#avr Logs

Jan 31 2019

07:33 AM logithack: i'm fiddling around with timers on an ATTiny261. the interal clock runs at 8 MHz. i've read that when using a /256 prescaler and setting OCR = 0x7A11, youll get an exact 1000ms period. however, 0x7A11 is 31249 decimal, and 8,000,000/256 = 31,250. wouldnt that mean i would have a deviation of 1 clock each time?
07:38 AM [1]MrMobius is now known as MrMobius
08:07 AM [1]MrMobius is now known as MrMobius
08:20 AM day: logithack: you are nowhere near of 1hz precision
08:22 AM day: that being said, that shouldnt matter when it comes to your math
08:53 AM skz81: logithack, that's the classical << boundaries vs interval >> problem.
08:54 AM skz81: If you count from 0 to 255, it takes 256 steps
08:54 AM skz81: so if compval is 255, you will divide freq by 256
09:24 AM pepijndevos: On a atmega328, is any harm done by writing bits to PORTC that are used for I2C and reset?
09:25 AM LeoNerd: What sort of harm would you imagine?
09:26 AM pepijndevos: LeoNerd, well, not harm... but would it interfere with I2C and reset?
09:27 AM pepijndevos: I suppose this is ok? PORTC = value & 0b1111;
09:27 AM LeoNerd: Unless reset is disabled by the fuse whose name escapes me at the moment, PC6 doesn't do anything
09:27 AM LeoNerd: The TWI peripheral, if enabled, overrides the port control anyway. If not enabled those pins are just regular GPIO
09:27 AM pepijndevos: cool
09:44 AM vmt: the fuse is, intuitively enough, "RSTDISBL"
09:44 AM vmt: who'd have thought.
09:50 AM horohoro: hello everyone
09:52 AM nohit: hello
09:56 AM LeoNerd: vmt: Yeah; I could recall it's "reset disable" with some of the letters removed, I can just never remember exactly which
09:57 AM LeoNerd: It's *almost* all the vowels, except "I" gets to remain
10:55 AM cehteh: LeoNerd: what happens on your 328pb board when i powers them with 5v externally and plug usb w/ 5v in?
10:58 AM cehteh: do i need to cut some trace?
11:41 PM day_ is now known as day
11:47 PM gsi__ is now known as gsi_