Atmel ATAVRAUTO200 Guide de l'utilisateur télécharger pdf (Page 7)

Using the ATAVRAUTO200

ATAVRAUTO200 User Guide 2-5

7698A–AUTO–01/07

Table 2-1. LIN ressources

Figure 2-3. LIN transceiver and power supply

Note: The LIN transceiver undervoltage protection can be disabled by removing the

NISP jumper.

Note: The NISP jumper has to be removed when programming.

2.4.2 Power supply measurement

The voltage measurement is realized with a bridge of resistors. The read value is 0.281

of the LIN power supply (47 KΩ / (47 KΩ + 120 KΩ)). Input voltage on channel 1 of the

ADC is limited to 5.1V by a zener diode. This will give a voltage reading range from 0 to

18.1V with Vcc as reference.

The power supply measurement can be performed using the A/D converter. See the

ATmega48/88/168 datasheet for how to use the ADC. The input voltage value (V

) is

calculated with the following expression:



Where: V

= Input voltage value (V)



ADC7

= Voltage value on ADC-1 input (V)

Function Port State Description

LIN_NSLP PD2 Low LIN transceiver in Sleep mode

High LIN transceiver in normal mode

NRES_LIN PC6 Low Perform MCU reset when NISP Jumper is inserted

High No Action

+VBat

3.55 V

ADC

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Atmel ATAVRAUTO200 Guide de l'utilisateur Page 7