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Microcontroller and database

Discussion in 'Microcontrollers' started by ymnraf, Aug 26, 2005.

  1. ymnraf

    ymnraf New Member

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    Hello all,

    I am a newbie to microcontrollers and i was looking into building an embedded device that has a microcontroller, a memory (probably EEPROM or flash memory) and an LCD display. The microcontroller will take the input from the input system, get the corresponding record from the database, and display the output on the LCD. I was hoping someone here would be able to help me with chosing the best devices for this job (i.e. what models of microcontroller, memory and LCD display are best for such a job). The database is a big one, so I would probably need at least 2megs of memory.

    Thanks.
     
  2. Joel Rainville

    Joel Rainville New Member

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    Are you sure a microcontroller is the right tool for the job?

    Where will that database be located? Are we talking network access to a database with some sort of buffering/caching on the microcontroller?

    Or is your 2MB requirement actually the amount of memory needed on the microcontroller itself (or external RAM/EEPROM on the same circuit) to store all of the data?
     
  3. ymnraf

    ymnraf New Member

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    The 2MB is actually the microcontroller itself (or external RAM/EEPROM on the same circuit) to store all of the data. I am actually not sure if a microcontroller is what I want to use for this but it seems like a microcontroller can do the job. I would appreciate any suggestions or links to helpful sites on such designs.

    Thanks

    rafat
     
  4. dave

    Dave New Member

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  5. Joel Rainville

    Joel Rainville New Member

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    Ok, I think the use of the word "database" is confusing me here...

    It seems that since you are able to put a number to your memory requirements, this will be more like a big table lookup system.

    Or will the interface accept input that should be stored in the DB?

    We need more details on the design and application you got in mind...
     
  6. ymnraf

    ymnraf New Member

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    Hello joel, thanx for the reply, i guess what i wanted to say is a table lookup system. so if the input is 1, the microcontroller will lookup the record with number 1 and output the contents to the LCD. I hope this makes things better.

    Thanx alot!

    rafat
     
  7. ChArLyZzZ

    ChArLyZzZ New Member

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    what do u want exactly?
    * what components do u need?
    * the design
    * software

    please specify but i dont think it's lot complicated
     
  8. ymnraf

    ymnraf New Member

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    Hello Charlyzz,

    I dont think its complicated either. I know the idea but i dont know what exact components to use. I think what i would need is a microcontroller, a memory containing a table, and an output device (i.e LCD screen). I need to give an input to the microcontroller, it will then perform a table lookup and print the output on the LCD. for example, lets say the table contains the following:

    1 Apple

    2 Orange

    3 Banana

    If i input 2 to the microcontroller, it will go perform a table lookup and then print "Orange" on the LCD screen.

    I hope this information make it clear. I just need some guidance towards which components i should look into (i.e models and manufacturers) and where can i find code examples for such functions (and in which language).

    Thank you
     
  9. Someone Electro

    Someone Electro New Member

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    Ok use I2C or SPI EEPROMs.Since parallel EEPROMs need a lot of pins to be interfaced.8 pins alone for data transfer then 12 pins for adress(4K EEPROM) and 3 pins to controle the chip.Whith I2C you only need 2 pins to do evrything.(3 for SPI)

    Then you need an Matrix keypad to enter thew numbers.This takes up 6 pins while it can share 3 pins whith the LCD.So we need 8 pins for the LCD(4 bit mode) + keypad.

    So an 18 pin PIC cod do the job.
     
  10. ChArLyZzZ

    ChArLyZzZ New Member

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    well i guess "Someone Electro" has done the job..in fact that's all what you need regarding the hardware...PIC + EEPROM + LCD
    for the EEPROM, u can go for the 24LCXX series supplied by microchip
    as for the PIC, it depends on how much I/O u need and it should have a built in I2C module..I would suggest PIC16F876A.
    As for the software, you can find lot on the net for the I2C, keypad & LCD...Nigel's website will help u a lot
    good luck
     
  11. gregmcc

    gregmcc Member

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    Someone Electro: You say that a keypad takes up 6 pins and it can shares 3 pins with theLCD. How do you go about doing this?

    I'm starting to build a project using a lcd + keypad and will need a few other ports so need to save pins.
     
  12. ymnraf

    ymnraf New Member

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    Thanx alot everyone, the information you gave me was useful in getting me started, i will go through my research and my project and will come back with any questions I might have later. This forum is great!

    Thanks again,
     
  13. Someone Electro

    Someone Electro New Member

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    The LCD dosent even bother looking at its Data I/O bus if the PIC dosent tell it that it wants o send somting.So you just stop scaning the keypad wen data needs to be sent to the LCD.This can save some pins.

    But it wod probobly be beter not to share pins becose you probobly have emtpty pins left.

    This is a trick if your runing low on pins.
     

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