Design of Touch Screen Driver Based on Linux

2011 ◽  
Vol 467-469 ◽  
pp. 818-822
Author(s):  
Dong Yu Zhang
Keyword(s):  
Data Acquisition ◽  
Control Method ◽  
Hardware Design ◽  
Touch Screen ◽  
Data Conversion ◽  
Practice Level ◽  
State Detection ◽  
Touch Point ◽  
Coordinate Conversion ◽  
Spi Interface

This paper introduces the touch screen driver design based on Linux plays an important role in applications of touch screen. In order to further explore embedded touch screen driver design, and then optimize and improve existing drivers at practice level, this paper accomplished the design of touch screen driver using SPI interface and ADS7843 touch screen chip controller based on Samsung S3C2410s microprocessor. We designed the touch screen hardware interrupt program using the bottom half mechanism of the kernel timer, utilized 16 clock cycles of coordinate conversion sequences to achieve touch point based data acquisition and present the process of coordinate collection. The touch screen driver ran well on the UP-NETARM2410-S platform. The hardware design was verified to be simple and reliable while the corresponding software accomplished touch state detection and touch data conversion efficiently. The touch screen control method is simple, efficient and easy to realize.

scholarly journals Towards Continuous and Ambulatory Blood Pressure Monitoring: Methods for Efficient Data Acquisition for Pulse Transit Time Estimation

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7106
Author(s):  
Oludotun Ode ◽  
Lara Orlandic ◽  
Omer T. Inan
Keyword(s):  
Blood Pressure ◽  
Embedded System ◽  
Data Acquisition ◽  
Transit Time ◽  
Ambulatory Blood Pressure ◽  
Field Experiments ◽  
Control Method ◽  
Pulse Transit Time ◽  
Huffman Coding ◽  
Physiological Data

We developed a prototype for measuring physiological data for pulse transit time (PTT) estimation that will be used for ambulatory blood pressure (BP) monitoring. The device is comprised of an embedded system with multimodal sensors that streams high-throughput data to a custom Android application. The primary focus of this paper is on the hardware–software codesign that we developed to address the challenges associated with reliably recording data over Bluetooth on a resource-constrained platform. In particular, we developed a lossless compression algorithm that is based on optimally selective Huffman coding and Huffman prefixed coding, which yields virtually identical compression ratios to the standard algorithm, but with a 67–99% reduction in the size of the compression tables. In addition, we developed a hybrid software–hardware flow control method to eliminate microcontroller (MCU) interrupt-latency related data loss when multi-byte packets are sent from the phone to the embedded system via a Bluetooth module at baud rates exceeding 115,200 bit/s. The empirical error rate obtained with the proposed method with the baud rate set to 460,800 bit/s was identically equal to 0%. Our robust and computationally efficient physiological data acquisition system will enable field experiments that will drive the development of novel algorithms for PTT-based continuous BP monitoring.

A LCD Touch Screen Controller Based on LPC2138

2011 ◽  
Vol 383-390 ◽  
pp. 6914-6919 ◽  
Author(s):  
Jing Gao ◽  
Lian Qing Zhu ◽  
Yang Kuan Guo ◽  
Hao Meng
Keyword(s):  
Control Method ◽  
Detection System ◽  
Liquid Crystal Display ◽  
Touch Screen ◽  
High Accuracy ◽  
Erythrocyte Sedimentation ◽  
Synchronization Algorithm ◽  
Great Reliability ◽  
Working Principle ◽  
And Control

The user interface made of a LCD (liquid crystal display) screen and a touch screen based on LPC2138 is presented in this paper. The hardware design of the LCD and the touch screen is introduced and the software flow of the LCD and the touch screen is also described in this paper. And this paper proposes the synchronization algorithm which can achieve the LCD and the touch screen point by point with high accuracy and great reliability. On the basis of analyzing the principle of the embedded touch panel system, the working principle and control method of the dedicated controller DV320240GB touch screen are analyzed. The method for obtaining the coordinates of the touch screen and the synchronization algorithm of the LCD display are proposed to improve the efficiency of the touch screen and the LCD. The above-mentioned design has been successfully applied in ESR (erythrocyte sedimentation rate) detection system.

scholarly journals 401 MHz transistorised radiosonde transmitter

MAUSAM ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 87-90
Author(s):  
S. K. SRIVASTAVA ◽  
S. K. BINDRA ◽  
M. P. BHARDWAJ
Keyword(s):  
Data Acquisition ◽  
Optimum Design ◽  
Frequency Band ◽  
Power Output ◽  
Data Conversion ◽  
Accurate Data

This paper describes a transistorised radiosonde transmitter which was designed to replace valve version earlier used in national upper air l1etwork for upper air data acquisition. The transmitter operates in 400.6-406 MHz frequency band (tunable) with 500 mill watt power output utilising a 22.5V water activated battery, Stripling technique has been deployed to obtain the optimum. design and transmitted meets all the stringent requirements laid down for accurate data conversion and transmission. The system IS In routine use In the national upper air network and the performance is satisfactory.  

Research on Multi-Point Calibration and Touch Pressure of Touch-Screen

2012 ◽  
Vol 198-199 ◽  
pp. 1290-1293 ◽  
Author(s):  
Xiu Hong Jiang ◽  
Fu Hai Duan ◽  
Rui Guo
Keyword(s):  
Touch Screen ◽  
Test Results ◽  
Pressure Threshold ◽  
Calibration Algorithm ◽  
Point Set ◽  
Two Measures ◽  
Target Environment ◽  
Low Sensitivity ◽  
Coordinate Conversion ◽  
Calibration Coefficients

In view of the inaccuracy and low sensitivity of resistive touch-screen in small point target environment, two measures were proposed. First, based on the existing three-point calibration algorithm, more points were sampled to improve coordinate conversion precision, greedy algorithmm reduced the random calibration point set, and least squares algorithm fit the final calibration coefficients. Another measure was to utilize the touch pressure measurement and pressure threshold decision to remove invalid click. Finally, test results show that multi-point calibration with greedy algorithm can improve the precision of coordinate calibration, and the adoption of pressure decision can effectively enhance the system’s adaptability to touch intensity.

Navigation Between Menu Screens and Multiple Touch Points on a Touch Screen Tablet to Access and Complete Multi-Step Tasks Using Video Prompting

Inclusion ◽  
2013 ◽  
Vol 1 (2) ◽  
pp. 121-132 ◽  
Author(s):  
Linda C. Mechling ◽  
Ashley M. Foster ◽  
Kevin M. Ayres
Keyword(s):  
Young Adults ◽  
Intellectual Disability ◽  
Touch Screen ◽  
Video Prompting ◽  
Skill Performance ◽  
Touch Point ◽  
Multiple Probe

Abstract The purpose of this study was to evaluate the capacity of three young adults with intellectual disability to independently operate a touch screen tablet, including examining their ability to navigate between three different menu screens, each with four different touch point options (branching and to access and complete multi-step tasks using video prompting. A multiple probe across subjects design was used and data were collected on these young adults' abilities to navigate between screens and perform steps for becoming more independent in cooking, cleaning, and folding tasks. All three participants learned to navigate between different menu screens, access different video programs, complete the multi-step tasks, and maintained skill performance from 10 to 61 days.

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