Difference between revisions of "Extension Explorer 16"

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(→‎Formula)
(→‎Formula)
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* Resitor Pull-Up MAX :  
 
* Resitor Pull-Up MAX :  
 
<math>
 
<math>
−
R_{Pull-Up} = \frac{VDD - VDD_{low}}{I_L} = \frac{3.3 - 0.66}{2u}  
+
R_{Pull-Up_{max}} = \frac{VDD - VDD_{low}}{I_L} = \frac{3.3 - 0.66}{2u}  
 
</math>
 
</math>
 
= ''' 1.32 Mohms'''
 
= ''' 1.32 Mohms'''
 +
 +
''Remark'' : the resistor must be more less that the R_PULL-UP_max - usually, the value of 10kohm is using for the resistor pull-up.
 +
 +
* Current using when the switch is closed
 +
<math>
 +
I_{R_{Pull-Up}} = \frac{VDD - VDD_{low}}{R_{Pull-up}} = \frac{3.3 - 0.66}{10k}
 +
</math>
 +
= ''' 264 uA'''
  
 
= Layout =
 
= Layout =

Revision as of 02:02, 28 October 2014

Description

In French: Création d'une carte d'extension pour la carte Explorer (PROJET: Carte Explorer 16 & Exos sur les uC).

  • V1: un montage permettra de simuler un carrefour routier, composer de 4 feux (RGB)


in English: creation of one extansion board for the Explorer Board (see the links above)

  • V1: assembly will allow to simulate a crossroad (4 fires (RGB))

Digram - Schematic

Part Calculation of Electronics Digram

LED's for crossroad

  • the datasheet of the DSP implemented on the Explorer Board 16 (see pages 1 & 273) indicates that :
    • output current of I/O : I = 10mA
    • voltage I/O : VDD = 3.3V
  • the datasheet of the red LED (see pages 3) indicates that :
    • conduction voltage : ULR = VF = 1.8V
    • average current : I = 20mA
  • the datasheet of the orange LED (see pages 3 / 4 / 5) indicates that :
    • conduction voltage : ULO = VF = 1.9V
    • average current : I = 30mA
  • the datasheet of the green LED (see pages 3 / 4 / 5) indicates that :
    • conduction voltage : ULG = VF = 2.2V
    • average current : I = 30mA

Formula

  • calculation of resistance R_LED_R :

R_{LED_R}=\frac{U_r}{I}=\frac{V_{DD}-U_{LR}}{I}=\frac{3.3V-1.8V}{10mA} = 150 ohm

  • power dispersed by the resistance P_R_LED_R :

P_{R_{LED_R}}=\frac{R_{LED_R}^2}{I}=\frac{150^{2}}{10mA} = 15 mW

  • calculation of resistance R_LED_O :

R_{LED_O}=\frac{U_r}{I}=\frac{V_{DD}-U_{LO}}{I}=\frac{3.3V-1.9V}{10mA} = 140 ohm

  • power dispersed by the resistance P_R_LED_O :

P_{R_{LED_O}}=\frac{R_{LED_O}^2}{I}=\frac{140^{2}}{10mA} = 14 mW

  • calculation of resistance R_LED_G :

R_{LED_G}=\frac{U_r}{I}=\frac{V_{DD} - U_{LG}}{I}=\frac{3.3V-2.2V}{10mA} = 110 ohm

  • power dispersed by the resistance P_R_LED_G :

P_{R_{LED_G}}=\frac{R_{LED_G}^2}{I}=\frac{110^{2}}{10mA} = 11 mW

Switch for crossroad

  • the datasheet of the DSP implemented on the Explorer Board 16 (see pages 1, 278, 279) indicates that :
    • output current of I/O : I_output = 10mA
    • input current of I/O : I_output max = 5mA
    • voltage I/O : VDD = 3.3V
    • leakage current of I/O : 2uA
    • low state ('0') in voltage : 0,2 * VDD

Formula

  • voltage seens by the input of uC when it's a low state VDD_low :

VDD_{low} = VDD \cdot 0.2 = 3.3 \cdot 0.2 = 0.66 V

  • Resitor seens by the input of uC when it's a low state RIN_low :

RIN_{low} = \frac{VDD_{low}}{I_L} = \frac{0.66}{2u} = 330 kohms

  • Resitor Pull-Up MAX :

R_{Pull-Up_{max}} = \frac{VDD - VDD_{low}}{I_L} = \frac{3.3 - 0.66}{2u} = 1.32 Mohms

Remark : the resistor must be more less that the R_PULL-UP_max - usually, the value of 10kohm is using for the resistor pull-up.

  • Current using when the switch is closed

I_{R_{Pull-Up}} = \frac{VDD - VDD_{low}}{R_{Pull-up}} = \frac{3.3 - 0.66}{10k} = 264 uA

Layout

Components listing

Modification

Documentation

PDF FILE

required links

Contributor

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