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December 18, 2010 at 6:45 am in reply to: LCD based sound operated display using 8051 microcontroller (AT89C51) #5219dagakshayParticipant
Plz elobrate your project a bit more.
dagakshayParticipantthe link i had given you above… i had shown interfacing for one IR pair same way you can do it for other two and its upto you, where you want to interface. just write your code according to that.
just go for the links below the ir interfacing is very beutifully explained.
http://www.engineersgarage.com/electronic-circuit/infrared-ir-sensor
http://www.engineersgarage.com/microcontroller/8051projects/distance-measure-IR-ADC0804-AT89C51
dagakshayParticipantlet me take nokia 7210. or nokia 5233 how to connect these to terminal……
dagakshayParticipantMy dear kunal kalra………
the TTL o/p itself is a digital o/p you can feed it directly to controller
now practically implement it
dagakshayParticipanti din’t get you want circuit for interfacing of sensor pair with microcontroller or circuit of IR sensor to to get TTL o/p….
for ir sensor i had given you above.. i had shown it for one ir pair…..
and for microcontroller interfacing… connect the TTL o/p to one the port(in your case port3)…
reffer to this link
http://www.engineersgarage.com/electronic-circuit/infrared-ir-sensor
dagakshayParticipanta good quatily of IR can give TTL o/p but again at the end the o/p is feed to buffer(say uln2003) to sharp your o/p.. let me expalin this
when ir falls on Rx its conductivity changes, which in turn changes the resistance and we measure the change in voltage. the change in resistance depends on two thing first the amount of IR and second the quality of Rx.
it you have a good quality of IR pair its Tx and Rx efficiency will be higher so it will be able to give TTL o/p but at the end we can be reliable on it. reliable i mean to say it might change voltage from 0-2.5V but micro controller can’t understand 2.5V so we use a buffer at the end.
see the CKT below:-
i tested it and it works, but again you must have a very good quality of IR pair.
the o/p quality also depends on surrounding environment.
dagakshayParticipantit depends on controller to controller…
like at89s51 operating range 4.0v-5.5v
so it is obvious it cant hold 17 to 18 Volts…..
December 5, 2010 at 7:40 am in reply to: assembly language programming for digital thermometer? #5188dagakshayParticipantuse the c code given on the site…. compile it on keil… it will converte it into assembly…..
dagakshayParticipantare you asking about time2 in autoreload mode in at89s52???
plz be a bit more spicified…..
dagakshayParticipantthe IR interfacing shown below gives the analog o/p and so for that there can be two ways to IR sensor with interface 8051
either this analog o/p can be given to ADC and then it is interfaced with 8051. this par is expalined on site. go for the link
http://www.engineersgarage.com/microcontroller/8051projects/distance-measure-IR-ADC0804-AT89C51
or to convert its analog o/p to ttl logic use opamp ion compartor mode….
see the comparator ckt below… and for your application it will be more easier, less complex and cost effictive
…………………………..
dagakshayParticipantthis topic with vedio code adn detailed expalination is given on this site
go for the link:
http://www.engineersgarage.com/microcontroller/8051projects/interface-serial-eeprom-24c02-AT89C51
dagakshayParticipantfor i2c code in 8051 using c is very betufully used in the interfacing of EEPROM on this site (check the link)….. you might get help from that…
http://www.engineersgarage.com/microcontroller/8051projects/interface-serial-eeprom-24c02-AT89C51
dagakshayParticipantthe code must work it might be soome loose connection in the the circuit… what extaclly you getting on LCD.. i mean your LCD is fully blank, or some boxes in first line… or the back light of LCD is not glowing at all…
have you used variable resistance??… it is use to set the contarst… try to set that….
plz be a bit more specify about your problem so that i can help you out….
dagakshayParticipantand for key pad the number of projects mwith codes and vedio are given on this site just go for search option(top right corner)
dagakshayParticipantbelow given is the interfacing circuit for 8051 and stepper motor
use ULN2803 as a buffer in b/w
give a sequence of pin input, set one pin at a time with a particlusr delay.
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