Introduction

I had a thermal printer for a while now, but never used it as part of a project. Recently, I purchased the new Raspberry Pi Touch Screen and decided to make a kind of photo booth. The touch screen would be used for the user input, instead of using (mechanical) buttons. If the user is satisfied with the picture, it can be printed on the spot by the small printer.

It's certainly not a new idea, but I thought it would be a fun little project to try out.

The main components used in this project are:

Raspberry Pi

For this project, I ended up using a Pi 2. Originally, I tried with the A+, but some software components failed to install (more on that in the "Kivy" paragraph).

For the OS, the latest version of Raspbian was used (2015-09-24 Jessie). It can be downloaded from the official Raspberry Pi website: https://www.raspberrypi.org/downloads/raspbian/

Getting the OS image on a microSD card can be done in several ways depending on your own operating system. In my case, in OSX, I used "dd" to get the image on the micro SD card.

Fredericks-Mac-mini:~ frederickvandenbosch$ sudo diskUtil list
Fredericks-Mac-mini:~ frederickvandenbosch$ sudo diskUtil unmountDisk /dev/diskX
Fredericks-Mac-mini:~ frederickvandenbosch$ sudo dd if=Downloads/2015-09-24-raspbian-jessie.img of=/dev/diskX bs=1m
Fredericks-Mac-mini:~ frederickvandenbosch$ sudo diskUtil unmountDisk /dev/diskX
                     

Once the image has been written to the microSD card and the card has been unmounted, it can be removed from the PC and inserted in the Raspberry Pi.

Touch Screen

Connecting and getting the touch screen to work with the Raspberry Pi was super easy using the instructions found right here on element14: http://www.element14.com/community/docs/DOC-78156#installI

Using the latest Raspbian image (2015-09-24 Jessie), the touch screen was plug & play. I did install the additional virtual keyboard by executing following command:

pi@photobooth ~ $ sudo apt-get install matchbox-keyboard
                        

WiPi

Getting wifi to work on the Pi is another one of those plug & play things. Just connect the wifi dongle, select the access point you wish to connect to in the desktop environment and enter the password. That's all there is to it.

Pi Camera

No photo booth without a camera, right? Let's see how to connect and enable the camera.

Connecting the camera

To connect the camera to the Pi, open the CSI slot located near the ethernet port and ensure the camera's flex cable is inserted with the exposed contacts facing away from the ethernet port.

Enabling camera support

By default, the camera support is disabled. To get the camera to work, support needs to be enabled using the "raspi-config" tool.

Open a terminal and enter following command:

pi@photobooth ~ $ sudo raspi-config
                      

A menu will appear. Select option 5: "Enable Camera", and in the following step, select "Enable". Reboot the Pi.

Thermal Printer

To set up the printer, a complete guide is available over at Adafruit (https://learn.adafruit.com/pi-thermal-printer/overview), only a few steps are relevant for this project though and I will highlight them in the next paragraphs.

Connecting the printer

There are two parts to connect the printer:

• power, using an external 5V power supply (at least 1.5A for the printer only)
• data, using the Pi's GPIO serial interface (including GND)

To easily connect an external power supply, I cut off one end of the provided power cable and screwed on a female DC barrel jack connector. The data cable, even though not ideal, can be connected to the Raspberry Pi's GPIO. Careful though, the the printer's TX pin (RX on the Pi's GPIO) should either be disconnected or have a 10k resistor added to compensate for the level difference (5.0V vs 3.3V).

You'll notice I moved the GND jumper wire from the touch screen to another GND pin, in order to accommodate the printer's data cable.

Controlling the printer

Start by installing the necessary software components.

pi@photobooth ~ $ sudo apt-get install python-serial python-imaging python-unidecode
      

In the cmdline.txt file, remove references to ttyAMA0 to avoid conflicts with the printer on the serial interface.

pi@photobooth ~ $ sudo nano /boot/cmdline.txt

#dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait
dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait

Download the Adafruit python library for the printer, containing some example code.

pi@photobooth ~ $ sudo apt-get install git
pi@photobooth ~ $ git clone https://github.com/adafruit/Python-Thermal-Printer
pi@photobooth ~ $ sudo reboot
                   

After the Pi has rebooted, it should be possible to make a test print.

pi@raspberrypi ~ $ cd Python-Thermal-Printer
pi@raspberrypi ~/Python-Thermal-Printer $ python printertest.py
                   

The printer should then output something like this:

Kivy

Kivy is an open source Python library used for developing applications making use of user interfaces. Kivy's official website can be found here: http://kivy.org/#home

The installation steps and some example code are provided via Matt Richardson's tutorial, in which he used Kivy to control the Pi's GPIO using the touch screen: http://mattrichardson.com/kivy-gpio-raspberry-pi-touch/index.html

Some notes on my experience, performing the installation:

• I originally used the Raspberry Pi A+. However during the Cython installation step, it runs out of memory and starts swapping. The installation never finishes as the kswapd0 process takes 100% CPU. Using the Raspberry Pi 2, no problems were encountered.
• Originally, when trying to edit the Kivy's config.ini (~/.kivy/config.ini) in order to add touch support, the file didn't exist. After running an example (~/kivy/examples/demo/pictures/main.py), the file was there and could be edited.

Project

With all individual components working, it's time to move on to the project specific topics.

Code

The code is based on Matt Richardson's example application, which was then adapted to suit my needs. In addition, Adafruit's thermal printing python library was added to have printing support as well.

I've added comments in the code to make easier to understand.

Build

For the frame, I picked something simple: a wooden board holding all the components in place. The result would be a flat and portable photo "booth".

I started by using some tape to draw on and see how the result would be. Everything looked good, so I started cutting and drilling. A bit of sanding was required to make everything fit.

Demo

You don't have permission to edit metadata of this video.

Edit media

Dimensions x Small Medium Large Custom

Subject (required) Brief Description Tags (separated by comma) Video visibility in search results Visible Hidden

Parent content

Raspberry Pi Photo Booth (with Touch screen & Thermal printer)

Poster

Upload Preview

Ok

Cancel

Hope you like the project!