manshuk89 said:i am currently using an atmega8 to control my lcd.
i am using ic7805 voltage regulator to provide for its vcc.
i have shorted avcc to vcc. should i do the same for avcc as well... or does it need some other external reference?
http://www.atmel.com/dyn/resources/prod_documents/doc2486.pdfAtmega8 Datasheet said:The ADC converts an analog input voltage to a 10-bit digital value through successive approximation. The minimum value represents GND and the maximum value represents the voltage on the AREF pin minus 1 LSB. Optionally, AVCC or an internal 2.56V reference voltage may be connected to the AREF pin by writing to the REFSn bits in the ADMUX Register. The internal voltage reference may thus be decoupled by an external capacitor at the AREF pin to improve noise immunity.
Xitami said:in ATmea8 avcc and vcc are shorted internaly, mega88 works better
7805 as reference?
Xitami said:
The avref and avcc pins in the atmega8 microcontroller are used to provide the reference voltage for the analog-to-digital converter (ADC). These pins are connected to the internal voltage reference circuitry and are essential for accurate conversion of analog signals to digital values.
The avref and avcc pins should be connected to a stable voltage source, typically VCC or an external voltage reference, depending on the application. It is important to ensure that the voltage source used is clean and free from noise, as this can affect the accuracy of the ADC conversion.
No, it is not recommended to leave the avref and avcc pins unconnected. The ADC requires a stable reference voltage to accurately convert analog signals, and leaving these pins unconnected can result in inaccurate readings.
Yes, it is possible to use an external voltage reference for the ADC in atmega8. This can be done by connecting the avref pin to the external reference voltage, instead of the internal reference. However, it is important to ensure that the external reference voltage meets the requirements of the ADC.
Connecting avref or avcc to a different voltage source can damage the atmega8 microcontroller and affect the accuracy of the ADC. It is important to double check the connections and ensure that the correct voltage source is used to prevent any damage.