12-04-2014, 12:41 PM
Digital fuel level indicator and automatic vehicle speed controller
fuel level indicator.docx (Size: 1.07 MB / Downloads: 36)
INTRODUCTION
OVERVIEW
Intelligent instruments are used in every part of our lives. It won’t take much time to realize that most of our tasks are being done by Electronics. They will perform one of the most complicated tasks that a person does in a day.
As the days of manned driving are getting extremely numbered, so are those of
Traffic jams, dangerous and rough drivers leads to accident. Accidents occur frequently in highways, which will create a heavy loss for the victim’s families as well as for the society. Mainly accidents occur due to the unawareness of the driver about the obstacles that may be present on the highway routes.
Together with this in the recent times we are constantly hearing about petrol bunk frauds. Most of the petrol bunks today have manipulated the pumps such that it displays the amount as entered but the quantity of fuel filled in the customer’s tank is much lesser than the displayed value. The pumps are tampered for the benefit of the petrol bunks owner. This results in huge profits for the petrol bunks but at the same time the customers are cheated. All the vehicles in India consist of analog meters hence it is not possible to precisely know the amount of fuel currently in the vehicle and also it is not possible to cross check the quantity of fuel filled in the petrol bunk. In this project we focuses on creating a digital display of the exact amount of fuel contained in the vehicles tank and also help in cross checking the quantity of fuel filled at the petrol bunk. Finally once the fuel is filled at a bunk the device also sends an SMS to the vehicle owner indicating the quantity, and date etc.
Vehicle speed control and Fuel level detector unit
This unit is fixed in any vehicle. This unit receives the signal transmitted from the zone status transmitting unit and senses the fuel present in the tank of the vehicle. This unit consists of various blocks as mentioned below
RF receiver.
RF decoder.
Micro controller unit.
Fuel level sensor.
GLCD
GSM
Buzzer
RF TRANSMITTER
The RF transmitter and receiver are used both in the control unit as well as in the robotic module. The RF transmitter and receiver in the transmitter and receiver module respectively operate at the frequency of 433MHz and the transmitter and the receiver module in the robotic module and the control unit respectively operate at the frequency of 316MHz.
RF RECEIVER
The RF receiver in the transmitter module receives the distance related information transmitted by the robotic module. The microcontroller is used to display the distance on the LCD module. The receiver in the robotic module receives the control signals transmitted by the control unit which are used to control various functions of the robot. The figure below shows the pin out diagram of the RF receiver.
RF ENCODER (HT12E)
They are 2exp12 encoders are a series of CMOS LSIs for remote control system applications. They are capable of encoding information which consists of N address bits and 12_N data bits. Each address/data input can be set to one of the two logic states. The programmed addresses/data are transmitted together with the header bits via an RF or an infrared transmission medium upon receipt of a trigger signal. The capability to select a TE trigger on the HT12E further enhances the application flexibility of the 212 series of encoders.
RF Decoder HT12D
The 2exp12 decoders are a series of CMOS LSIs for remote control system applications. They are paired with Holteks 2exp12 series of encoders. For proper operation, a pair of encoder/decoder with the same number of addresses and data format should be chosen. The decoders receive serial addresses and data from a programmed 2exp12 series of encoders that are transmitted by a carrier using an RF or an IR transmission medium. They compare the serial input data three times continuously with their local addresses. If no error or unmatched codes are found, the input data codes are decoded and then transferred to the output pins. The VT pin also goes high to indicate a valid transmission.
Memory Organization
There are two internal flash memory blocks in the device. Block 0 has 16/32/64 KB and is organized as 128/256/512 sectors, each sector consists of 128 B. Block 1 contains the IAP/ISP routines and may be enabled such that it overlays the first 8 KB of the user code memory. The data RAM has 1024 B of internal memory. The device can also address up to 64 KB for external data memory.
The device has four sections of internal data memory:
1. The lower 128 B of RAM (00H to 7FH) is directly and indirectly addressable.
2. The higher 128 B of RAM (80H to FFH) are indirectly addressable.
3. The special function registers (80H to FFH) are directly addressable only.
Timers
The two 16-bit Timer/counter registers: Timer 0 and Timer 1 can be configured to operate either as timers or event counters. In the ‘Timer’ function, the register is incremented every machine cycle. In the ‘Counter’ function, the register is incremented in response to a 1-to-0 transition at its corresponding external input pin, T0 or T1. In this function, the external input is sampled once every machine cycle.
When the samples show a high in one cycle and a low in the next cycle, the count is incremented. The new count value appears in the register in the machine cycle following the one in which the transition was detected. Since it takes two machine cycles (12 oscillator periods) for 1-to-0 transition to be recognized, the maximum count rate is 1/12 of the oscillator frequency. There are no restrictions on the duty cycle of the external input signal, but to ensure that a given level is sampled at least once before it changes, it should be held for at least one full machine cycle. In addition to the ‘Timer’ or ‘Counter’ selection, Timer 0 and Timer 1 have four operating modes from which to select.
The ‘Timer’ or ‘Counter’ function is selected by control bits C/T in the Special Function Register TMOD. These two Timer/counters have four operating modes, which are selected by bit-pairs (M1, M0) in TMOD. Modes 0, 1, and 2 are the same for both Timers/counters. Mode 3 is different. The four operating modes are described in the following text.
Graphic LCD Display
The Graphic LCD display used in this project is 128x64 pixels, where it has 128 columns and 64 rows. Supply voltage is 5V matching the voltage for most microcontrollers. The LCD controller is Samsung KS0108B. JHD12864J module uses 8-bit data bus (DB0 – DB7). Nevertheless, it is a straight forward module comparing to other LCD series like T6963C. JHD12864J is split logically in half with controller #1 (CS1) driving the left half of the display, and controller #2 (CS2) driving the right half. These two portions map directly to the physical display area.
Steps to test the GSM Module
First insert the SIM card to the GSM Module.
Connect the Serial cable –RS232 to the PC via DB9 pin connector on the GSM Module.
Give the power supply. The power supply indicating LED will be ON continuously.
Another LED on the Module starts blinking to indicate the availability of network. If the network is available then the delay between the blinking is less. If the network is not available then the delay between the blinking is more.
CONCLUSION
This prototype model consists of RF transmitter and a receiver. RF transmitter placed at signboard, Signal from the sign boards located at different location are encoded and transmitted to a RF receiver placed in the vehicle. The received signals are decoded and information send to microcontroller, buzzer is activated and corresponding code signs displayed in the GLCD with controlling the speed of the vehicle this avoids the accidents and together with this it gives the information about fuel present in the owner vehicle.