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Internet of Things-Compliant Platforms for Inter-Networking Metamaterials
Published in Christos Liaskos, The Internet of Materials, 2020
UART stands for Universal Asynchronous Receiver-Transmitter and is one of the simplest and oldest forms of device-to-device digital communication. UART is not a communication protocol like SPI and I2C, but a physical circuit in a micro-controller or a stand-alone IC. UARTs transmit data asynchronously, which means there is no clock signal to synchronize the output of bits from the transmitting UART to the sampling of bits by the receiving UART. Instead of a clock signal, the transmitting UART adds start and stop bits to the data packet being transferred. These bits define the beginning and end of the data packet so the receiving UART knows when to start reading the bits. There are many different speeds supported on UARTs from 300 baud to 115200 baud. UART uses 2 wires and thus it supports full duplex communication as shown in Fig. 6.8.
Semiconductor memory, input and output, and peripheral circuits
Published in D.A. Bradley, N.C. Burd, D. Dawson, A.J. Loader, Mechatronics, 2018
D.A. Bradley, N.C. Burd, D. Dawson, A.J. Loader
The rate at which data is transmitted and received is called the baud rate. The UART transmits and receives one bit of data per baud clock, and the baud rate is therefore specified as the number of bits per second. During the reception of data, account must be taken of the fact that the clock in the transmitting UART is asynchronous to that in the receiving UART. To overcome this problem the incoming byte contains a start bit which is used to synchronize the receiver clock with the incoming data. The data line is then sampled in the middle of a bit transmission using a signal derived from the baud clock, as in Fig. 12.8a. A common way of implementing this condition is for the receiver to use a clock frequency which is a multiple of the baud rate, and to provide an internal divider to create a narrow pulse signal, shown in Fig. 12.8b, which is used by the UART to sample the data line. A typical multiply/divide number is 16.
Interfacing Digital Logic to the Real World: Sensors, Analog to Digital, and Digital to Analog
Published in A. Arockia Bazil Raj, FPGA-Based Embedded System Developer's Guide, 2018
The UART is basically a data transmission/reception protocol through which data can be transferred bitwise without any reference clock input. The UART is also called a serial COM port or RS232 standard COM port. While transferring the data, the serial port sends a logical 1 as a negative voltage and a logical 0 as a positive voltage. When no data are being transferred, the serial port transmits logic 1 (i.e., negative voltage) and the port is said to be in a “mark or stop” state. The serial port can also be forced to be in “space or start” state by transferring logic 0 (i.e., positive voltage). The output signal level usually swings between +12 V and −12 V at the output of the COM port, as shown in Figure 7.14a. Logic 0 is defined between +5 V and +12 V, and logic 1 is defined between −5 V and −12 V, with ±3 V for the noise margin. The signal voltage between +3 V and −3 V is also called a “dead area” designed to absorb the line noise. When transmitting a byte, the UART first sends a “start” bit, which is a logic 0 followed by 8 data bits, followed by two “stop” bits, which is a logic 1, as shown in Figure 7.14b. This order of sending the bits has to repeated for each byte that needs to be sent.
IoT based multi-purpose smart fabric curtain
Published in Australian Journal of Electrical and Electronics Engineering, 2022
R. Sriharini, N Edna Elizabeth, D. Supriya, V. S Surenther, S. Sneha
Using the mobile application, the curtain can be calibrated (which has to be done before opening/closing the curtain), opened and closed. A step motor that is controlled by the microcontroller may be used for this operation. ULN2003A driver is used to set the motor off. Based on the users’ selection, commands or data are sent to a border router through the mobile application via Internet, using IPv4 or IPv6. Using the IEEE 802.15.4 protocol, the data is then transmitted to the radio controller. The data, is later sent from there to the microcontroller via UART (Universal Asynchronous Receiver Transmitter). UART is a serial data transmission protocol used in microcontrollers.
Enhanced performance of the mechanical respiratory system by FPGA-digital based on PID Controller
Published in Cogent Engineering, 2023
Dang Quy Phan, Ha Quang Thinh Ngo
UART, Universal asynchronous receiver transmitter, is a computer hardware device for asynchronous serial communication in which the data format and transmission speeds are configurable. It sends data bits one by one, from the least significant to the most significant, framed by start and stop bits so that precise timing is handled by the communication channel. The electric signalling levels are handled by a driver circuit external to the UART. Two common signal levels are RS-232, a 12-volt system, and RS-485, a 5-volt system. Early teletypewriters used current loops.
IoT-based patient stretcher movement simulation in smart hospital using type-2 fuzzy sets systems
Published in Production Planning & Control, 2023
C. B. Sivaparthipan, M. Anand, Nidhi Agarwal, Mallika Dhingra, Laxmi Raja, Akila Victor, S. A. Amala Nirmal Doss
With the help of the interface design, the patient stretcher can be tracked with the help of the GPS tracking sensor. This sensor connects to the sensor attached to the stretcher. Then it forms the system to produce the information about where the bed is located and the patient details who occupied it. Here the medical images are captured, and the many types of the sensor make a full analysis of the system to produce the formation of the digital information in the communication capabilities (Kataria et al. 2021). The Digital Imaging and Communications in Medicine (DICOM) standard provides a thorough description of the information content, structure, encoding, and communications protocols for the electronic transaction of diagnostic and therapeutic images as well as image-related data. It is most frequently used to store and transmit medical images, making it possible to integrate medical imaging equipment from many manufacturers, including scanners, servers, workstations, printers, network infrastructure, and picture archiving and communication systems (PACS). This mechanism provides automatic movements of the stretcher. Between the stretcher and microcontroller, the driver circuit act as an interface. AT mega microcontroller is the heart of the system and has 54 input and output pins. It has 4 Universal asynchronous receiver-transmitter (UARTs) and 16 analogue inputs. A UART is typically an individual integrated circuit (IC) used for serial communications through a serial port on a computer or peripheral device. Microcontroller chips frequently include one or more UART peripherals. Automobiles, smart cards, and SIMs all make use of specialised UARTs. In UART, local clock references are used to detect data through baud rate generation. The sender generates a clock signal that determines the transmission rate, which the receiver also uses to detect incoming data. The receiver generates its clock signal and uses it to sample the data at regular intervals determined by the local clock. Data is transmitted as a series of bits, starting with a start bit, followed by data bits, and ending with a stop bit. The receiver samples the data at the midpoint of each data bit using the local clock reference to ensure accurate detection, even when the sender and receiver clocks are not perfectly synchronised. The sensors provide the data to the controller through the input pins and update the data to the server using the UART port. It makes the stretcher move. Here, the biometric sensor gets each patient’s information through the fingerprint. The respiration sensor is used for monitoring and gives information about the depth of breathing. The respiration sensor is a sensitive girth sensor that is attached to a length-adjustable webbing belt by an easy-fitting high durability woven elastic band. The respiration waveform is produced once the chest or abdominal expansion or contraction is recognised. The heartbeat sensor is also attached to this system. When the patient’s fingerprint is placed on the sensor, the digital output of the patient’s heartbeat is shown in the indicator.