Resistors and LEDs
The characteristic of LEDs can vary quite a bit. The voltage drop usually depends on the color, but your LED might be different. This is just a guide, check your datasheet or meassure it. Typically red, orange, yellow LEDs have a voltage drop of 1.8V-2.0V and green, blue, pink/purple, white of 3.2V-3.3V.
 Direct |
 Charlieplexed |
Direct
| red orange yellow | green blue pink/purple white | ||||||||
| V/mA | 5mA | 10mA | 15mA | 20mA | V/mA | 5mA | 10mA | 15mA | 20mA |
|---|---|---|---|---|---|---|---|---|---|
| 3.0V | 220Ω | 100Ω | 82Ω | 68Ω | 3.0V | - | - | - | - |
| 3.3V | 330Ω | 150Ω | 100Ω | 68Ω | 3.3V | - | - | - | - |
| 3.7V | 390Ω | 180Ω | 120Ω | 100Ω | 3.7V | 100Ω | 47Ω | 33Ω | 33Ω |
| 5.0V | 680Ω | 330Ω | 220Ω | 150Ω | 5.0V | 390Ω | 220Ω | 120Ω | 100Ω |
Charlieplexed
| red orange yellow | green blue pink/purple white | ||||||||
| V/mA | 5mA | 10mA | 15mA | 20mA | V/mA | 5mA | 10mA | 15mA | 20mA |
|---|---|---|---|---|---|---|---|---|---|
| 3.0V | 100Ω | 47Ω | 39Ω | 33Ω | 3.0V | - | - | - | - |
| 3.3V | 150Ω | 68Ω | 47Ω | 39Ω | 3.3V | - | - | - | - |
| 3.7V | 180Ω | 100Ω | 68Ω | 47Ω | 3.7V | 47Ω | 33Ω | 22Ω | 15Ω |
| 5.0V | 330v | 150Ω | 100Ω | 82Ω | 5.0V | 180Ω | 100Ω | 68Ω | 47Ω |