title: Smart Capture Modules for Direct Sensor-to-FPGA Interfaces.
abstract: Direct sensor-digital device interfaces measure time dependent variables of simple circuits to implement analog-to-digital conversion. Field Programmable Gate Arrays (FPGAs) are devices whose hardware can be reconfigured to work in parallel. They usually do not have analog-to-digital converters, but have many general purpose I/O pins. Therefore, direct sensor-FPGA connection is a good choice in complex systems with many sensors because several capture modules can be implemented to perform parallel analog data acquisition. The possibility to work in parallel and with high frequency clock signals improves the bandwidth compared to sequential devices such as conventional microcontrollers. The price to pay is usually the resolution of measurements. This paper proposes capture modules implemented in an FPGA which are able to perform smart acquisition that filter noise and achieve high precision. A calibration technique is also proposed to improve accuracy. Resolutions of 12 effective number of bits are obtained for the reading of resistors in the range of an example piezoresistive tactile sensor.
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. oballe@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. oballe@uma.es.
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Oballe-Peinado
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. fvidal@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. fvidal@uma.es.
authors.forename: Fernando
authors.initials: F
authors.lastname: Vidal-Verdú
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. jsd@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. jsd@uma.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Sánchez-Durán
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. julian@elca.uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. julian@elca.uma.es.
authors.forename: Julián
authors.initials: J
authors.lastname: Castellanos-Ramos
authors.affiliation: Departamento de Electrónica, Universidad de Málaga, Andalucía Tech, Campus de Teatinos, Málaga 29071, Spain. jahidalgo@uma.es.|Instituto de Investigación Biomédica de Málaga (IBIMA), Málaga 29010, Spain. jahidalgo@uma.es.
authors.forename: José A
authors.initials: JA
authors.lastname: Hidalgo-López
mesh_terms: D003201:Computers; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D008962:Models, Theoretical
keywords: FPGAs; direct sensor-to-digital device interface; parallel analog data acquisition