Barcode reader Problem ?

Printable View

- 16th February 2008, 14:30
iugmoh

Barcode reader Problem ?

Hi all,
If anyone has face this problem to help me,
In my project I have 12V and 5V , 12 volt for driving 12 seven segments and UDN2981 and 5V to drvie PIC16f877a, max7219, LCD, barcode reader (PS/2 ), DS275 and serial eeprom . when I useing only 3 digits of seven segments my project work fine without any problems and the barcode reader working without any problems but when I add 9 digits of seven segments the project is working with all seven segments but I when I insert the id card in the barcode reader it's not working well it's powered on with 5 volt but no response when I insert the ID card , I think that the current is not sufficient to drive the barcode reader , anyone to help me ?

I get 5V from 12V with 7805 regulter
- 16th February 2008, 22:37
Archangel

Quote:

Originally Posted by iugmoh

Hi all,
If anyone has face this problem to help me,
In my project I have 12V and 5V , 12 volt for driving 12 seven segments and UDN2981 and 5V to drvie PIC16f877a, max7219, LCD, barcode reader (PS/2 ), DS275 and serial eeprom . when I useing only 3 digits of seven segments my project work fine without any problems and the barcode reader working without any problems but when I add 9 digits of seven segments the project is working with all seven segments but I when I insert the id card in the barcode reader it's not working well it's powered on with 5 volt but no response when I insert the ID card , I think that the current is not sufficient to drive the barcode reader , anyone to help me ?

I get 5V from 12V with 7805 regulter

Hi iugmoh,
7805 is a 1 amp regulator, if you exceed 1 amp it gets hot and ... also is your 12v supply big enough to supply everything? Have you disabled brown out detect in your config fuses?
- 17th February 2008, 17:51
iugmoh

Quote:

Originally Posted by Joe S.

Hi iugmoh,
7805 is a 1 amp regulator, if you exceed 1 amp it gets hot and ... also is your 12v supply big enough to supply everything? Have you disabled brown out detect in your config fuses?

thanks Joe ,
Oky I solve this problem by adding a seperate volatage supply only for barcode reader and it's working fine.

but what do you mean by "Have you disabled brown out detect in your config fuses"
- 17th February 2008, 17:51
iugmoh

Quote:

Originally Posted by Joe S.

Hi iugmoh,
7805 is a 1 amp regulator, if you exceed 1 amp it gets hot and ... also is your 12v supply big enough to supply everything? Have you disabled brown out detect in your config fuses?

thanks Joe ,
Oky I solve this problem by adding a seperate volatage supply only for barcode reader and it's working fine.

but what do you mean by "Have you disabled brown out detect in your config fuses" ?
- 17th February 2008, 22:16
Archangel

The PIC has the ability to sense when it's power is getting too low and it shuts down if brown out is enabled, if disabled it will run until it won't run any longer . . . so in your config statement you can enable or disable. Some chips use BOD_OFF or BODEN_OFF, you can see all the choices for the chip you are using in the MPASM directory\ xxFxxxx.inc file, the xxFxxxx being the number of the PIC you are using I. E, 16F628A or 16F876A etc. You will find those files in C:\Program Files\Microchip\MPASM Suite\ if you did not use a "custom" install location.
From that file on my computer, p16F877A.inc : _BODEN_OFF added to your config statement will disable brown out detect.
Study this link : http://www.picbasic.co.uk/forum/showthread.php?t=543
- 18th February 2008, 20:25
iugmoh

Quote:

Originally Posted by Joe S.

The PIC has the ability to sense when it's power is getting too low and it shuts down if brown out is enabled, if disabled it will run until it won't run any longer . . . so in your config statement you can enable or disable. Some chips use BOD_OFF or BODEN_OFF, you can see all the choices for the chip you are using in the MPASM directory\ xxFxxxx.inc file, the xxFxxxx being the number of the PIC you are using I. E, 16F628A or 16F876A etc. You will find those files in C:\Program Files\Microchip\MPASM Suite\ if you did not use a "custom" install location.
From that file on my computer, p16F877A.inc : _BODEN_OFF added to your config statement will disable brown out detect.
Study this link : http://www.picbasic.co.uk/forum/showthread.php?t=543

Thanks for your replying

Oky I discover strange problem in my code and I don't know what is the reason , The interrupt woking properly without any problems but when I define new variable like this

qcount var word

any name not necessary to be (qcount) , then the interrupt not woking well , what may be the the cause of this problem ????