This paper describes the design of a simple, low-cost microcontroller based heart rate measuring device with LCD output. Heart rate of the subject is measured from the finger using sensors and the rate is then averaged and displayed on a text based LCD.
The LCD of the heart beat monitor shows the beat per minute.The sensor part consists of sensing elements,LDR(light dependent resistor) and LED(light emitting diode),a comparator module,a low pass filter.Heart beat is sensed by the sensing elements and the comparator produces an amplified square wave output.The comparator output is given to a low pass filter and the filter output is fed to one of the digital inputs of PIC 16F877a type micro controller. The micro controller output ports drives the LCD.
This paper describes the design of a very low-cost device which measures the heart rate of the subject by clipping sensors on one of the fingers and then displaying the result on a text based LCD. Advantage of such a design is that it can be expanded and can easily be connected to a recording device or a PC to collect and analyse the data for over a period of time.
The short message system (SMS) of a standard mobile phone can be used for much more than just exchanging cryptic message. This application finds a humble mobile working for controlling external equipments. The SMS service provides by the service providers are comparatively low cost. Hence the system is highly efficient and low-cost.
Mobile phones have become a widespread means of communication. It becomes a part of everyday life with ever more people enjoying the service and extra freedom they provide. It works on the basis of Global System for Mobile Communication (GSM). A subscriber from any systems can access telecommunication services by using a Subscriber Identify Module (SIM) card in a handset suitable for the network on the visited system The Short Message Service allows text messages to be sent and received to and from mobile telephones.
The text can comprise words or numbers or an alphanumeric combination. Because Simple person – to – person messaging is such an important component of total SMS traffic volumes, anything that simplifies message generation as well as extended utility of the SMS being sent is an important enabler of Short Message Service.
We will connect hardware kit i.e. GSM modem and microcontroller to the energy meter. The main aim of this project is whenever u r recharging with some amount say example Rs.100/- by doing SMS to the MODEM, the bulb gets automatically ON until your recharge gets zero. After getting your balance zero your device gets automatically switched OFF and you will get a message from the MODEM that you have to recharge your mobile and the process takes place continuously.
- AT command supporting GSM mobile phone.
- 89c51 Microcontroller
- Max 232 IC.
- DB9 Connector
- GSM Phone
1. Keil u-Vision
Keil Software is used provide you with software development tools for 8051 based microcontrollers. With the Keil tools, you can generate embedded applications for virtually every 8051 derivative. The supported microcontrollers are listed in the µ-vision.
2. PRO51 Programmer Software