The Wedge - Friendly Focus Companion

I previously built and used the lovely IGOR timer by Urban Circles.   Starting from similar electrical components, I built a new pomodoro timer with a very different aesthetic. 

The components are backwards compatible with the code from Urban Circles.  Because of the slightly different components being used, the build/assembly instructions are somewhat different.

Description

Being based on the same code, the timer shares the main functions of IGOR, with the addition of a sleep function in the menu and some code improvements.

• Up and Down Counting Modes
• OLED Display
• Manual Timer Reset
• Scroll wheels that are interchangeable

BOM

I've included estimated costs, but obviously this will vary based on supplier and how many are purchased.  Total cost for the build is less than $20 including filament cost.  Links are provided for the components I used, but I encourage you to source locally or explore other processor options.  The build instructions may vary if you use other components, but you'll learn a lot along the way.

Printing and Build Instructions

Print Settings:

• 0.1 layer height
  • Larger layer heights should work, but the gears and dial shaft will work the best at 0.1
• 10% infill
• 2 walls
• Support only needed for the main body piece
• I add a brim on most of my prints to prevent warping and peeling.  The body and dial shaft in particular have very small contact patches and may require a brim.

Align the Parts Printed Parts:

All of the items can fit on one build plate (a1 mini plate pictured):

Assemble and Test the Electronics

Here's the wiring diagram from the original IGOR project.  It is pin for pin compatible.

Use the breadboard wires to connect between the various headers and tie all the ground and voltage lines together.  This will likely involve some light soldering to attach the breadboard header pins to the board.  After everything is wired up, connect a USB charging cable to the USB connector on the D1 board.  I recommend that you NOT connect the freshly wired board to your computer until you test with a stand-alone charging cable to make sure you don't let out the smoke.  If the board doesn't produce the magic smoke after a few minutes of being plugged into the USB charging cable, you have some reassurance that you won't harm your computer. Move the USB cable from the wall charger to your computer.  When you plug the USB-C cable into the D1, you should see a short flash on the D1's indicator LED.

Program the D1 ESP

Here is where some differences in how the Wedge is assembled start to emerge.  This may vary depending on what kind of D1 ESP chip you get.  The flow that was easiest for me was using the online Arduino IDE.  There are many good options for writing your program to the chip and I encourage you to use whatever works best for you. 

With the D1 connected to your computer with the USB-C cable:

• Sign in or create an account at https://app.arduino.cc/
• Download the program or “sketch” for the D1 from UrbanCircles
• Navigate to the “Sketches” area at the top left and create a new imported sketch
• 
• Upload the sketch you downloaded in step #2 into the Arduino cloud IDE
• If you're using the same chips I've linked above, you want to select the “LOLIN(WEMOS) D1 mini Lite” type of chip.
• Use the checkmark button to make sure the code you've uploaded works - it should work without modifications. The console will display a green message indicating success.
  • 
  • 
• Use the arrow button to write your program to the D1 chip.  You should see another green message indicating the upload was successful. 
  • 
  • 

At this point you should see the OLED display activate.  Turning the POT should move you through the menu. Pressing down on the POT shaft will select a menu item.  If all of this is working properly, you can move on to assembling the electronics into the 3D printed body.

Assemble the Components into the Body

Getting all of the components into the body can be somewhat tricky. There are a lot of wires and the body itself is fairly compact.  Having built my own during development 20-30 times, I can reassure you that it is all very easy once you understand how the pieces go together. In summary, you should assemble things in this order:

• Build the scroll wheel mechanism
  • Insert the pot through the bottom of the scroll wheel frame
    • Ensure the long side of the POT board is facing towards the flat side of the frame.  If it faces the wrong way, you won't be able to insert the frame into the body in the next steps.
    • No retaining nut is needed, the clips hold the board in place
  • Slide the POT gear on top of the pot shaft. the POT gear is keyed and should slide on snuggly
  • slide the scoll wheel shaft through the front of the frame, over the top of the POT gear and through the scroll wheel.
  • At this point you should be able to test:
    • the scroll wheel rotates easily
    • depressing the scroll wheel also activates the click action on the POT
• Insert the OLED screen into the retaining clips
• Insert the scroll wheel mechanism into the body
• Insert the D1 into the retaining clips on the bottom door
• Snap the bottom door onto the body.

Success!

If this is your first electronics project of this type, congratulations!  Each of these steps can be confusing the first time.  There are a few combined disciplines that go into building this device, but it is quite straightforward once you understand the process.  I am confident that anyone can build this project given the right amount of determination and patience. 

You now have your very own pomodoro timer that should help you concentrate and focus on your next task. I'm using mine right now to build these instructions.

Versions

• V1.1 - I pushed a new version of the bottom door with an ESP mount that holds the ESP more securely.
• V1 - Initial version