Sign in
Search piclist
Subscribe to piclist
piclist by Keywords
12F675 | 16F628 | 16F84 | 16f877 | 16F877A | 16F88 | 18F458 | ADC | AVR | Bootloader | CAN | CCS | CRC | EAGLE | EEPROM | ICD | ICSP | IDE | JDM | LED | Macros | Microchip | MPLAB | PCB-CAD | PIC10F | Pic12f675 | PIC16F84 | PIC16F84A | PIC16F877 | PIC18 | PIC18F452 | PicBasic | PICC | PICSTART | PWM | RS-485 | RS232 | SMT | SPI | UART | USART | USB | Wireless | Wisp628 | Xilinx
Discussion Groups
Discussion Groups | Piclist | Re: Re: 12F675 Startup Problems
A discussion group for the PICMicro microcontroller. Also called the Microchip PIC, this list is dedicated to the use and abuse of this fine, simple, microcontroller. Close to topic posts are welcome, ie. general electronics.
Re: Re: 12F675 Startup Problems - Eirik Karlsen - Dec 7 22:09:42 2007
Use xtal osc.
One byte is typically 10bits and that means a max drift of +/-5% if the last bit is to be detected correctly
(assuming sampeling in the middle of the bit).
The practical requirement is more like -/+1% for reliable operation. Only a xtal or maybe resonator
can achieve that type of accuracy.
kg4pid wrote:
> To make it work I had to change the the value that gets moved into
> OSCCAL. Since the serial routine that I used had been around awhile
> I can only assume that the problem is in the Pic oscilator. Don't
> know what to do to fix it though as I don't want to have to
> calibrate each pic chip.
>
> Max
--
*******************************************
VISIT MY HOME PAGE:
LAST UPDATED: 23/08/2003
*******************************************
Regards
Eirik Karlsen
(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )
Re: 12F675 Startup Problems - smxcu - Dec 8 12:39:34 2007
--- In p...@yahoogroups.com, Eirik Karlsen wrote:
>
> Use xtal osc.
> One byte is typically 10bits and that means a max drift of +/-5% if
the last bit is to be detected correctly
> (assuming sampeling in the middle of the bit).
> The practical requirement is more like -/+1% for reliable operation.
Only a xtal or maybe resonator
> can achieve that type of accuracy.
>
> kg4pid wrote:
Hi Eirik,
It's actually more like 2.5% and if you look carefully at what you
have written (turn it around) you can get reliable operation if you
decrease the number of bits sent per byte. Remember that this type of
serial comms sends and receives bytes least significant bit first. You
could use a modified character set of 6 or even 5 bits such as one
shown here:
http://homepages.cwi.nl/~dik/english/codes/stand.html
Regards
Sergio Masci
http://www.xcprod.com/XCSB
.
to unsubscribe, go to http://www.yahoogroups.com and follow the instructions
(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )
>
> Use xtal osc.
> One byte is typically 10bits and that means a max drift of +/-5% if
the last bit is to be detected correctly
> (assuming sampeling in the middle of the bit).
> The practical requirement is more like -/+1% for reliable operation.
Only a xtal or maybe resonator
> can achieve that type of accuracy.
>
> kg4pid wrote:
Hi Eirik,
It's actually more like 2.5% and if you look carefully at what you
have written (turn it around) you can get reliable operation if you
decrease the number of bits sent per byte. Remember that this type of
serial comms sends and receives bytes least significant bit first. You
could use a modified character set of 6 or even 5 bits such as one
shown here:
http://homepages.cwi.nl/~dik/english/codes/stand.html
Regards
Sergio Masci
http://www.xcprod.com/XCSB
.
to unsubscribe, go to http://www.yahoogroups.com and follow the instructions
(You need to be a member of piclist -- send a blank email to piclist-subscribe@yahoogroups.com )