Discussion Overview
The discussion revolves around the connections of AVcc and AVref in the ATmega8 microcontroller, particularly in relation to powering an LCD and using the Analog to Digital Converter (ADC). Participants explore whether AVcc should be connected to Vcc and the implications of such connections for functionality and noise immunity.
Discussion Character
- Technical explanation
- Debate/contested
Main Points Raised
- One participant mentions using an IC7805 voltage regulator to provide Vcc for the ATmega8 and questions whether AVcc should also be shorted to Vcc or require a different external reference.
- Another participant explains that AVcc is the power supply for the ADC and that AVref can be decoupled for noise immunity, suggesting that it does not necessarily need to be connected to anything unless a capacitor is used.
- Some participants assert that AVcc and Vcc are shorted internally, while others challenge this claim, stating that AVcc should be connected to a supply even if the ADC is not in use.
- There is a mention of the 7805 voltage regulator being used to supply Vcc, with questions about its suitability as a reference.
- Links to external resources are provided for further reference, but their relevance to the discussion remains unclear.
Areas of Agreement / Disagreement
Participants express differing views on whether AVcc and Vcc are internally shorted and whether AVcc needs to be connected to a supply. The discussion remains unresolved with multiple competing perspectives.
Contextual Notes
Some participants reference the ATmega8 datasheet, but there are conflicting interpretations regarding the internal connections and requirements for AVcc and AVref. The discussion highlights potential oversights in understanding the microcontroller's specifications.