Light Emitting Diodes
Typical Voltage Drops
| Color | Voltage Drop |
|---|---|
| Red | 1.7 |
| Bright Red | 1.9 |
| Orange | 2.0 |
| Green | 2.1 |
| Bright White | 3.4 |
| Blue | 3.4 |
Using LEDs
By syncing the LED to the GPIO, you can remove the constraint of the GPIO max current.
Multi-Color LEDs
Calculating Resistance Needed
For brightest LED without exceeding max GPIO current of 12 mA (ESP8266):
V = I * R
R = V / I = 3.3/0.012 = 275 ohms
Question:
Should we consider the voltage drop in the following calculation? Should it be:
V = I * R
R = ( Vss - Vdrop ) / I = (3.3 - 1.7) / 0.012 = 133 ohms