Review on 🌈 Enhance Your Arduino and Raspberry Pi Projects with KOOKYE Lilypad LEDs (25x Lilypad LED) in Red/Yellow/White/Blue/Green Variants by Daniel Bruce

They attach but tear very easily. Nice little design with big enough pads for easy soldering. They have a built in 150 ohm resistor (R) so they can be connected directly to a voltage source. The color is nice, they are very bright. Here are the specs/specs of each. ), Forward Voltage (VF) 2.0 to 2.4 V Blue - Forward Current 20 mA (IF), Forward Voltage (VF) 3.2 to 3.8 V Yellow - Forward Current 20 mA (IF), Forward Voltage (VF) 2, 0 to 2.4VWhite - Forward Current 30mA (IF), Forward Voltage (VF) 3.3 to 4.0V Green - Forward Current 20mA (IF), Forward Voltage (VF) 3.2 to 3.8V Based on From the specifications above, the voltage ranges to achieve IF are shown below. Voltages below the recommended voltage are acceptable, but exceeding the recommended voltage will most likely damage the LED. = ((IF / 1000) * R) + FV You get descending brightness with 3.3V circuits. All colors are safe to use with 5V circuits. The LED voltage must be at least FV to get some light. If you use multiple colors in the same circuit, you can add an extra resistor to some to balance the brightness. For example, if you add an external 150-220 ohm resistor to a red LED, you can reduce the brightness to balance with blue or green LEDs. If you have a microcontroller you can also use a technique called PWM to adjust the apparent brightness of each LED. My only issue with them, which I didn't deduct a rating for, is that each LED has the same built-in 150 ohm resistor. Taking AC forward current and forward voltage into account, the values had to be changed to optimize for 3.3V circuits (based on the operating voltage of the Lilypad or Flora boards) or at least to work directly with 5V circuits with the maximum voltage of 5 V is as follows: red, yellow from 130 to 150 ohms, blue, green from 60 to 90 ohms, white from 30 to 57 ohms. At 3.3V, only the red and yellow LEDs require a very small 45 to 65 ohm resistor. Again, if you need to balance the brightness, you can add an external resistor. Perhaps this information and/or formula will help you determine the best value.