Review on ⏰ DAOKI DIY Kit Module - Digital LED Electronic Clock Components (9V-12V AT89C2051) by Steve Waldbillig

Good set, quite simple design. The part numbers are marked on the circuit board to make it easier. I only have a few problems. 3mm LEDs have a wide range of brightness. It's a bit tricky to program and you just have to switch with one button if you miss it. Also, there is (it seems) no secondary set or reset function, and the seconds are counted once power is applied and during programming, so this can be a little inaccurate. When using the reference clock you can increase the accuracy in seconds by applying mains power when the reference clock reads 00s and then adding a 3V coin cell battery. Finally, the CR2032 cell is not included. Tips: You will need 3 jumpers made from leftover wire cut from components. I suggest diode lines as they are the thickest and longest. Don't forget to add the jumper under the LED indicator first, it will be a big problem if you forget the indicator and then solder it. You will also need a power supply, you can use a 9V battery and clip or 4 AAA/AA cells. and holder. Or any other DC 5-12V source. My board uses a 5V regulator so 6V plus is recommended, although I've seen some reviews mentioning that 3xAAA/AA (4.5V) will work, for stability you need to have an input that at least 1V higher than the voltage regulator. Finally, you will need a 3V CR2032 lithium coin cell battery. The longest lead on 3mm LEDs is the + terminal. Pay close attention to polarity or LEDs. One of the four LEDs is inserted opposite the others.