#avr Logs

Oct 07 2021

04:41 AM specing_ is now known as specing
08:39 AM rue_bed: why not isp, you can turn isp off via isp
08:39 AM rue_bed: you might need to inject a clock for it to work tho, depending
04:41 PM specing_ is now known as specing
07:45 PM c4017w_: I'm trying to implement a UPDI programmer. Is there any documentation of the protocol?
07:46 PM LeoNerd: Yes. in the datasheet of every UPDI-talking chip
07:46 PM LeoNerd: And also at least two opensource implementations... pypudpi and my own, Device::AVR::UPDI
07:46 PM LeoNerd: Though to be honest I'd suggest just use any ol' USB-UART bridge and a 1k resistor. There, now you have a UPDI programmer
07:49 PM c4017w_: ah I thought it'd be in a separate app note but couldn't find it
07:50 PM c4017w_: Have to bit bang in for a specific micro
07:51 PM LeoNerd: The AVR chips are selfcontained docs.. one big file that at least doesn't reference others
07:51 PM LeoNerd: Why do you need to bitbang it?
07:51 PM LeoNerd: It's just regular async serial
07:52 PM c4017w_: Well the initialization part anyway. Haven't gotten it to enter UPDI mode reliably yet
07:52 PM qu1j0t3: perhaps c4017w_ is using a uart-less avr
07:52 PM LeoNerd: Oh, for that you just pull it in a long break
07:53 PM LeoNerd: On PC side I do that by temporarily setting the baud rate as low as it'll go (300) and send a "\0"
07:53 PM LeoNerd: That's much longer than a regular word time, so it appears as a break
07:54 PM c4017w_: I was going off the crappy notes of the guy that implemented this previously and was more or less trying things with no reason
07:55 PM LeoNerd: I'd suggest starting with an impl known to work
07:55 PM LeoNerd: E.g. mine, which has worked on every ATtiny 1-series, ATmega 0-series and AVR DA chip I have tried it against
07:55 PM LeoNerd: :)
07:57 PM LeoNerd: Also, if you happen to be using the very small ATtiny412 as your target chip, I've observed that one in particular seems to have a weird silicon bug in the UPDI hardware.. it sometimes doesn't initialise properly
07:57 PM LeoNerd: But anything else larger seems fine
07:58 PM c4017w_: yes, may be better to start with something better documented than this crap...
07:59 PM c4017w_: its a attiny1616
07:59 PM LeoNerd: A nicely reliable chip in my experience. Even if it's a pain to solder
07:59 PM c4017w_: anyway, project for tomorrow. Thanks for the infos
07:59 PM LeoNerd: So tiny... I quite often bridge them
07:59 PM LeoNerd: :)
07:59 PM LeoNerd: Happy to give you more pointers tomorrow then
10:31 PM jmiehe1 is now known as jmiehe