#avr Logs

Sep 01 2021

03:17 AM specing_ is now known as specing
04:31 AM gogo2464: hi
05:05 AM nohit: hi
05:32 AM exp: hi
07:11 AM exp: boy finding 28V+ high side switches with current limiting is difficult at the moment, there are effectively no good candidates remaining
07:11 AM exp: a few horribly large ones designed for serious loads, but not much in the ~2A class
07:11 AM exp: damn you supply shortage
07:18 AM Thrashbarg: yeah :/
07:21 AM twnqx: tell me about it
07:22 AM twnqx: drams: postponed by a year
07:22 AM twnqx: voltage supervisors: postponed by a year
07:22 AM twnqx: GSM modems: on allocation, maybe a quarter of the order 4 month later
07:22 AM Thrashbarg: yeah it's a large part of why I lost my job too
07:22 AM twnqx: :/
07:23 AM Thrashbarg: can't make things if there's nothing to put together
07:23 AM twnqx: shop had to close down?
07:23 AM Thrashbarg: yea
07:23 AM twnqx: yeah, our assembly house told me they have to do these calls daily
07:23 AM twnqx: CEOs nearly crying on the phone
07:23 AM Thrashbarg: yeah
07:51 AM gogo2464: hi
07:54 AM exp: twnqx: i've stocked up enough for our small volume orders thankfully
07:54 AM exp: but for everything we're farming out, there's almost nothing
07:54 AM twnqx: by now i have everything but the modems
07:54 AM exp: having to swap out all pmics on an older product
07:55 AM exp: my options for the 28v supply are pretty much: just stick a random FET in the way and use a PTC for current limiting
07:55 AM twnqx: discussing with chinese companies about old stockpile last made in '17
07:55 AM exp: back to the electronic ghetto
07:55 AM twnqx: pffff use a pure current limiter
07:55 AM exp: a thin wire?
07:55 AM twnqx: what was it i used...
07:56 AM twnqx: LTC4368
07:56 AM exp: surge stopper?
07:56 AM twnqx: you could probably use that as a high side switch, too
07:57 AM exp: yes certainly, but they're something like 10x as expensive as the standard part we used :)
07:58 AM twnqx: yeah, i put it on a reference board. noone i saw build something based on it used them :P
07:58 AM exp: check out the TPS2493
07:58 AM exp: used for very similar purposes
07:58 AM twnqx: yeah, i wanted a OV/UV/OC lockout with reverse polarity protectio
07:59 AM exp: oh damn i've just remembered I have some P-FETs I need to replace on that part too
07:59 AM * exp sighs
07:59 AM exp: ah yes, it is the 4368-2 we've used before
07:59 AM twnqx: hm yeah, i need to order our v1.2 (changed modem VR) and V2.0 (same change + different modem)
08:00 AM exp: to avoid an N way supply feeding back to batteries
08:00 AM twnqx: (prototypes yet)
08:00 AM twnqx: we have to keep reengineering shit too
08:00 AM twnqx: we also ran out of money to stockpile parts :X
08:00 AM exp: god that's rough
08:01 AM exp: we're low volume enough that i can drop a few tens of thousands on stockpile
08:01 AM twnqx: well, out inventory exploded to currently 200k
08:01 AM exp: otherwise we'd be so screwed, as our stuff is all niche, low lead time, very specific industrial tech
08:01 AM twnqx: and we can't get THE LAST PART to get fresh money in
08:02 AM exp: the nice thing about this will be when the crisis breaks
08:02 AM exp: and suddenly i can buy a few reels of my favourite switch
08:02 AM exp: and they're 50% off
08:02 AM * exp continues to dream
08:02 AM twnqx: i already told my partners "when this break, we need to instantly stockpile"
08:02 AM twnqx: because for some time we will see waves
08:03 AM twnqx: now: everyone is ordering his parts everywhere at once
08:03 AM twnqx: next: inventories are overfilled, noone orders
08:03 AM exp: exactly
08:03 AM twnqx: then: everyone orders again, nothing is available
08:04 AM twnqx: i am dreaming of being just able to fly to shenzhen again
08:04 AM exp: no thank you, i do not fly well
08:05 AM exp: i would like to stay cooped up in my electronics den and never emerge
08:05 AM twnqx: shenzhen is worth a visit
08:07 AM exp: i can imagine it's quite impressive, but i would probably hate it
08:07 AM twnqx: possibly
08:07 AM exp: twnqx: i may have asked this before, do you P&P in house? or farm that out?
08:07 AM twnqx: we have it done
08:08 AM twnqx: we have an assembly house for that, and normally they also do procurement
08:08 AM exp: we've found only a few that can do low volume acceptably, and their quote times are usually pretty long
08:08 AM exp: currently shipping them ~50 parts on cut tape is not going to be economical
08:09 AM exp: so we're looking hard at just doing it ourselves and farming out only the PCB fab
08:09 AM twnqx: we have it done in germany, there seem quite a few around, but most prefer the 1k+ orders
08:11 AM exp: our RF guys use germany too but they have couple month lead times for their orders, as you say
08:11 AM exp: i've put a fair amount through eurocircuits, which are good, but they're not exactly premium
08:11 AM exp: i've had boards arrive with missing solder mask a couple times, nothing that's failed electrical inspection yet though
08:12 AM twnqx: i've got boards from them once... with stopmask over the pads of the main socket
08:12 AM twnqx: and a guy on the phone "but.. it can't work like this!"
08:12 AM twnqx: no shit, sherlock
08:13 AM exp: their ordering interface is much improved now, and i can confirm they do actually do some QC
08:13 AM exp: it's just not as good as it could be
08:14 AM twnqx: i mean, i of course got replament free of charge, because even their board viewer showed no signs of stopmask there
08:14 AM exp: yeah there were a few bugs with their earlier ordering interface so i can totally understand that
08:14 AM exp: they now email you pdfs with their production data so you can triple check
10:57 AM gogo2464: true or wrong: the operand 0x1c alwys represens EECR on ANY architecture of AVR (including atmega328p and more)https://github.com/vancegroup-mirrors/avr-libc/blob/06cc6ff5e6120b36f1b246871728addee58d3f87/avr-libc/include/avr/common.h#L157
10:58 AM gogo2464: the implementation in on the file common. then I think so.
11:06 AM exp: gogo2464: the comment in the file states that is not true
11:06 AM exp: there are parts without EEPROM
02:21 PM gogo2464: thank you exp
02:21 PM gogo2464: I was so busy to reverse that I forgot the comments :)