Custom 3 Button CircuitPython Keyboard

Introduction

I have been doing audio editing for side project at work. These are long form audio recordings of an hour or more. I am using Adobe Audition to do my editing. After doing several of these, I noticed that I use two main functions frequently.

  1. ‘Silence’
  2. ‘Ripple Cut’ -> ‘ Time Selection in All Tracks’

The ripple cut function either used a significant number of mouse clicks or keyboard shortcuts that required both hands. There are probably a few different potential solutions to this problem. I could have changed the keyboard shortcuts to something else, but I wanted this to be easy to use and I wanted to be able to use it on any computer.

I recently completed a project using that used the PyPortal to send keyboard commands to my computer to open applications. Also, I had purchased an Adafruit Trinket M0 recently and wanted to build a project with it, so I decided to build a mini keyboard that only had a few buttons.

Parts

Schematics

Code

I modified the the Trinket IO Demo code. I removed some stuff that I didn’t need and had to make sure that holding down a key was treated the exact same as a single key press.

Results

The first button is used for play/pause, the second button is used to do the ripple cut and the third button is used to do the silencing. This tool has made it so much easier to edit audio content.

Update – 18 Apirl 201

If you liked this, check out this much more detailed project by Glen Akins (@bikerglen)

Ender 3 – 3D Printer & OctoPrint

Background

I recently purchased a Creality Ender 3 3D printer. I bought this for several reasons:

  1. It is very affordable at $229 on Amazon.
  2. It had a lot of good reviews
  3. Is the Most Popular 3D Printer of Spring 2019
  4. There are lots of upgrades/mods for this printer
    1. 35 Must-Have Creality Ender 3 (Pro) Upgrades & Mods in 2019.

OctoPrint

My interest was peaked when I saw the Raspberry Pi upgrade option under the possible upgrades/mods you could do to the Ender 3.

Let’s face it, we can’t be around to supervise our 3D printer 100 percent of the time. That’s why OctoPrint has become the standard for makers who want to monitor and control their 3D printer remotely. To run this terrific web interface, you need to purchase a Raspberry Pi board.


OctoPrint will allow you to control and observe your Creality Ender 3 from within a web browser. It’s 100 percent open source, which has led to a plethora of unique plugins created by the vast community. On the browser, you can watch prints through an embedded webcam feed, control print temperatures, obtain feedback on current print status, and even start and pause your printer no matter where you are.

35 Must-Have Creality Ender 3 (Pro) Upgrades & Mods in 2019.

I had an extra Raspberry Pi laying around and decided to give it a shot. The software that runs on the Pi is called OctoPrint. Installation and configuration is very straight forward and there are lots of help documents and tutorial videos. I am not going to get into any of the setup in this post, but below is the video that I found most helpful.

How to Install Octoprint on a Creality Ender 3

First Print with OctoPrint

I am currently using a simple USB webcam for the OctoPi. I want to upgrade it to use a mounted Raspberry Pi camera so that it follows the printer head. The video below is a time lapse that was captured using OctoPrint of the mount and case for the Pi camera being 3D printed.

Video 3D print of camera holder for Pi Camera and ender

PyPortal App Launcher

Introduction

PyPortal is a microcontroller that can be programmed using CircuitPython. It has a touchscreen and can be used as a emulate a keyboard and mouse. For this project, we will create a touchscreen with icons that will allow us to launch applications when pressed.

  1. Design: discussions how the touchscreen image and layout are created.
  2. Shortcuts: Create Keyboard Shortcuts to Launch Applications in macOS ( Windows)
  3. Code: CircuitPython code to be added to you PyPortal

The code and design files can be found on Github.

Design

The PyPortal initializes rendering a background image that is .BMP (bitmap image). So I created a template background image that I could insert icons into using Adobe Illustrator. Using this file, I copied and pasted my icons on to the location I wanted and then deleted the while squares underneath.

Icon template file. 3 rows of 4 icons 50×50 pixels. – button-template-12.ai

In order to detect button presses we need to know the boundaries for each icon. The image below shows the pixel length to each border.

Annotated background icon image.

Columns are organized from left to right, from A to D. Rows are organized from top to bottom, from 1 to 3. Please see the below table.

ABCD
1A1B1C1D1
2A2B2C2D2
3A3B3C3D3

We need to know this information in order to determine if an icon is pressed. A touch event returns an (x,y) point with (0,0) being the top left corner. All icons in column B can only be pressed if the x of the touch event is between 97.5 and 147.5. Likewise, all icons in row 1 can only be pressed if the y of the touch event is between 100 and 150. Therefore, if the touch event returns (100,130), then the icon located at B2 has been pressed.

Shortcuts

The easiest way to launch applications using CircuitPython is by sending keyboard commands to your computer. In order to accomplish this on a macOS we need to create these keyboard shortcuts. This is fairly trivial on windows.

  1. Launch Automator on your mac
  2. Create a new “Quick Action”
    1. File -> New -> “Quick Action” -> Choose
  3. Under actions search for “Launch Application”
  4. Drag “Launch Application” into the window
  5. From the drop down list select the application that you want to open
  6. Switch the “Workflow Receives” drop down to “no input”
  7. Save your quick action
    1. Either CONTROL+S or File -> Save
  8. Close Automator
  9. Create the keyboard shortcut to activate the “Quick Action” you created
    1. Go to Settings -> Keyboard
    2. Click on the Shortcuts tab
    3. Select Services
    4. Scroll to the General section near the bottom.
    5. Highlight the “Quick Action” you created and click the Add Shortcut button.
    6. Press the keyboard keys that you want to set the shortcut to.
    7. I used “ALT+CONTROL+SHIFT+COMMAND+[FIRST LETTER OF APP]” for each of my shortcuts. I did this because I knew there would be no other shortcuts using this combination.

Code

The code has comments throughout and they should explain everything. If you have questions please feel free to email me or DM me on twitter. You will need to copy the below code as code.py in the root of your PyPortal as well as you BMP icon file. Please update the below code with your keyboard shortcuts and the name of your BMP icon file.

MAME Bar Top Aracade Cabinet

Introduction

Update: Check out this Instructable –Legend of Zelda Bartop Arcade Cabinet

In an old episode on Hak5, Wess Tobler (@Dankiswess) did segment on making a MAME bar top arcade cabinet. This segment inspired me to make my own MAME (Multiple Arcade Machine Emulator) arcade cabinet, so I began doing research on different MAME cabinet designs. Bartop Arcade had many different designs and templates for bar top arcades. Below is the design and template that I based my MAME cabinet off of.

Build Phase

Items need for the build phase:

For the build phase I used the template that I found from Bartop Arcade and cut out each piece. I decided against having a slide out drawer, so I had to make some slight modifications. Below is a picture of the cabinet about 90% into the build phase.

After cutting and assembling the exterior of the cabinet, I had to wire all the buttons. Once that was done it was onto the software configuration.

Software Configuration

A lot of research went into deciding exactly how the software side of this project would be configured. I was initially set on using MALA as my front-end, but then I found Hyperspin.

Not only was Hyperspin a superior looking front-end, it would allow me to run many different emulators including a NES and SNES emulator. Hyperspin does most of its configuration through GUIs and XML files. Below is a image of the cabinet 90% complete running PAC-MAN.

Hyperspin also allowed for configuring other applications to open from within it. I configured it to run Aussie Juke as one of the emulators. Also, after reading a comment by Moonlit on episode five of TheNewTech.tv, I decided to modify the registry entry for explorer.exe to boot to Hyperspin.
HKEY_Current_User\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell

Final Thoughts

There are several things I have to do to complete this project. First, I need to finish the marquee. The marquee will end up being a cylon eye covered by a tinted plexiglass. Second, I need to mount the pc hardware inside the cabinet. I currently have it connected to PC tower.