Timeline for PIC 12F675 with wrong timing
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 6, 2019 at 6:19 | comment | added | Heath Raftery | 1.5% error sounds okay, if not great, for an internal oscillator. To get better than that I think you'd have to move to an external crystal. | |
| Jun 6, 2019 at 0:02 | vote | accept | Anonymous | ||
| Jun 5, 2019 at 23:10 | comment | added | Anonymous | Ok, I think it is the best I can get out of this chip. I have three: one has calibration byte 1C, another 28, and last one 24. | |
| Jun 5, 2019 at 22:52 | comment | added | Anonymous | It seems have improved the situation: now it outputs 132.93 ms instead of 131.07 ms, and 36.91 ms instead of 36.36 ms. Well 1 ms is 1000 us, equal to 1000 instruction cycles, and this amount is not there for sure. Thus clock is still not much accurate. Is it normal? I used hair dryer to heat the chips, and frequency increased just a little, I do not see much drift. | |
| Jun 5, 2019 at 21:55 | comment | added | Bruce Abbott | Relevant info is on page 2-16 of DS33023A. To load the calibration value you must do call 0x3ff followed by movwf OSCCAL in your startup code (in bank 1). | |
| Jun 5, 2019 at 21:51 | comment | added | Anonymous | Changed config to CLKOUT, and see 1.22 MHz on GPIO4 :( Will dig further. I am afraid I corrupt BG bits, but it is not clear what exactly do they affect. Also, programmer says "OSCCAL: 341C", not sure what that means and where this value came from. | |
| Jun 5, 2019 at 21:35 | history | answered | Heath Raftery | CC BY-SA 4.0 |