#robotics Logs

Jul 10 2021

01:46 AM rue_mohr: hmm how do I resize a rectangle in kicad?
03:09 AM srk: try opengl mode, iirc it's easier there
04:01 AM rue_mohr: routing BGAs is interesting
04:02 AM rue_mohr: oo I wonder if I could do this on just 2 layers
04:22 AM rue_mohr: hahahah
04:23 AM rue_mohr: fringe lesson, they skip letters on the bga grid
04:23 AM rue_mohr: namely, IOQS
04:23 AM rue_mohr: so the edge of a 16x16 bga is not P, its T
04:23 AM rue_mohr: hahaha
04:37 AM Tom_L: hu?
04:43 AM rue_mohr: yea, bga grids skip the letters i, o, q, and s
04:43 AM rue_mohr: its not just h i j k l m ...
04:51 AM rue_mohr: its h,j,k,l,m,n,p,r,t
04:51 AM Tom_L: goin for it ehh?
04:51 AM rue_mohr: I end up with 53 io
04:51 AM Tom_L: how wide are the traces gonna be?
04:51 AM rue_mohr: smol
04:51 AM rue_mohr: smaller than I can do
04:51 AM rue_mohr: but osh should be fine
04:51 AM rue_mohr: 1mm bga is huge
04:51 AM rue_mohr: and I'm only pulling off the outside signals
04:51 AM Tom_L: why?
04:51 AM rue_mohr: so I dont need to do squeezing
04:51 AM Tom_L: you don't need the inner ones?
04:51 AM rue_mohr: I have to anyhow, cause of power pads, but it reduces is quite a lot
04:51 AM rue_mohr: besides, I dont need THAT many io for anything
04:51 AM Tom_L: so you say
04:51 AM rue_mohr: I need the thing more for its internal size than its io
04:51 AM Tom_L: what is it? a fpga?
04:51 AM rue_mohr: cpld
04:51 AM rue_mohr: xc95288xl
04:52 AM rue_mohr: it'll probably get divided down to slow things
04:52 AM rue_mohr: I'll use a dip14 osc module
04:52 AM rue_mohr: and put it in a socket
04:53 AM rue_mohr: 32?
04:53 AM Tom_L: where's pin 1?
04:53 AM rue_mohr: 48?
04:53 AM rue_mohr: pin A1?
04:53 AM rue_mohr: its in the corner
04:56 AM Tom_L: i can hear the wind already
04:56 AM Tom_L: gonna be a windy day
04:56 AM rue_mohr: weather will change then, you can get some sun
04:56 AM rue_mohr: ok, going for 48 io
04:57 AM rue_mohr: kicad is a piece of work to get used to
04:57 AM rue_mohr: their not good at user i/f
04:57 AM rue_mohr: press m to move something, but click to put it down
04:57 AM rue_mohr: m wont put it down again
04:58 AM Tom_L: 40% chance of rain by 6
04:58 AM rue_mohr: I think i see why people use net labels instead of wries
04:58 AM Tom_L: only 86 today
04:58 AM rue_mohr: this will get stupid
04:58 AM Tom_L: yeah?
05:10 AM rue_mohr: it tries to auto-scroll, which is always unwelcome
06:06 AM rue_mohr: mmm never done power planes before
06:06 AM rue_mohr: I think I should do this as a 4 layer
11:08 AM Tom_L: rue_mohr, top is one, bottom is the other, signals inbetween
11:08 AM Tom_L: usually top is gnd (i think)
11:18 AM rue_mohr: I'd be better off to make the middle ones power here
11:18 AM rue_mohr: atleast not he top
11:19 AM Tom_L: better noise immunity
11:20 AM rue_mohr: yea, I cant route power around everything tho
11:20 AM Tom_L: sure you can
11:20 AM Tom_L: ever hear of thru holes?
11:21 AM rue_mohr: I used the outside pins specifically so I didn't have to route them thru the board
11:21 AM Tom_L: run horizontal traces on one layer and vertical on the other
11:21 AM Tom_L: it's a whole new world out there when you don't gotta etch it yerself!
11:22 AM rue_mohr: :)
12:20 PM Tom_itx is now known as Tom_L