| Summary: | Aiming at the demand for intelligent detection and control of alcoholic gas concentration in the fields of the national economy, people′s productions and lives and so on, a wireless intelligent alcohol concentration detector is designed and developed in this paper. The instrument adopts the STC90C52RC microcomputer to control the 10-bit A/D converter TLC1549 to acquire the output voltage signal of the alcohol concentration sensor TGS2620. The alcohol concentration value is obtained by data processing. This value is displayed in real time by the LCD module DM-162, broadcasted by the speech recording and playback circuit ISD2560, and sent to the upper computer by the wireless transceiver chip nRF24L01 respectively. The user interface of the upper computer is developed by employing the general object-based programming language Microsoft Visual Basic 6.0 to display and save the alcohol concentration data. In the software, the anti-pulse interference average filtering algorithm is used to suppress the pulsating interference in the sampled data. The piecewise linear interpolation method is used for scaling transformation so as to improve the real-time performance of the system. And the linear fitting technique based on least square method is used to correct the system error. The actual testing results show that the measurement accuracy of the instrument is less than ±2% and the communication distance is less than 100 m, which verifies the correctness and effectiveness of the design.
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