niklauslee / cooking-timer

A cooking timer made with 7-segment LED, knob and buzzer

Overview

A cooking timer made with Raspberry Pi Pico, a 7-segment LED display (TM1634), a rotary encoder, and an active buzzer.

Components

Part	Quantity	Note
Raspberry Pi Pico	1
TM1634	1	4-digits 7-segment
Rotary Encoder	1	with push button
Active Buzzer	1
3D printed case	3 pieces
Slide switch	1
2xAAA Battery holder	1
M2x5 crews	11
Perfboard	1	3cm x 7cm
Rare-earth magnets	8	diameter 3mm, thickness 3mm

Wiring

I first made a prototype on a breadboard and then wiring parts on a perfboard.

Pico	TM1634	Encoder	Buzzer	Battery	Switch
VSYS					P
				+	O
3V3	VCC	VCC (+)	VCC
GND	GND	GND	GND	-
GP0	CLK
GP1	DIO
GP2		CLK
GP3		DT
GP4		SW
GP5			IO

Assembly

I made a 3D model for the case with Tinkercad and then print it with FDM-type 3D printer (Ender 5). Here is the link of the model.

• Tinkercad: https://www.tinkercad.com/things/i0qbI05kQMx

After the case printing, the magnets should be inserted into the 8 holes. Pay attention to the insertion direction of the magnets so that the two case pieces can be stick well.

Then mount 7-segment display, active buzzer, and perfboard into the case body with screws. The rotary encoder should be mounted with a nut in the top hole and the battery holder and the slide switch should be mounted on the case back cover. Before mounting the Pico, the code should be uploaded.

Lastly the rotary encoder should be inserted into the 3D-printed top handle.

Usage

Set time by turning the encoder (increate in clockwise, decrease in anti-clockwise). To start the timer press the encoder. When timer get to zero, the buzzer will generate beep sound.

In default 30 seconds is the step of the encoder. You can change by set step variable in the code.

See also

• TM1637
• Rotary Encoder
• Active Buzzer