrentSongIndex is the position of the current file (in the array) to play.

With this setup out of the way, you can start adding code. The first thing to do is to load the music files from the selected folder. Add the Action event to the “Choose Music Folder” button and enter this code:

' Choose a folder, grab all music files in the folder
' and save in array
Dim musicFolder As FolderItem = SelectFolder
If musicFolder <> Nil Then
  CurrentSongIndex = -1
  ReDim Songs(-1)
 
  Dim count As Integer = musicFolder.Count
  For i As Integer = 1 To count
    Dim f As FolderItem = musicFolder.Item(i)
    If f <> Nil And (f.Name.Right(3) = "mp3" Or f.Name.Right(3) = "m4a") Then
      Songs.Append(f)
    End If
  Next
End If

PlayNextSong

The last line calls a method, PlayNextSong, that starts playing the next song in the array. Here is the code for the PlayNextSong method:

Sub PlayNextSong()
  If CurrentSong <> Nil Then CurrentSong.Stop
 
  CurrentSongIndex = CurrentSongIndex + 1
  If CurrentSongIndex > Songs.Ubound Then CurrentSongIndex = 0
 
  If CurrentSongIndex <= Songs.Ubound Then
    CurrentSong = Songs(CurrentSongIndex).OpenAsSound
    CurrentSong.Play
    NowPlayingLabel.Text = Songs(CurrentSongIndex).Name
  End If
 
End Sub

Note: Do not type the Sub/End Sub part of the method in the code editor; instead enter that information in the Inspector.

This code stops any currently playing song, increases the current song index by 1 (looping back to the start if the end is reached) and then loads the sound file from the array so it can be played. Lastly it updates the label with the name of the song file.

You can do a quick test with just this code in place. Run the project (using the Remote Debugger) on the Pi and choose a folder containing music files. The first song in the folder should start playing.

Adding Features

There are still two buttons on the window that don’t yet do anything. The Play button will be used to Play and Stop the current song. Add the Action event to the Play button and enter this code:

If CurrentSong.IsPlaying Then
  CurrentSong.Stop
Else
  CurrentSong.Play
End If

The Skip button skips to the next song. Add the Action event and have it call the PlayNextSong method:

PlayNextSong

You can now again run the project on the Pi to test out these new features. When music is playing, click the Play button to stop and play. Click the Skip button to skip to and play the next song.

If you’ve let a song play until it finishes, you’ll notice that the next song does not start playing. This is because there is no code to check if the current song has finished. If you recall the code in the Play button it checks a property called “IsPlaying” to see if the song is currently playing. That property could be also be used by a Timer to check if the song has finished playing so it could start playing the next song. However this won’t quite be enough. If the user manually stops the song, then IsPlaying will be false and the Timer will automatically start playing the next song, which is probably not the behavior you want. To track when a user has manually stopped the music, another property is needed. Add this to Window1:

IsSongStopped As Boolean

Now you can drag a Timer on to Window1 and add the Timer’s Action event handler with this code (you can leave the Timer with its default period of 1000 and Mode to Multiple):

If CurrentSong <> Nil Then
  If Not CurrentSong.IsPlaying And Not IsSongStopped Then
    ' The song is no longer playing and the user has not manually stopped
    ' so that must mean the song has finished on its own.
    PlayNextSong
  End If
End If

And lastly, you need to go back to the Play button Action event handler and change its code to set the value in IsSongStopped like this:

If CurrentSong.IsPlaying Then
  CurrentSong.Stop
  IsSongStopped = True
Else
  CurrentSong.Play
  IsSongStopped = False
End If

Run the project on the Pi and you’ll see that the next song starts playing about 1 second after the current song finishes.

More Raspberry Pi Projects

Are you interested in trying more Raspberry Pi projects with Xojo? Download Xojo for free and then check out the free Programming the Raspberry Pi with Xojo book available on the Xojo Dev Center, which contains this project and many others.

Using the Remote Debugger means that you can now run Xojo apps on the Pi for testing and development without having to first purchase a Xojo license.

We’ve put together a short video to quickly walk you through how to set up and use the Remote Debugger:

For more information about using Raspberry Pi with the Remote Debugger, refer to this topic in the Dev Center:

• Raspberry Pi Remote Debugging

The Raspberry Pi is a complete computer —and a very cheap one!— with USB, HDMI, Ethernet and a GPIO that gives the access to design, create, and control a lot of things (think IoT). The perfect combination to create and deploy complete solutions with Xojo.

Nevertheless, you probably don’t want to use an exclusive display, keyboard and mouse just to control and interact with your Raspberry Pi. What about accessing it remotely via SSH and/or VNC? I bet this is the first thought you had, and here is a step-by-step guide to configure it so you can use your current display, keyboard and mouse from you main computer (the one you use to run the Xojo IDE) to control the Raspberry Pi.

First of all, while you can access your RPi via SSH, displaying your well trained Geek super powers, it is really more convenient to control it via the GUI, as you do your computer. For that you’ll need a VNC client app. There are a lot out there, but VNC Viewer is one that runs just fine and is available for the main platforms. Just download it, run the installer, follow the steps… and you will have completed the first part of the process.

In order to access the Raspberry Pi from the VNC client you will need to know what IP address is using the Pi. How to get that information? Easy! (This assumes that your local network uses DHCP to assign IP addresses, the most common scenario.)

If you use macOS, open the Terminal app (Applications > Terminal) and run the command:

$ ping 192.168.1.255

Changing the ‘192.168.1’ part of the IP address for the one of your local network. What is important here is the ‘255’ number, because this is the Broadcast IP address for your local network.

What happens when we ping the broadcast address? In brief: the packets are sent to every host of the local area so they can respond, giving their IP address in the process. The second piece of the needed information, the MAC Address, is automatically obtained from the hardware interface used by the device to reply the packet request.

Let the ping command do its work for several seconds and break the process pressing Control + C. (If you are using Linux, execute the command as ‘ping -b xxx.xxx.xxx.255‘.

The Mac Address is all the information needed by ARP: the inner cache table used by your router/switch device (and computer too), to link the unique hardware address (MAC Address) used by every device in the network with the IP address used by the device. So, executing the command:

$ arp -a

will give us a complete list of evey active IP address and the linked MAC Address. Knowing what IP addresses are already used by the devices of our network (computers, printers, cell phones, tablets…), it will be easy to identify the IP address assigned by DHCP to the Raspberry Pi.

So with these two pieces of information you can use the DHCP Binding feature of your home switch/router (all the home/SOHO routers have this feature), in order to assign the same IP address to the Raspberry PI every time you turn the device on and, connect it to the network. DHCP Binding looks for the MAC Address of the device… and matches it with the reserved IP address from the DHCP pool.

Starting the VNC Server on the Raspberry Pi

Don’t close the Terminal window yet, there are a couple of things that we need to do first. The first one is starting the VNC Server on the Raspberry Pi, so we can start new remote sessions from our client. For that we need to start an SSH session with:

$ ssh pi@raspberry-pi-address-here

Typing ‘raspberry’ as the password when requested. (‘pi’ and ‘raspbery’ are the user and password configured by default on every Raspberry Pi out there.)

Once started the SSH session, type the following:

pi@raspberrypi:~$ sudo raspi-config

This will open the Configuration Tool. Use the cursor keys to choose the ‘Advanced Options’ entry and press the Return key to advance to a new screen with options. Select the VNC entry (A5) and press the Return key again. Finally, make sure that VNC Server is enabled or enable it if not. Lastly, select the <Finish> option to exit the Configuration Tool.

Adjusting the Display Resolution used by VNC

Great, we have the IP address used by the Raspberry Pi, and the VNC Server enabled so we can start a VNC Client session… just to discover that it shows an endemic resolution of 800 x 600 pixels on our full-fledged Full HD display. Not the most productive thing we can expect.

Time to return to our Terminal windows, where the SSH session is still open (or start a new one if not). This time, we will edit the configuration file to instruct the Raspberry Pi to use a better fixed display resolution. For that, type the command:

pi@raspberrypi:~$ sudo nano /boot/config.txt

Go to the end of the opened file and write these lines:

 hdmi_force_hotplug=1
 hdmi_ignore_edid=0xa5000080
 hdmi_group=2
 hdmi_mode=51

In this case we are telling the Raspberry Pi to use a resolution of 1.600 x 1.200 pixels, but you can choose other changing the ‘hdmi_mode’ option to anyone of the settings you can find in this support page of Raspberry Pi.

Save the changes and exit from the Nano editor, and reboot the Raspberry Pi so the changes take effect:

 pi@raspberrypi:~$ sudo su
 pi@raspberrypi:~$ reboot

Ready! From now on, you can remotely access your Raspberry Pi via VNC and SSH.

You can watch the video (in Spanish only) that talks you though this example.

Javier Rodri­guez has been the Xojo Spanish Evangelist since 2008, he’s also a Developer, Consultant and Trainer who has used Xojo since 1998. He is in charge of AprendeXojo.com and the developer behind the GuancheMOS plug-in for Xojo Developers and the Snippery app, among others.

*Read this post in Spanish

I am pleased to announce some updates to our GPIO project to make it even easier to use more types of hardware in your Raspberry Pi projects.

The Xojo GPIO library, version 1.5 is now available on GitHub and adds support for these hardware features:

• LCD character display
• Servo motor
• RGB LED
• Buzzer tunes

Some of these features were enabled by adding support for the wiringPi SoftPwm and SoftTone methods. In addition, Servo, LCD and RGBLED can be controlled using simple classes.

Head on over to the Xojo Dev Center for tutorials on how to these new features:

• LCD character display
• Controlling a Servo
• Using an RGB LED
• Using a Buzzer

Why work with a simple text editor and the command line when you can instead use a fully-feature IDE to create Raspberry Pi apps for your projects?

Like the rest of the Xojo GPIO library, these new features work similarly to features in commonly used Python GPIO libraries. Now you should be able to readily adapt Python code to work in Xojo so you can more easily create great Raspberry Pi projects!

My Raspberry Pi 2 sits on my desk next to one of my speakers. It’s not hooked up to any display. I use a combination of SSH, SFTP and VNC when I need to work with it.

To connect to the Pi, I just need its IP address, which currently is 10.0.1.11. I leave the Pi on all the time, but if I reboot it then the IP address could change since I have not set it up with a fixed IP address. To identify the IP address, I run the utility LanScan (free on the Mac App Store) which shows me all the IP addresses of everything on my local network. The Raspberry Pi is clearly identified.

I can then connect to the Pi via ssh:

ssh pi@10.0.1.11

I’m prompted for the password, which I’ve left at the default (“raspberry”).

If I am only going to be running Xojo console apps, then this is all I need. You really only need to set up VNC if you want to access the Desktop so you can run Xojo desktop apps (or use the Pi UI to run other desktop apps).

Personally I do like using the Pi desktop, so I now need to start the VNC server, which I have previously installed. If you need to install it, easy VNC installation steps are at the official Raspberry Pi site.

At the ssh terminal, I start VNC using its defaults with this command:

vncserver

After typing this command, I’m back at the terminal prompt. Use the “exit” command to disconnect from the ssh connection.

Now I can connect to the Pi using a VNC client. I’m going to use the client that is built into OS X since it is always available and reasonably fast. In Finder, select Go->Connect to Server from the menu. In the window, enter the address and port for the VNC server and click Connect:

vnc://10.0.1.11:5901

You’ll again be prompted for your password. This is the password you set up when you installed TightVNC, not the Raspberry Pi password.

When everything connects you’ll get a window displaying the Raspberry Pi desktop, shown here running the XojoNotes example app:

But how do you get apps to the Pi so you can run them? I use SFTP. There are many SFTP tools available. I primarily use ForkLift and ExpanDrive, but other apps have also been recommended on the Xojo forum. Regardless of the tool you use, create a new SFTP connection and enter the same credentials you used to connect via ssh.

You’ll now have access to the file system on the Pi and you can drag files from your computer to the Pi’s file system, which will copy them across your network to the Pi. With ExpanDrive, I get a drive mounted to the Finder that is connected to the Pi, making access to the Pi always available.

With your free Xojo Pi license you can develop and build desktop and console Pi apps. Download today and get the latest release!

• A 1.2GHz 64-bit quad-core ARM Cortex-A53 CPU (~10x the performance of Raspberry Pi 1)
• Integrated 802.11n wireless LAN and Bluetooth 4.1
• Complete compatibility with Raspberry Pi 1 and 2

That last bullet point is notable because it means that Xojo is also fully compatible with the new Raspberry Pi 3!

Although the new CPU is 64-bit, it remains fully compatible with the ARMv7 CPU used in the Raspberry Pi 2.

Your 32-bit Xojo apps will continue to work fine in the 32-bit version of Raspbian (the only version available right now) on the Raspberry Pi 3. Once you apply the latest Raspbian updates, you can even just take your SD card from your Raspberry Pi 2 and plug it into a Raspberry Pi 3. To run the updates, just run these commands from the terminal on the Raspberry Pi:

sudo apt-get update
sudo apt-get upgrade

One word of warning, though. Apparently the new Raspberry Pi 3 gives off quite a bit more heat than the Raspberry Pi 2, so you may want to invest in a heat sink or fan for your case.

The Raspberry Pi 3 has the same $35 price as the Raspberry Pi 2. Here are some tutorials to help get you started:

• Blinking LED Tutorial
• Button LED Tutorial
• More Tutorials

If you’ve received yours, let us know how you like it in the comments! Remember you can develop and build console and desktop apps for the Raspberry Pi using Xojo 2019r1 or later for free.

Download Xojo today and get started!

These projects are all free and show you how to hook up a variety of sensors to your Pi and then interface with them using Xojo. Topics include:

• Motion Sensor
• Relay Board
• Flame Sensor
• Humidity and Temperature Sensors
• Infrared Sensor
• Ultrasonic Sensor

These projects make use of the open source GPIO module that is included with Xojo and available on GitHub.

You can view all the Pi Projects here:

Xojo Pi/GPIO Projects

You can develop and build console and desktop apps for the Raspberry Pi using Xojo 2019r1 or later for free.

Download Xojo today and get started!

By default, Raspbian does not include the necessary library to allow the HTMLViewer to work, but you can easily install it. Open a Terminal window on the Pi and enter this command:

 sudo apt-get install libwebkitgtk-1.0.0

This will download and install the library needed by HTMLViewer.

The answer is to use the GPIO module that is included with Xojo in conjunction with the wiringPi library. And now this module is also available on GitHub:

Xojo GPIO Module

This module is used for our two Raspberry Pi projects: Blinking LED and Button LED. They are also used by the Einhugur Pi projects for Xojo.

I encourage all you Raspberry Pi experts to clone the GPIO project on GitHub and push up any enhancements you come up with.

Raspberry Pi is essentially a tiny, inexpensive computer. Because it is tiny, it can be used in all kind of things that a typical computer does not work well with, such as robotics and embedded systems. Since it is also inexpensive, it functions as a great learning tool, making it possible for anyone to have their own computer. Additionally, because a Raspberry Pi is a fully functional computer, with input/output, storage and wifi capabilities, it can also be used to interface and control other things. This makes the Raspberry Pi a favorite amongst tinkerers, Makers, electronics hobbyists and anyone else with a cool idea for a project.

What makes the Raspberry Pi somewhat unique is that it uses an ARM processor (similar to what you see on cell phones and tablets), rather than an Intel CPU that is in most things categorized as “computers”.

Still, a Raspberry Pi is a full computer. You can connect a keyboard, mouse and display to it. You can plug in storage and install an operating system on it (typically Linux). Now, it is not a powerful computer, to be sure, but it is still powerful enough for many tasks.

Although you can program Raspberry Pi, it is not really as easy as it should be. You typically have to deal with scripts, command prompts and other things that make programming less fun. We aim to simplify programming for Raspberry Pi by allowing you to use the simple to learn Xojo IDE and programming language with it.

You can read more about Raspberry Pi, its origins and goals at RaspberryPi.org.

So if you want a Raspberry Pi, how do you get one? There are many places that sell Raspberry Pi and it is available in various configurations and price points. If you want a full kit, that includes everything you need to get started, you can find one at Amazon for about $70 USD. This kit includes the Raspberry Pi itself, a case, power supply, 8GB SD card with OS, USB wifi and cables.

Another common source of Raspberry Pi stuff is Adafruit. There you can buy the bare Raspberry Pi board for $40 or also get lots of other accessories and starter kits.

On the European side of the fence, RobotStore seems to have a lot of Raspberry Pi products.

To learn even more about Raspberry Pi, you might also want to grab MagPi, the free, official magazine of Raspberry Pi. Building for Pi console and desktop is free with a Xojo Pi license in Xojo 2019r1 and beyond!

Or let us walk you through: