makeTVee-
Software
05/10/2025 at 12:06 • 0 commentsThe code is running on a XIAO nRF52840 Sense board using Zephyr RTOS (VS Code with nRF-Connect). It is my first Zephyr project, so still learning.
- Peripherals:
- Addressable LEDs (4x35) as one strip
- 5 different countdown animations
- Accelerometer for hour glass trigger
- Servo (PWM)
- (Microphone for future use)
The LED animations are running in the main thread, the Servo control and timing for the alarm mechanism is in a separate thread triggered when the 1 minute is left.
Sourcecode: https://gitlab.com/maketvee/ltt_zephyr
I used some pixel art tools to test animations and also generated tome GIFs for my Lightning talk about the timer at HdE.
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Alarm mechanism
05/10/2025 at 12:06 • 0 commentsThe alarm mechanism was designed to be triggered once per countdown. A steel ball sits in an upper compartment and falls down as soon as the slider is moved by the servo. The ball hits an old phon bell in the middle of the mechanism and falls down into the lower compartment. The compartments are now closed again. When the clock is flipped for restarting the countdown, the ball is also flipped and now the lower compartment is the upper compartment. So flipping the timer is also rearming the timer, and no additional energy is needed to move the ball, just gravity.
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The servo is triggerd at startup and 1 minute before the countdown ends. All parts are custom designed and 3D printed.![]()
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5x7 LED panel
05/10/2025 at 11:50 • 0 commentsThe 5x7 LED panel PCB was designed in KiCAD with 5050 WS2812B LEDs
The PCB is mounted at the back of a 3D printed diffuser using two layers of white PLA as a diffuser.
The pixels are separated with black PLA. Printing is done with color change, so the outer layer is one closed surface.
After some first fails, the white PLA was interweaved into the black PLA by enlarging the second layer. This leads to a robust solution and the white PLA stays in place even when pushing on it directly with the finger.
Lightning Talk Timer
LED Countdown timer for short talks with hour glass trigger. Built for Hackaday Europe 2025.
The PCB is mounted at the back of a 3D printed diffuser using two layers of white PLA as a diffuser.
The pixels are separated with black PLA. Printing is done with color change, so the outer layer is one closed surface.
After some first fails, the white PLA was interweaved into the black PLA by enlarging the second layer. This leads to a robust solution and the white PLA stays in place even when pushing on it directly with the finger.