Freeform Clock
This project was both an experiment and exercise in making something with parts I already had. It uses an STM32 and one red LED that tells the time in morse code.
Even though it works as intended, it's not at all reliable as a clock. Due to the time consumption of soldering everything in awkward positions, I skipped adding an external 32.768kHz crystal that would ensure the RTC is accurate. During testing, I observed the duration of “one minute” is roughly 50 seconds.
The inspiration for this came from examples of freeform circuits that intrigued me, specifically the works of Eirik Brandal and Mohit Bhoite.
This is the first one I've made, so it's a bit rough.
- Microcontroller
- STM32
- Display
- One red LED, morse code
- Regulator
- 3.3V voltage regulator
- Power
- 5V DC power supply (center positive)
- Structure
- K & S Precision Metals brass rods
- Programming
- SWD
01
Setting Time
The only method to set the time is to plug the clock in at midnight. When powered on, the RTC starts at 00:00 in 24 hour time format. There is no way to set the time once plugged in.
02
Programming
It is programmable via SWD and some alligator clips. I positioned several rods far out enough to be able to carefully connect to and program the STM32. While this does work, it's quite delicate and very easy to accidentally bend a rod out of place. Best not to do this often.
03
Core Components
- STM32
- 3.3V voltage regulator
- DC Jack
- All necessary decoupling capacitors/etc that would be used in a practical PCB.
- Red LED
- 5V DC power supply (center positive)
Everything is soldered together using K & S Precision Metals brass rods. A few different sizes were used. The smallest size used was 0.51mm, which was for soldering directly to the pins of the STM32, as well as other small components. 0.81mm and 1.5mm were used for power and ground rails, as well as a rigid structure.