How to reprogram the OSC cal. 12F675

[rtsandiego]

Hi All,

I'm doing some work with a PIC 12F675 (programming with a Melabs USB programmer) and accidently erased my calibration values for the internal oscillator. Is there a way to reprogram this? I'm using the standard "beta" software used to interface with the USB U2 programmer.

[LarryZ]

I know if you have another one you can look at the last address which is where it is stored. Then you can store that number in your's
Run a program and see how close it comes to your calculations and then adjust it.

[Melanie]

Hmmm... how much Test Equipment, time and patience have you got???

(1) If you have a Frequency Counter, program for INTOSC CLKOUT and measure fosc/4 on the GPIO.4 OSCOUT pin. Adjust for 1MHz.

(2) If you don't have a frequency counter, SEROUT a Test Message at say 9600 baud to your PC. Keep adjusting the value until sensible data is reliably copied onto say your PC's Hyperterminal.

(3) Save yourself $500 worth of effort, spend $1 and buy yourself a new PIC.

[Acetronics2]

4) IF you have 40 Bucks ... to spend.

Buy a Pickit2 ( or 3 ! with more bucks )

and just hit the " retrieve cal factor" button ...

for the money ... you get an excellent ICSP programmer ...

Alain

[LinkMTech]

(3) Save yourself $500 worth of effort, spend $1 and buy yourself a new PIC.
Oh Melanie,
You and your quick whips are always good for a laugh... thank you