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Which register is used to setup the ADC clock?
The basic configuration task will be to enable the desired signal paths. In this example to the ADC. The function of the input output pins is configured using two control registers CRL (Control Register Low – shown below) and CRH (Control Register High).
What is an ADC channel?
The ADC converts an analog input voltage to a 10-bit digital value. The analog input channel is selected by writing to the MUX bits in ADMUX. This allows the selection of any of the 8 channels, AGND, or a fixed voltage reference. The ADC has two different operating modes.
How is the ADC resolution determined by the digital number?
The number of binary digits (bits) that represents the digital number determines the ADC resolution. However, the digital number is only an approximation of the true value of the analog voltage at a particular instant because the voltage can only be represented (digitally) in discrete steps.
Why is acquisition time constant in ADC output?
This is because the MSB (most significant bit) is computed first and then the next bit etc., until the final bit is computed and this necessitates that the analogue signal is “held” constant throughout the process. This is usually done with a sample and hold circuit.
When does the ADC start in single conversion mode?
In Single Conversion mode, the ADC does one conversion. This mode is started either by setting the ADON bit in the ADC_CR2 register (for a regular channel only) or by an external trigger (for a regular or injected channel), while the CONT bit is 0. Once the conversion of the selected channel is complete: If a regular channel was converted:
How is the Adc connected to the multiplexer?
The ADC converts an analog input voltage to a 10-bit digital value. The ADC is connected to an 8-channel Analog Multiplexer which allows each pin of PortA to be used as input for the ADC. The analog input channel is selected by writing to the MUXbits in ADMUX.