=== Formula ===
* calculation of resistance RD R_LED_R <math>\frac{U_r}{I} = \frac{VDD - U_{LR}}{I} = \frac{3.3V - 1.8V}{10mA}</math> = ''' 150 ohm '''* calculation of resistance RD R_LED_O <math>\frac{U_r}{I} = \frac{VDD - U_{LR}}{I} = \frac{3.3V - 1.9V}{10mA}</math> = ''' 140 ohm '''
= Layout =