1. Einleitung
This manual provides detailed instructions for assembling and operating the Gikfun EK1985-US 4-Digit LED Electronic Alarm Clock DIY Kit. This kit is designed as a soldering practice and learning project, allowing users to build a functional digital clock that displays time, date, and temperature, with alarm and brightness adjustment features.

Figure 1: The fully assembled Gikfun 4-Digit LED Electronic Alarm Clock.
2. Sicherheitshinweise
Please read and understand all safety precautions before beginning assembly. This kit involves soldering, which requires careful handling of hot tools and electronic components.
- Always wear appropriate personal protective equipment, including safety glasses, when soldering.
- Arbeiten Sie in einem gut belüfteten Bereich, um das Einatmen von Lötrauch zu vermeiden.
- Ensure your soldering iron is on a heat-resistant stand and unplugged when not in use.
- Vermeiden Sie es, die heiße Spitze des Lötkolbens zu berühren.
- Keep a fire extinguisher or water nearby in case of accidental fire.
- Handle electronic components carefully to prevent damage from static electricity.
- Bewahren Sie Kleinteile außerhalb der Reichweite von Kindern auf.
3. Packungsinhalt
Before starting assembly, verify that all components listed below are present in your kit. Refer to Figure 2 for a visual representation of the kit components and assembly steps.

Abbildung 2: Überview of the Gikfun EK1985-US DIY kit components and assembly steps.
3.1 Tools Needed (Not Included)
- Lötkolben
- Lötdraht
- Drahtschneider
- Pinzette
- Multimeter (for checking component values)
- Kleiner Schraubendreher
3.2 Komponentenliste
| NEIN. | Komponentenname | Modell | Menge |
|---|---|---|---|
| 1 | Widerstände | 10 | 4 |
| 2 | NTC-Thermistor | 10 | 1 |
| 3 | Fotowiderstand | 5 MM | 1 |
| 4 | Quarzoszillator | 32.768 kHz | 1 |
| 5 | Transistor | Staffel 8550 | 1 |
| 6 | Tastschalter | 6x6x10mm | 2 |
| 7 | DC-Buchse | DC005 | 1 |
| 8 | Summer | 8.5 x 12 mm | 1 |
| 9 | Batteriesplitter | 1220 | 1 |
| 10 | Kondensatoren | 22pF | 2 |
| 11 | Kondensatoren | 10uF | 2 |
| 12 | IC-Buchse | 16-polig | 2 |
| 13 | IC (Real-Time Clock) | DS1302 | 1 |
| 14 | IC (Microcontroller) | STC8G1K17 | 1 |
| 15 | 4-stellige LED-Anzeige | 1 | |
| 16 | Acrylschale | 1 Satz | |
| 17 | USB-Stromkabel | 1 | |
| 18 | CR1220 Knopfzelle | CR1220 | 1 |
| 19 | Schrauben | 4 |
4. Montageanleitung
Follow these steps carefully to assemble your Gikfun 4-Digit LED Electronic Alarm Clock. Refer to Figure 2 for visual guidance during each step, and Figure 3 for detailed component identification.
- Pre-check Components: Before soldering, check all part values and quantities against the component list. Use a multimeter to verify resistor values. Note that 10K resistors have no distinction between positive and negative poles.
- Install Crystal Oscillator: Solder the crystal oscillator (32.768KHz) into its designated position on the circuit board.
- Install Capacitors: Solder the two 22pF capacitors and the two 10uF capacitors. These components typically have no polarity unless marked otherwise (for electrolytic capacitors like 10uF, ensure correct polarity if present).
- Batteriehalter einbauen: Solder the battery shrapnel (CR1220 battery holder) onto the board. Ensure correct orientation if applicable.
- Install Buzzer: Solder the buzzer onto the circuit board. Pay attention to the positive (+) and negative (-) markings on the board and the buzzer for correct orientation.
- IC-Sockel installieren: Solder the two 16-pin IC sockets onto the board. Pay attention to the notch or dot on each socket, aligning it with the corresponding marking on the circuit board.
- Install Transistor: Solder the S8550 transistor. Align the semi-circular shape of the transistor with the semi-circular graphic on the board.
- Install Tactile Switches and DC Socket: Solder the two tactile switches (UP and SET) and the DC005 power socket onto the board.
- Install Photoresistor and Thermistor: Solder the photoresistor and thermistor. Leave a 1cm gap between the components and the circuit board during installation to allow for proper function and adjustment.
- Weld Digital Tube Pins: Solder the pins of the 4-digit LED display onto the circuit board. Ensure all pins are securely connected.
- ICs installieren: Carefully insert the DS1302 IC and the STC8G1K17 MCU into their respective sockets. Ensure the notch or dot on each IC aligns with the notch on its socket and the marking on the board.
- Install Circuit Board into Casing: Place the assembled circuit board into the acrylic shell. Connect the photoresistor and thermistor to their designated positions within the casing.
- Sicheres Casing: Secure the acrylic casing with the provided screws. Tighten them gently to avoid cracking the acrylic.


Figure 3: Left: Detailed view of the circuit board with key components labeled. Right: External view of the clock with dimensions and labeled sensors/power input.
5. Schaltplan
For advanced users or troubleshooting, the circuit diagram provides a detailed schematic of the Gikfun EK1985-US clock. This diagram illustrates the connections between the microcontroller (MCU), real-time clock (DS1302), LED display, sensors, and input buttons.

Figure 4: Complete circuit diagram for the Gikfun EK1985-US electronic clock.
6. Bedienungsanleitung
Once assembled, connect the clock to a 5V DC power supply using the provided USB cable. The clock will power on and display the current time. The clock features two setting switches: "UP" and "SET" (refer to Figure 3, right image, for location).
6.1 Anzeigemodi
The clock cycles through different display modes automatically:
- Zeitanzeige: Shows the current time (e.g., 12:30). Includes PM indicator for 12-hour format.
- Datumsanzeige: Shows the current date (year, month, day, week).
- Temperaturanzeige: Shows the ambient temperature in real-time.
6.2 Uhrzeit und Datum einstellen
- Drücken Sie die SATZ Durch einmaliges Drücken der Taste gelangen Sie in den Zeiteinstellungsmodus. Die Stundenziffern blinken.
- Verwenden Sie die UP Taste, um die Stunde einzustellen.
- Drücken SATZ again to move to minute setting. Use UP um die Minuten einzustellen.
- Drücken Sie weiter SATZ to cycle through setting year, month, day, and week, adjusting each with the UP Taste.
- After setting the week, press SATZ one more time to exit setting mode and save changes.
6.3 Weckerfunktion
The clock includes an alarm function with four adjustable music options.
- Zum Einstellen des Weckers die Taste gedrückt halten SATZ Die Taste etwa 3 Sekunden lang gedrückt halten. Die Ziffern der Weckzeit blinken.
- Verwenden Sie die UP Taste, um die Weckzeit einzustellen.
- Drücken SATZ again to move to alarm minute setting. Use UP um die Minuten einzustellen.
- Drücken SATZ again to select the alarm music (1-4). Use UP to cycle through music options.
- Drücken SATZ Ein letztes Mal, um den Alarmeinstellungsmodus zu verlassen.
- To turn the alarm on or off, a quick press of the UP button (outside of setting mode) will toggle the alarm status. An indicator on the display may show if the alarm is active.
6.4 Helligkeitseinstellung
The clock features both automatic and manual brightness adjustment.
- Automatische Anpassung: The built-in photoresistor (light sensor) automatically adjusts the display brightness based on ambient light conditions.
- Manuelle Einstellung: While in normal time display mode, a short press of the SATZ button (not held) will cycle through manual brightness levels.
6.5 Temperaturkalibrierung
For the first use, or if temperature readings appear inaccurate, calibration may be necessary.
- Enter temperature display mode (the clock cycles to it automatically).
- Drücken und halten Sie beide UP Und SATZ buttons simultaneously for approximately 3 seconds to enter temperature calibration mode. The temperature display will flash.
- Verwenden Sie die UP button to adjust the temperature offset. Compare with a known accurate thermometer.
- Drücken SATZ to save the calibration and exit the mode.
7. Spezifikationen
- Modell: EK1985-US
- Anzeige: 4-stellige LED
- Funktionen: Time (12/24-hour), Date (Year, Month, Day, Week), Temperature, Alarm Clock with 4 melodies, Power-off memory.
- Helligkeit: Automatic adjustment via photoresistor, manual adjustment.
- Stromversorgung: 5V DC (via USB cable)
- Backup-Batterie: CR1220 (for time memory during power loss)
- Abmessungen (montiert): Ungefähr 11.5 cm (4.52 Zoll) x 4 cm (1.57 Zoll) x 3.2 cm (1.25 Zoll)
- Hersteller: Gikfun
8. Fehlerbehebung
- Clock does not power on:
- Ensure the 5V DC power supply is connected correctly and functioning.
- Prüfen Sie alle Lötstellen auf kalte Lötstellen oder Lötbrücken.
- Verify the DC socket is properly soldered.
- Incorrect time/date display:
- Ensure the DS1302 IC is correctly inserted into its socket and oriented properly.
- Verify the crystal oscillator is correctly soldered.
- Check the CR1220 button battery for proper installation and charge. A missing or dead battery can affect timekeeping during power outages.
- Follow the operating instructions to set the time and date accurately.
- Die Temperaturanzeige ist ungenau:
- Ensure the thermistor is correctly soldered and not damaged.
- Perform temperature calibration as described in the operating instructions.
- Das Display ist zu dunkel oder zu hell:
- Check the photoresistor for correct soldering and ensure it is not obstructed.
- Adjust brightness manually using the SET button as described in the operating instructions.
- Tasten reagieren nicht:
- Verify the tactile switches are correctly soldered and not shorted.
- Ensure the MCU (STC8G1K17) is correctly inserted and oriented.
- Der Alarm ertönt nicht:
- Ensure the buzzer is correctly soldered with the correct polarity.
- Verify the alarm is enabled (check display indicator) and set to the correct time.
9. Garantie und Support
This Gikfun DIY kit is intended as a learning project. Due to the nature of DIY assembly and soldering, specific warranties may vary. For technical support, component inquiries, or further assistance, please contact Gikfun directly through their official channels or the retailer where the product was purchased.
For more information about Gikfun products, visit the official Gikfun store: Gikfun Store on Amazon.