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kiranmayi
kiranmayi • Jan 19, 2007

Microcontroller project:suggestions required!

hi everyone
im doing a project on atmel microcontroller(at89c51)

the aim of the project is to sense the ambient temperature using lm35, digitize the data using adc0804 and then display the temperature on LCD. also when the temperature exceeds a certain threshold a warning message is displayed on the LCD's second line.

if u have any suggestions or useful links regarding this project please do reply

thanks in advance:smile:
Hi kiran mayi!I think i can help you. Have done same sort of project with respected N.G.Palan!Ok, I will tell you what i have done,The project was about sensing the physical parameters in plants like tempreture,level etc and sending the status through GSM on the cell of the engineer.This was not it we had a display for the control room on the PC as well as LCD.Temperory shifting of set point if the thresholds were crossed could be done so as to avoid accidents.Then the engineer would go to the site and control the thing manually.
This project can be used to control the household machinery when at workplace. Imagine washing clothes from office! or for that matter making a good snack in your microwave while you return home and relish on it on reaching home! amazing isn't it?
Now i suppose you require some litreture so that you get your basics clear.So for 8085, i would reccommend 'mazjidi'.It's 'The best' book i have come across. It's simplicity makes it special.For lm35 you need to go through the data sheets that will be easily available in your labs! For ADC0804 you can refer N.G Palan's book. Hope this will suffice.If you have any query do let me know i will help you as much as i can.
P.S The names mentioned in the above txt are authors,Got to find the books name!
hemant
hemant • Mar 28, 2007
i need a solution in week plzzz

i m interfacing gsm modem to my microcontroller.i need to send sms
through it.
i am using AT commands for that.the command to send sms (AT+ CMGS)
terminates with
ctrl-Z.now in my program i hav tried all ways to send ctrl-Z at end of
my sms.but it takes this as
a character or string only.also i tried with ascii value of ctrl-Z but
of no use.

i am able to see the transmitted commands on hyper-terminal through
serial interface & also on serail window while debugging.
the commands are as follows with 2ms delay between each of them.

AT ,, AT+CMGS = mobile no. , "message to be sent " ctrl-Z



plz suggest some way.suggestions are also invited if you suspect some
other problem .
hemant
hemant • Mar 31, 2007
i m interfacing gsm modem to my microcontroller.i need to send sms
through it.
i am using AT commands for that.the command to send sms (AT+ CMGS)
terminates with
ctrl-Z.now in my program i hav tried all ways to send ctrl-Z at end of
my sms.but it takes this as
a character or string only.also i tried with ascii value of ctrl-Z but
of no use.

i am able to see the transmitted commands on hyper-terminal through
serial interface & also on serail window while debugging.
the commands are as follows with 2ms delay between each of them.

AT ,, AT+CMGS = mobile no. , "message to be sent " ctrl-Z
please help me
xheavenlyx
xheavenlyx • Apr 1, 2007
Have a look at the AT command set of your particular transmitter/receiver from online manuals. For example Sony Erricson mobiles have many extra AT commands to communicate with the mobile through bluetooth or cable.

The GSM modem's website will have the command set you are looking for. If you cant find a terminating command then look for examples where people have sent sms's, you just need the terminate (CTRL + Z) command.
Asif Siddique
Asif Siddique • Jul 31, 2010
hi!
I have a project in which I am using AT89C52 and ADC0804, but I have a query, what is the the basic difference among ADC0801/0802/0803/0804?
These all seem much like , please reply me as soon as possible because I have no much time left for VIVA (Presentation on project).
Thanks.
Harshad Italiya
Harshad Italiya • Aug 3, 2010
Re: i need a solution in week plzzz

hemant
i m interfacing gsm modem to my microcontroller.i need to send sms
through it.
i am using AT commands for that.the command to send sms (AT+ CMGS)
terminates with
ctrl-Z.now in my program i hav tried all ways to send ctrl-Z at end of
my sms.but it takes this as
a character or string only.also i tried with ascii value of ctrl-Z but
of no use.

i am able to see the transmitted commands on hyper-terminal through
serial interface & also on serail window while debugging.
the commands are as follows with 2ms delay between each of them.

AT ,, AT+CMGS = mobile no. , "message to be sent " ctrl-Z



plz suggest some way.suggestions are also invited if you suspect some
other problem .
Which GSM Modem are you using?
Harshad Italiya
Harshad Italiya • Aug 3, 2010
Asif Siddique
hi!
I have a project in which I am using AT89C52 and ADC0804, but I have a query, what is the the basic difference among ADC0801/0802/0803/0804?
These all seem much like , please reply me as soon as possible because I have no much time left for VIVA (Presentation on project).
Thanks.
Welcome to CE Asif,

please Start new thread for your query.

Regarding your question.. do you have read the datasheet for the ADC080X? if not then please read it. i am sure you will get your answer as they are describing everything in datasheet and you also get some more detail that how to interface it with controller and many more.. just give it one try.
xheavenlyx
xheavenlyx • Sep 9, 2010
ADC0803/4 are one of the best ADC's to use in home projects.
Here is the data sheet for ADC0803 and ADC0804 in the same file. https://www.ece.rochester.edu/courses/ECE216/ADC0804LCN.pdf

The main difference between 803 and 804 is the LSB error. The values are

+/- 1/2 LSB for 803
and +/- 1 LSB for 804

Now what does LSB mean? In simple terms about working of a ADC is that the analog voltage change is represented by a change of bit(s) (which is your digital output). And the minimum change in voltage required to guarantee a change in the output code level is called the LSB (Least Significant Bit).

For much clearer information read this: ADC and DAC Glossary - Maxim

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