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Ashutosh BhattParticipant
now try out online tutorials for 8051 available on this site like LED blinking, LCD, key pad, ADC – DAC interfacing etc.
and then move on to small applications
Ashutosh BhattParticipantdont forget to provide fixed value biasing resistor before LDR.
Ashutosh BhattParticipantdear friend
where is the RF protocol?
you have to implement any RF protocol. streight forward serial transmission will not work.
better to use RF encoder-decoder chip like HT12E-HT12D
Ashutosh BhattParticipantRC circuit can not be used to boost voltage level.
if you want to shift DC level of signal from 0 to some other level then simply use positive diode clamper circuit.
Ashutosh BhattParticipantchecking of receive code is very simple
you will get ASCII characters for each letter or digit. like 0x31 for digit 1 0x41 for letter A like wise.
mostly you will get string of such ASCII characters from any device like GSM modem or GPS receiver.
so what you have to do is store this command in string – character type array
then just compare string using strcmp command in C language
Ashutosh BhattParticipantheating of 7805 is normal thing. provide good heat sink to 7805.
Ashutosh BhattParticipantconnect the output of all four sensors with any port in sequence like D0 – D3
check for change in input for this port
find out how many sensors are blocked like for 1 sensor blocked ip is 1000, for two sensors blocked ip is 1100…. (or it can be reversed)
based on this input set a count like for 1000 ip count is 100, for 1100 ip count is 200…
give pulses to motor till count reaches to 0.
thats all
Ashutosh BhattParticipantyou need a DAC for that
you have to give digital input and you get corresponding analog output
for example using 8 bit DAC to generate square wave
first give digital input 00h (all 0’s)
then after delay give input FFh (all 1’s)
again after delay give all 0 input like wiseAshutosh BhattParticipantthere are two interrupts for UART
1) with transmit data
2) with receive data
both have to be saparately enabled or disabled.
one of the best way to test UART with computer is use LOOP BACK mode.
send character from hyperterminal and receive same from controller on hyper terminal screen.
Ashutosh BhattParticipantfor your project you need following interfaces
IIC for RTC
SPI for SD card
USB for PC interfacing
so just go through the datasheets of different PIC controllers and select the best one
this is actually good practice to search for best up/uc/CPU for your application. i suggest to do this excercise every time because it can make things simpler.
not only PIC you may also go for ARM for enhance performance.
Ashutosh BhattParticipanti suggest first you go through the datasheet of SDC with which you are working. try to make interfacing diagram, try to find out logic
we will definately help you if you are going wrong
Ashutosh BhattParticipantyou have not specified which interrupt you want to use
in your program you are enabling external interrupt 0 but your ISR is for timer 0 interrupt (interrupt 1 keyword is for timer 0 interrupt)
also you have not enabled globle interrupt
use IE = 0x81 to enable external interrupt 0
and IE = 0x82 to enable timer 0 overflow interrupt
February 19, 2014 at 4:42 am in reply to: how to interface a rf tranmitter and receiver to microcontroller AT89S52? #11055Ashutosh BhattParticipantyou need encoder-decoder chips and 433 MHz transmitter receiver pairs. but in this case you need some IO port pins to be free to get decoded data.
if you dont have any pins left then two options
1) use FSK transreceiver both sides that can be directly connected to Tx Rx pins
2) use serial bluetooth module at both sides
Ashutosh BhattParticipantin ATmega controllers generating PWM using fast PWM method is easy. for setting frequency you have to divide clock frequency by desire factor. during this time period the ramp increases from min (0) to max (256).
Ashutosh BhattParticipantfirst be familier with 8051 from good books or online material.
then develop and test some sample programs in assembly language and C language on KEIL cross complier.
then switch to hardware development
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