Title:
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A novel sensor-bridge-to-microcontroller interface
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Author:
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Custodio Ruiz, Ángel; Bragós Bardia, Ramon; Pallàs Areny, Ramon
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Other authors:
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica; Universitat Politècnica de Catalunya. GRUP ISI - Grup d'Instrumentació, Sensors i Interfícies |
Abstract:
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Sensor bridges are usually interfaced to microcontrollers by supplying the bridge with a voltage or current and digitizing the resulting voltage or current after being amplified and low-pass filtered. This paper proposes an alternative method to interface a sensor bridge to a microcontroller that does not need any active component between the bridge and the microcontroller The bridge is considered a network with three inputs and one output. The resistance of each input to the output depends on the measurand. Using each input in turn to charge a capacitor connected to the bridge output yields three different time intervals. For a full bridge (a sensor at each arm), the ratio between the difference between two time intervals and the third time interval yields the fractional resistance change. Two-point calibration reduces zero and gain errors attributable to the electrical parameters of the ports of the microcontroller. The absolute error for a 15 psi (103.4 kPa) pressure sensor with 5000 Ω arms and a full-scale output of 125 mV is below 0.05% of full scale, which is better than 1 LSB for an 11 bit ADC |
Abstract:
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Peer Reviewed |
Subject(s):
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-Àrees temàtiques de la UPC::Enginyeria electrònica::Instrumentació i mesura::Sensors i actuadors -Àrees temàtiques de la UPC::Enginyeria electrònica::Microelectrònica -Detectors -Electronic controllers -Microelectronics -Sensor bridge -Microcontroller interfaces -Sensors -Microcontroladors |
Rights:
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Document type:
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Conference Object |
Published by:
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Institute of Electrical and Electronics Engineers
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