Using the ATAVRAUTO200
2-4 ATAVRAUTO200 User Guide
7698A–AUTO–01/07
2.2 Power Supply
The on-board power supply circuitry is supplied through the LIN connector.
2.2.1 LIN powered The LIN connector power line is used to provide VBAT to the ATAVR AUTO200 LIN
transceiver.
A LIN ne twork has to be connected to have yo ur LIN interf ace function (Input supply
from 8 up to 18V DC, see Figure 2-3 on page 5) .
2.3 Oscillator Sources
The ATAVRAUTO200 board allows only one oscillator source:
Internal RC oscillator (Default configuration).
Note: The “Divide by 8” Fuse is configured by default. The first step in the demonstra-
tion application is to clear the prescaler to have the internal RC oscillator run-
ning at 8MHz:
CLKPR = (1<<CLKPCE); //! Clear Prescaler
CLKPR = 0;
2.3.1 Interal RC oscillatorn
A LIN Slave node with a run-tim e oscillator calibration can be used with the internal RC
oscillator.
At ambiant temperature and normal Vcc, the i nternal oscillator is precise enough to be
complia nt with LIN 1.3 and 2.0 specific ations. F or wider tempera ture and/ or power
ranges, a run-time calibration of the inter nal RC oscillator can be used as explained in
the application note AVR140: “ATMega48/88/168 family run-time calibration of the inter-
nal RC oscillator” available on the Atmel website.
2.4 On-board Resources
2.4.1 LIN & Power supply
The LIN screwed connector allows the user to select his own connector.
Note: The LIN power supply input is reverse voltage protected.
LIN transceiver control is realized by the micrcontroller. All modes de pend on microcon-
troller’s ports configuration.