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Analog to Digital Converters. Overview. What is an ADC? How does an ADC work? What are the important specifications of and ADC? The Wunderboard ADC Example program. What is an ADC?. Converts a voltage in a range into a number Most are 'single ended' (positive voltages only)
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Overview • What is an ADC? • How does an ADC work? • What are the important specifications of and ADC? • The Wunderboard ADC • Example program
What is an ADC? • Converts a voltage in a range into a number • Most are 'single ended' (positive voltages only) • Often in included in microcontrollers, not microprocessors
How does an ADC work? • Flash ADCs • Lots of circuitry using lots of power but very fast • Successive approximation • Slower but less power
What are the important specifications of and ADC? • Resolution(8 or 10bit) • Absolute Accuracy (± 2 LSB ) • Conversion Time (65 - 260 μs) • Number of Channels (Eight Multiplexed Single Ended Input Channels)
AVR Registers • ADMUX - ADC Multiplexer • ADCSRA - ADC Status Register A • ADCH and ADCL - ADC High and Low Result • ADCSRB - ADC Status Register B
Parting Thoughts • Most microcontrollers have ADCs built in • If choosing an ADC, check needed precision and speed