Voltage monitor for car’s battery and its charging system | Anna university questions papers projects for EEE,ECE,IT,MECHANICAL,MBA,MCA Anna university questions papers projects for EEE,ECE,IT,MECHANICAL,MBA,MCA: Voltage monitor for car’s battery and its charging system Bank Exam question paper, GATE Papers,Combined Defence Service Examination papers ,TANCET,BSNL JTO,ISRO,EBOOKS,DRDO ,BARC, , NTPC ,BHEL ,BEL ,HAL,Anna University Papers,ECE , EEE , CSE , IT , Mech , BIOMEDICAL , Textile , MBA , MCA , Anna University Question Bank , Anna University Syllabus , Anna University 'Q' Papers , Gate Papers , 8051, AVR, 8051 projects, free 8051 microcontroller projects, AVR projects, AVR tutorial, AVR microcontroller projects, circuits, hobby electronics, microcontroller based projects, microcontroller projects, final year projects, electronic projects, electronics projects, circuit diagrams, pin diagram, pin description, interfacing with AT89C51, 8051 tutorials, embedded projects, serial port, sensor, Electronic Components, Electronic Circuits, circuits for hobbyist, electronic schematics, DIY projects, breadboard circuits, at89c51, 8051 code, advanced circuits, hobby projects, circuit ideas, embedded system, embedded C, microcontroller programming in C, LCD interfacing, ADC interfacing, circuit components, hobby circuits, seven segment display, 89c51 projects, circuit description, major projects, minor projects, projects for circuit branches, interrupt, 8051 programming, RS232, 8 bit microcontroller,Microcontroller Tutorials, PIC Tutorial, 8051 Microcontroller Tutorial Resource, Connect to the PIC, PIC Tutorials, Micro Controller Tutorials, PIC Micro controller Tutorial Resource, DALLAS 80C320, DS80C320, Connect to the PIC, PIC Tutorials, Dallas DS80C320, 8051 Introduction, Types of Memory, Special Function Registers, Basic Registers, Addressing Modes, Program Flow, Low Level Information, 8051 Timers, 8051 Serial Port Operations, 8051 Interrupts, Additional Features of 8052, 8052 Instruction Set, Computer Science Seminar Topics, Mechanical Engineering Seminar Topics,Electrical Seminar Topics,Electronics Seminar Topics,Seminar Abstract And Report Downloads,High-Speed Architecture, New Instruction Speed, Variable Length MOVX Instruction, Timer Considerations, Dual Data Pointer, Watchdog Kicking, The Watchdog Watchdog Interrupt, Watchdog System Resets, Power Failure Functions, Power Failure Reset, Power Failure Interrupt, Secondary Serial Port, Timed Access Protection, PIC16F877A Tutorial, Introduction to the PIC16F877A, How to hook up the PIC so it will run?, What do the pins mean?, How to program the PIC?, Miscellaneous Advice, LED Blinker, Photoresistor Input, Analog Input (Photoresistor, Sonar sensor, IR sensor, Digital Input (Switches), Output messages to computer screen, Servo Motor Output, DC Motor Output,Gate sample paper with solution , Engineering E-Books , Free ebook websites , Final Year Projects , Placement papers,anna university previous year question bank, previous year question paper,model question paper, two mark question paper,sex,adult,results,atmel humidity Assembly Language code, Digital Clock Employing Memory Mapping, Humidity Sensing, Microcontroller51,control solid state relays, decoded 74ls138, latech 73ls373, port expander, Solid State Relays,urn ON, turn OFF, Relay Driver, back EMF, holding, current, pullup, resistor, coil, BC547, ULN2003, ULN2803, npn, transistor, microcontroller, Technology, circuit,bharathidasan university,university,thanjavur,madurai,coimbatore,chennai,adult,porn,sastra,sastra university, placement and training cell,java,j2ee,ajax,c,c++,oracle,COMPUTER SCIENCE,embedded, embedded systems, j2ee, dotnet, j2me, dot net, jsp, vb, c#, c, c sharp, computer science, cse, information technology, it, Electrical, Electronics, communication,SURVEY,ONLINE JOB,PAY TO CLICK,SEBOSA, ece, eee, academic, college, instrumentation, control, control systems, best ,project centers, project centres, company, companies, software, telecommunication, telecom, networking, matlab, robotics, Artificial intelligence, automation, cloud computing, cryptography, data mining, dsp, database, digital, image processing, fuzzy logic, gsm, gps, gprs, mobile computing, networks, network security, php, power, systems, vlsi, hardware, web services, wireless, rf, rfid, microcontroller, ns2, 2010, titles, list, download, latest, free, advanced, low cost, placement, zigbee, Chennai, india, uk, SOFTWARE ENGINEERING, APPLIED ELECTRONICS, VLSI Design, M.E,EMBEDDED SYSTEMS, COMMUNICATION SYSTEMS,Memory Organization, Microcontroller to LCD, moving message display using 8051 microcontroller, MOVING MESSAGE DISPLAY USING ATMEL 89C51, PIN Configuration, Programming Aspects, POWER ELECTRONICS, 89c51, 89s51 moving message display board, microcontroller 8051,8051, AVR, 8051 projects, 8051 microcontroller projects, AVR projects, AVR tutorial, AVR microcontroller projects, electronics projects, free electronic circuits, circuit diagrams, circuits, schematics, hobby electronic projects, electronic projects, hobby electronic circuit diagram, final year projects, embedded projects, technical articles. Interfacing microcontroller 8051 with peripherals like ADC, LCD, EEPROM,solenoid valve atmel dc control triac,dimmer bt138,uln2003 microcontroleur interfacing a microprocessor to a power thyristor microcontrol based level mesurement 89c51 as pwm controller,at89c2051 sine wave pwm,8051 lift, circuit design for a elevator, Elevator Lift control for three stories with microcontroller 8051, microcontroller based lift controller for three stories, three stories lift,ericsson at command microcontroller, GSM/ EDGE Modem in PCI Interface, Interface of mobile phone with micro-controller, Supporting AT commands,embedded projects,8051,pic,arm,pic16f877a,qualifity,best project in thanjavur,relay design,product manufuring,dvd,vcd,service,free training,electrical and electronic circuits,pcb board design,help of embedded,earn money with embedded,part time job,home based job,vacancy,ieee transaction,optimization,website design,university, Chapter 2 Liquid Crystal Display, Character Generator RAM, DDRAM or CGRAM, Display on or off control, LCD, microcontroller interface with LCD, PIN Configuration, Pressure monitoring with microcontroller 8051, Pressure sensing and controlling, Pressure Sensing System, Programmable Peripheral Interface, RS-232 serial communication,diploma in embedded,matlab in thanjavur, seo,site design @2900 onwards, 8255 and RS232, 89s51 LCD display LM 35 ADC0804 measurment, construction of a pressure sensing system using 8051, designed pressure sensor and transducer,microcontroller based heart rate meter,8051 pin diagram,invention heart rate meter,heart meter watch,heart beat monitor project,8051,AVR,8051 projects,free 8051 microcontroller projects,AVR projects,AVR tutorial,AVR microcontroller projects,circuits,hobby electronics,microcontroller based projects,microcontroller projects,final year projects,electronic projects,electronics projects,circuit diagrams,pin diagram,pin description,interfacing with AT89C51,8051 tutorials,embedded projects,serial port,sensor,Electronic Components,Electronic Circuits,circuits for hobbyist,electronic schematics,DIY projects,breadboard circuits,at89c51,8051 code,advanced circuits,hobby projects,circuit ideas,embedded system,embedded C,microcontroller programming in C,LCD interfacing,ADC interfacing,circuit components,hobby circuits,seven segment display,89c51 projects,circuit description,major projects,minor projects,projects for circuit branches,interrupt,8051 programming,RS232,8 bit microcontroller,microcontroller based heart beat monitor,8051 isp programmer,heartbeat monitor and display on LCD,heart beat rate monitor with sensor,training heart rate monitor with comaprators ans sensor,8051 microcontroller application,optocoupler based sensor of runner heart rate monitor,how to measure heart beat, calculate heartbeat just in one second,8051 rtos,limitations of heart rate monitors, quick display of heart monitor,advantages of electronic medical records,electronic medical billing,used electronic test equipment,electronic document management solution,fetal heart rate monitor,wrist heart rate monitor,avr 8051,baby heart monitor,heart beat counter using microcontroller 8051, block diagram for ir led and ldr based heartbeat monitor with display on computer, MICROCONTROLLER AT89C2051 BASED HEART BEAT MONITOR (PULSE RATE wth assembly code),ir led and ldr based heartbeat monitor with display on computer,wireless biomedical monitoring system using 89S52 microcontroller,wireless biomedical monitoring system using 89S52 microcontroller,8051microcontroller based heart beat monitor,heart pulse system project,very cheap cost in india,lm35,temperature sensor,heart beat sensor,technology,solutions,sastra university,data base design,speed ,innovative centre,home security system model design, water level indicator for home,COMPUTER SCIENCE, SOFTWARE ENGINEERING, APPLIED ELECTRONICS, VLSI Design,IEEE Project center, IEEE 2010 Projects in Tanjore, trichy, Kumbakonam, Pudukkottai, Ariyalur, Pattukkottai, Best IEEE Projects, final year projects, Project Center in Trichy, Project Company in thanjavur, Project training @ tanjore, Free 8051 Microcontroller projects,8052 projects,microcontroller,projects, Datasheers,circuit diagram,Microcontroller,8051,AVR,8085 Microprocessor,BASCOM,projects,tutorials,codes,Libraries,interfacing examples,embedded projects,serial port,infrared remote controls,rf remote controls,home automation,Intel 8051 microcontroller,electronic projects,embedded systems,control systems,computers,technical books,software,assembly language,programming intels 8051,serial communications,rs232,Electronics Projects,Books,Home Automation,Computer Software,Assemblers,Compilers,applications Programming,Embedded Systems Design,8052,AT89C2051,robotics applications,visualbasic, Microsoft Visual Basic,system, based, solar, control, intelligent, motor, controller, vehicle, monitoring, pwm, detection, home, temperature, tracking, alert, blind, alcohol, automated, automatic, close,Robotics,Kits,Circuit Examples,8051,Robots,micro Code,AT89c51, Programmer,IEEE 2010 embedded systems, embedded programming, PIC Micro projects, Microchip Programming, AVR tutorials, PIC Micro tutorials, ATMEL, Microcontrollers based systems, Microcontroller Projects, Embedded projects, Embedded designing in C, Microchip Lab, Embedded systems tips, DIY Electronics,Project Detail,onlinejob, Data Entry, no fee, no investment, part time, home based,recuirements,job,consultancy,helpline,maths,power,ultimate knowledge,prodigy,trichy,mobile
100% FAT LOSS TIPS Click Here!

Voltage monitor for car’s battery and its charging system

, Posted by ADMIN at 10:22 AM

My 2010 Equinox has got every feature that a modern automobile should have. However, one thing that I personally find missing is the real-time monitoring of voltage across the car's battery terminals. This may not seem to be that important but one of the most common reasons for a car battery failure is the faulty charging system. If the charging system is not working properly, the battery will not get the proper charging voltage (about 13.8 V for 12V battery) across its terminals and it could go flat. This project is about making a simple electronic voltage monitor system for car's battery and its charging system. It plugs into the car's cigarette lighter receptacle and displays the instantaneous output voltage across the battery terminals on a 4-digit seven segment LED display. This helps you to get early warnings for possible battery and its charging system problems. Microchip's PIC16F1827 is the main controller in this project, which uses the built-in Fixed Reference Voltage (FVR) module to achieve a very precise and accurate A/D conversion of the battery voltage.

Car's battery and charging system voltage monitoring device


As I said this project is simply about making a precise digital voltmeter that plugs in to the car's cigarette lighter receptacle and displays the instantaneous voltage across the battery terminals. When the engine is turned off, the voltage measured by this device is the actual output voltage from the battery. However, if the engine is on or the car is running, it actually measures the charging voltage across the battery that is coming from the car's charging system (alternator + rectifier). The functional block diagram of this project is shown below.

Functional block diagram of car battery monitor system

The +5V power supply for the PIC16F1827 microcontroller circuit is derived from the car's battery output voltage (usually +12V) using a regulator IC (such as LM7805). The battery terminal voltage is measured through an ADC channel of PIC16F1827. The FVR module inside PIC16F1827 is chosen to derive a stable positive reference voltage of 4.096 V for precise A/D conversion. Before feeding to the ADC channel, the battery output voltage is scaled down to below the reference voltage by using a voltage divider network. The measured instantaneous battery voltage is shown on a 4-digit seven segment LED display.

Read my previous article, Using Fixed Voltage Reference (FVR) for A/D conversion in enhanced mid-range PIC microcontroller, to find more information on the FVR module of PIC16F1827.

Circuit diagram

The circuit diagram of this project is shown below. The PIC16F1827 microcontroller uses the AN4 ADC channel for measuring the voltage across the car's battery terminals. The R1 and R2 resistors at the ADC input channel creates a simple voltage divider network to scale down the incoming voltage from the battery's positive terminal. The maximum measurable input voltage at AN4 is 4.096 V (limited by using the internal 4.096 V reference voltage for A/D conversion). Therefore, the maximum input voltage (VBattery) that could be measured without A/D saturation can be obtained from the following equation,

4.096 V = R2*VBattery/(R1 + R2)

Or, VBattery =  16.93 V.

The range of input voltage can be increased simply by lowering the value of R2. The 5.1 V Zener diode is placed in parallel with R2 to prevent the voltage at the microcontroller's ADC channel from going above 5.1 V. Otherwise, any accidental high input voltage could damage the microcontroller port permanently.

Circuit diagram for car battery voltage monitoring device

The measured voltage is shown on a 4-digit seven segment LED display (common cathode). The seven segments (a-g) and the decimal point (DP) are driven through PORTB of PIC16F1827. The microcontroller runs at 500 KHz using the internal clock source. The ULN2003 darlington array provides current sink to each of the common cathodes of the seven segment LED module.


Pin diagram of PIC16F1827

The regulated +5 V supply can be derived from the car's cigarette lighter receptacle (12 V output) using LM7805 regulator IC. However, I preferred to use my spare USB car charger to serve this purpose. The USB port has 4 pins (+5 V, D+, D-, and Gnd). In the car charger, the D+ and D- pins are kind of useless. So I opened my USB car charger, disconnected the output D+ pin from rest of the circuit, and re-wired it to the input +12 V from the battery. Now, we have +5 V, Gnd, battery terminal voltage, and D- (useless) in the USB port pins of the car charger. Then I used an USB-A Male to B Male Adapter to connect these signal lines to the microcontroller circuit board.

Connecting the battery terminal voltage at one of the USB port data pins

Re-wired USB car charger and the USB-A Male to B Male Adapter

Circuit is powered from a USB car charger

Car battery voltage monitor circuit assembled to USB car charger

4-digit seven segment LED display at the front


The firmware for this project was developed in mikroC Pro for PIC compiler. The equations to derive the input voltage from the 10-bit ADC output (Digital Number, DN) are described below.

VBattery = VADC, IN * (R1 + R2/R2) = 4.13 * VADC, IN

Resolution of ADC = 4.096/1024 = 4 mV/DN

VADC, IN = DN * 4 (mV)

=> VBattery = 4.13 * 4* DN (mV) = 0.0165*DN (V)

The use of internal reference voltage for A/D conversion requires configuration of FVRCON and ADCON1 registers. The mikroC Pro for PIC compiler provides a library for A/D conversion, but that uses the supply voltage, VDD , by default as the positive reference for the conversion. So the built-in ADC library of mikroC Pro for PIC is not useful for our case and we need to write our own ADC subroutine. The complete source code for this project can be downloaded from the link provided below.

Download the source code and HEX file


Plug in the device into the car's cigarette lighter receptacle and turn in the car key to on position (don't start the engine). This will display the car battery terminal voltage (about 12 V). Once the engine is turned on, the battery starts receiving the charging voltage from the alternator. This voltage should be higher (about 13.8 V) than the actual voltage produced by the battery itself.

Battery voltage (engine off)

Output voltage from the charging system (engine on)


An additional LED or a buzzer can also be added to the circuit to alarm under (say < 11.8) or over (say >14.0 V) voltage conditions.

With Regards,

sms communication,
Tanjore -1.

mobile :9944 186 173           

Currently have 0 comments: