Implementasi Analog Front End pada Sensor Kapasitif untuk Pengaturan Kelembaban Menggunakan Mikrokontroller STM32

Sensor kapasitif merupakan jenis sensor yang mengubah stimulus fisik menjadi Perubahan kapasitansi. Pada sensor kapasitif, adanya stray capacitance atau kapasitansi parasitik pada sensor dapat menyebabkan kesalahan dalam pengukuran. Dalam aplikasi pengaturan kelembaban, dibutuhkan sistem pengukuran kelembaban dengan kesalahan minimum untuk mendapatkan nilai setting point dengan galat minimum. Maka diperlukan implementasi analog front end yang dapat meminimalisir kesalahan akibat stray capacitance pada sensor kapasitif untuk pengukuran kelembaban relatif. Pada sistem pengukuran sensor kapasitif ini, sensor dieksitasi dengan sinyal AC yang dihasilkan oleh generator sinyal pada frekuensi 10 KHz, kemudian diimplementasikan analog front end untuk mengondisikan sinyal dari sensor. Keluaran dari analog front end dikonversi menjadi sinyal DC menggunakan demodulator sinkron dan filter low pass lalu dikonversi menjadi data digital menggunakan ADC di mikrokontroller STM32. Hasil pengukuran yang didapatkan dengan implementasi analog front end kemudian kemudian gunakan untuk mengatur kelembaban pada sebuah plant growth chamber. Berdasarkan hasil dari pengujian, rangkaian analog front end dapat mengompensasi stray capacitance dengan kesalahan pembacaan nilai kapasitansi maksimal sebesar 4.2% pada kondisi stray capacitance sebesar 236,6pF, 174,3pF dan 115,7pF. Implementasi analog front end pada pengaturan kelembaban menghasilkan galat pada setting point maksimal sebesar 8.8% untuk nilai RH 75% dan 33%

PVDF phased-array analog front end

Need a board to test algorithms for CDMA signal transmission and processing? You can employ an array of broadband receivers using thin polyvinylidene fluoride (PVDF) sheets as the transducers. Here you learn about the analog electronics required to condition the analog signals for digitization and the subsequent transmission line implementation

A GPP-Based Software-Defined Radio Front-End for WLAN Standards

This paper presents a software-defined radio testbed for the physical layer of wireless LAN standards. All baseband physical layer functions have been successfully mapped on a Pentium 4 processor that performs these functions in real-time. This has been tested in combination with a CMOS integrated wideband analog front-end containing a low noise amplifier, downconversion mixers and filters. The testbed consists of both a transmitter and a receiver. The transmitter contains a transmitter PC with a DAC board, an Agilent E4438C generator for upconversion and an antenna. The receiver consists of an antenna, a wideband SDR analog frontend and a receiver PC with an ADC board. On this testbed we have implemented two different types of standards, a continuous-phase-modulation based standard, Bluetooth and an OFDM based standard, HiperLAN/2. However, our testbed can easily be extended to other standards, because the only limitations in our testbed are the maximal channel bandwidth of 20 MHz, the dynamic range of the wideband SDR analog front-end and of course the processing capabilities of the used PC

Baseband analog front-end and digital back-end for reconfigurable multi-standard terminals

Multimedia applications are driving wireless network operators to add high-speed data services such as Edge (E-GPRS), WCDMA (UMTS) and WLAN (IEEE 802.11a,b,g) to the existing GSM network. This creates the need for multi-mode cellular handsets that support a wide range of communication standards, each with a different RF frequency, signal bandwidth, modulation scheme etc. This in turn generates several design challenges for the analog and digital building blocks of the physical layer. In addition to the above-mentioned protocols, mobile devices often include Bluetooth, GPS, FM-radio and TV services that can work concurrently with data and voice communication. Multi-mode, multi-band, and multi-standard mobile terminals must satisfy all these different requirements. Sharing and/or switching transceiver building blocks in these handsets is mandatory in order to extend battery life and/or reduce cost. Only adaptive circuits that are able to reconfigure themselves within the handover time can meet the design requirements of a single receiver or transmitter covering all the different standards while ensuring seamless inter-interoperability. This paper presents analog and digital base-band circuits that are able to support GSM (with Edge), WCDMA (UMTS), WLAN and Bluetooth using reconfigurable building blocks. The blocks can trade off power consumption for performance on the fly, depending on the standard to be supported and the required QoS (Quality of Service) leve

CMRR Boosted Instrumentation Amplifier for Biomedical Application

This research paper discusses about a design of an amplifier for its use in an Analog Front End for Biomedical signal acquisition. The design of an AFE is also specific to the signal of interest. This paper deals with the design of an Analog Front End using 180nm process. An amplifier is a key component of an AFE. For instrumentation amplifier to satisfy theoretical results the OPAMP used must be close to ideal. The simulations are performed using TANNER EDA tool

Implementasi Analog Front End Pada Sensor Kapasitif Untuk Pengaturan Kelembaban Menggunakan Mikrokontroller STM32

Sensor kapasitif merupakan jenis sensor yang mengubah stimulus fisik menjadi perubahan kapasitansi. Pada sensor kapasitif, adanya stray capacitance atau kapasitansi parasitik pada sensor dapat menyebabkan kesalahan dalam pengukuran. Dalam aplikasi pengaturan kelembaban, dibutuhkan sistem pengukuran kelembaban dengan kesalahan minimum untuk mendapatkan nilai setting point dengan galat minimum. Maka diperlukan implementasi analog front end yang dapat meminimalisir kesalahan akibat stray capacitance pada sensor kapasitif untuk pengukuran kelembaban relatif. Penelitian pada tugas akhir ini adalah menentukan pengaruh dari implementasi analog front end pada pengukuran kelembaban relatif dengan sensor kapasitif untuk aplikasi pengaturan kelembaban menggunakan mikrokontroller STM32. Analog front end merupakan rangkaian elektronika yang berfungsi untuk mengondisikan sinyal dari sensor sebelum menuju akuisisi data. Pada tugas akhir ini digunakan sensor kelembaban berbasis kapasitif HS1101. Keluaran dari analog front end dikonversi menjadi sinyal DC dengan demodulator sinkron dan filter low pass kemudian didigitalkan menggunakan ADC mikrokontroller STM32. Pengukuran kelembaban relatif dengan implementasi analog front end kemudian digunakan untuk pengaturan kelembaban yang menggunakan aktuator berupa humidifier ultrasonik dan kipas ventilasi. Berdasarkan hasil dari pengujian, rangkaian analog front end dapat mengompensasi stray capacitance dengan kesalahan pembacaan nilai kapasitansi maksimal sebesar 4.2% pada kondisi stray capacitance sebesar 236,6pF, 174,3pF dan 115,7pF. Implementasi analog front end pada pengaturan kelembaban menghasilkan galat pada setting point maksimal sebesar 8.8% untuk nilai RH 75% dan 33%

Frequency to Voltage Converter Analog Front-End Prototype

The frequency to voltage converter analog front end evaluation prototype (F2V AFE) is an evaluation board designed for comparison of different methods of accurately extracting the frequency of a sinusoidal input signal. A configurable input stage is routed to one or several of five separate, configurable filtering circuits, and then to a configurable output stage. Amplifier selection and gain, filter corner frequencies, and comparator hysteresis and voltage reference are all easily configurable through the use of jumpers and potentiometers