Gikfun 4-Digit LED Electronic Alarm Clock DIY Kit EK1985-US Instruction Manual

1. Introduction

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. Safety Information

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.
• Work in a well-ventilated area to avoid inhaling solder fumes.
• Ensure your soldering iron is on a heat-resistant stand and unplugged when not in use.
• Avoid touching the hot tip of the soldering iron.
• Keep a fire extinguisher or water nearby in case of accidental fire.
• Handle electronic components carefully to prevent damage from static electricity.
• Keep small components out of reach of children.

3. Package Contents

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.

Figure 2: Overview of the Gikfun EK1985-US DIY kit components and assembly steps.

3.1 Tools Needed (Not Included)

• Soldering iron
• Solder wire
• Wire cutters
• Tweezers
• Multimeter (for checking component values)
• Small screwdriver

3.2 Component List

4. Assembly Instructions

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.

1. 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.
2. Install Crystal Oscillator: Solder the crystal oscillator (32.768KHz) into its designated position on the circuit board.
3. 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).
4. Install Battery Holder: Solder the battery shrapnel (CR1220 battery holder) onto the board. Ensure correct orientation if applicable.
5. 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.
6. Install IC Sockets: 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.
7. Install Transistor: Solder the S8550 transistor. Align the semi-circular shape of the transistor with the semi-circular graphic on the board.
8. Install Tactile Switches and DC Socket: Solder the two tactile switches (UP and SET) and the DC005 power socket onto the board.
9. 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.
10. Weld Digital Tube Pins: Solder the pins of the 4-digit LED display onto the circuit board. Ensure all pins are securely connected.
11. Install ICs: 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.
12. 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.
13. Secure 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. Circuit Diagram

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. Operating Instructions

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 Display Modes

The clock cycles through different display modes automatically:

• Time Display: Shows the current time (e.g., 12:30). Includes PM indicator for 12-hour format.
• Date Display: Shows the current date (year, month, day, week).
• Temperature Display: Shows the ambient temperature in real-time.

6.2 Setting Time and Date

1. Press the SET button once to enter time setting mode. The hour digits will flash.
2. Use the UP button to adjust the hour.
3. Press SET again to move to minute setting. Use UP to adjust minutes.
4. Continue pressing SET to cycle through setting year, month, day, and week, adjusting each with the UP button.
5. After setting the week, press SET one more time to exit setting mode and save changes.

6.3 Alarm Clock Function

The clock includes an alarm function with four adjustable music options.

1. To set the alarm, press and hold the SET button for approximately 3 seconds. The alarm hour digits will flash.
2. Use the UP button to adjust the alarm hour.
3. Press SET again to move to alarm minute setting. Use UP to adjust minutes.
4. Press SET again to select the alarm music (1-4). Use UP to cycle through music options.
5. Press SET one more time to exit alarm setting mode.
6. 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 Brightness Adjustment

The clock features both automatic and manual brightness adjustment.

• Automatic Adjustment: The built-in photoresistor (light sensor) automatically adjusts the display brightness based on ambient light conditions.
• Manual Adjustment: While in normal time display mode, a short press of the SET button (not held) will cycle through manual brightness levels.

6.5 Temperature Calibration

For the first use, or if temperature readings appear inaccurate, calibration may be necessary.

1. Enter temperature display mode (the clock cycles to it automatically).
2. Press and hold both UP and SET buttons simultaneously for approximately 3 seconds to enter temperature calibration mode. The temperature display will flash.
3. Use the UP button to adjust the temperature offset. Compare with a known accurate thermometer.
4. Press SET to save the calibration and exit the mode.

7. Specifications

• Model: EK1985-US
• Display: 4-Digit LED
• Functions: Time (12/24-hour), Date (Year, Month, Day, Week), Temperature, Alarm Clock with 4 melodies, Power-off memory.
• Brightness: Automatic adjustment via photoresistor, manual adjustment.
• Power Supply: 5V DC (via USB cable)
• Backup Battery: CR1220 (for time memory during power loss)
• Dimensions (Assembled): Approximately 11.5 cm (4.52 in) x 4 cm (1.57 in) x 3.2 cm (1.25 in)
• Manufacturer: Gikfun

8. Troubleshooting

• Clock does not power on:
  • Ensure the 5V DC power supply is connected correctly and functioning.
  • Check all solder joints for cold joints or bridges.
  • 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.
• Temperature reading is inaccurate:
  • Ensure the thermistor is correctly soldered and not damaged.
  • Perform temperature calibration as described in the operating instructions.
• Display is too dim or too bright:
  • 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.
• Buttons are unresponsive:
  • Verify the tactile switches are correctly soldered and not shorted.
  • Ensure the MCU (STC8G1K17) is correctly inserted and oriented.
• Alarm does not sound:
  • 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. Warranty and 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.