10-04-2017, 08:11 PM
pic microcontroller based wireless temperature and heart beat read out mudit agarwal microcontroller based wireless temp
Microcontroller Based Wireless Temperature And HeartBeat Read Out suitable for operation in a small office/home environment. This system is easy to operate, with Visual LCD. Many individuals and organizations may, for various reasons, wish to use electronic surveillance techniques at some time or another. The idea is to use off-the-shelf RF Tx/Rx modules. The weather keeps us continually occupied. Some people have even made it their profession. At home too, we like to measure all kinds of things related to our climate. That is why weather stations are available in all types and sizes. If we want to know the temperature inside and outside then purpose-built indoor/outdoor thermometers are available. In the past the outside sensor of these weather stations was connected with a wire, it is now fairly standard to use RF transmission for this data. This Wireless transmitters units usually make use of the 315-MHz band. These modules, once a rare commodity, are now widely and cheaply available. In this particular discussion, we shall be using ASK (Amplitude Shift Keying) based TX/RX pair operating at 315 MHz. The transmitter module accepts serial data at a maximum of 2400bps. They are directly interfaced to a microcontroller. At the RX end, the receiver microcontroller receives the signal via the RF receiver module, decodes the serial data and reproduces the original data in the temperature and Heat Beat format.
Temperature Sensors
Temperature is one of the fundamental physical variables in most chemical and process control applications. Accurate and reliable measurement of the temperature is important in nearly all process control applications. Temperature sensors can be analog or digital. Some of the most commonly used analog temperature sensors are: thermocouples, resistance temperature detectors (RTDs) and thermistors. Digital sensors are in the form of integrated circuits. The choice of a sensor depends on the accuracy, the temperature range, speed of response, thermal coupling, the environment (chemical, electrical, or physical) and the cost. A popular voltage output analog integrated circuit temperature sensor is the LM35DZ, manufactured by National Semiconductor. This is a 3-pin analog output sensor which provides a linear output voltage of 10 mV/0C. The temperature range is 0
0C to +100 0C, with an accuracy of 1.5 0C.
Hear Beat Siganlling
The Heart Beat signal is obtained by LED and LDR combination. Pulses form hands interrupts the Light reaching the LDR and this signal is read by microcontroller, A logical zero is represented by a pulse in the first half of the bit time. A logical one is represented by a pulse in the second half of the bit time.
PIC Micro controller
Microcontrollers contain all the components required for a processor system in one chip, a CPU, memory and I/O. A complete system can therefore be built using one MCU chip and a few I/O devices such as a keypad, display and other inter facing circuits . Most of the pins are for input and output, and arranged as 5 ports: PORTA(5 pins),PORT B(8 pins), PORTC(8 pins), PORTD(8 pins) and PORTE(3 pins), giving a total of 32 I/O pins. These can all operate as simple digital I/O pins, but most have more than one function, and the mode of operation of each is selected by initializing various control registers within the chip. Port B is used for downloading the program to the chip flash ROM and RB0 and RB4 RB7 can generate an interrupt. Port C gives access to timers, while Port D can be used as a slave port, with Port E providing the control pins for this function.