Using the Arduino Nano's PWM output and a lowpass filter to obtain the desired DC signal to use as a voltage reference

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Other Materials from the Main Document

• Article «Adaptive resolution for ADCs»
• Figure 1. Sample inductor voltage versus time curve for a circuit measuring the voltage across an inductor when a DC step voltage is applied through a series resistor. Note the flat slope after 3 seconds, which will increase the relative error of the measurement
• Figure 2. Change in adaptive resolution using the Microchip ATmega328P's internal ADC with either reference V_CC voltage of 5 V or internal reference of 1.1 V
• Figure 3. This code continuously reads the ADC connected to analog pin A0. If A0 voltage < 1.1 V, the ADC reference is switched to 1.1 V. If A0 > 1.1 V, the ADC reference is switched to V_CC
• Figure 4. Using an external DAC (MAX5362) controlled by the Arduino Nano to provide more reference levels
• Figure 5. Using the Arduino Nano's PWM output and a lowpass filter to obtain the desired DC signal to use as a voltage reference
• Figure 6. Using a resistor ladder and an analog switch, e.g., TI TMUX1204, to select different nodes on the ladder to generate tailored voltage reference values