#avr Logs

Mar 17 2022

01:35 AM polprog: Ive once built an entire sample and hold from a 4066 and two opamps
02:09 AM rue_mohr: qu1j0t3, so, how about a transistor
02:09 AM rue_mohr: whats your signal range and supply rail range?
02:12 AM rue_mohr: trust me, your going to love this trick and its going to blow your mind.
05:00 AM specing_ is now known as specing
08:08 AM qu1j0t3: rue_mohr: i've thought a lot about a transistor. signal range is 0..5v , supply rails are -5v and +5v. i know jfets and so on have been used.
08:09 AM qu1j0t3: i guess a mosfet "should" be fine
08:11 AM qu1j0t3: control signal is 5v logic level from mcu
08:26 AM rue_bed2: you can use a bipolar actually
08:26 AM rue_bed2: you need a bit more + headroom tho
08:45 AM rue_mohr: you would want a supply about 7V
08:46 AM qu1j0t3: a lot of my ICs top out at 5.5v unfortunately
04:10 PM ville: howdy. anyone by chance using arch linux and a pololu usb avr programmer v2.1? having some trouble getting my system to even see the programmer. nothing shows in dmesg or lsusb when i plug it in
04:12 PM ville: all i can see is yellow led blinking on the programmer next to to usb connector
04:12 PM ville: any ideas?
04:14 PM nohit: no ideas
04:16 PM nohit: someone will probably have but you need to stick around
04:19 PM ville: also `pavr2cmd --status` returns with "Error: No programmer was found"
04:21 PM ville: hmm think it may be that all my cables are improper kind?
04:26 PM nohit: yeah you should have green led blinking
04:26 PM nohit: https://www.pololu.com/docs/0J67/4.4
04:28 PM ville: tried 4 cables so far and all of them are the wrong kind. that's bit unlucky
04:33 PM ville: ok 5th cable the charm. things like this really make you want to kill people who've allowed that manufacturers can make cables with out all pinds connected
07:49 PM qu1j0t3: rue_mohr: yeah it just cannot work afaict without a good 2+ volt headroom
07:49 PM qu1j0t3: rue_mohr: back to analog switches...
07:51 PM rue_mohr: I could show you how to make a booster
07:51 PM qu1j0t3: oh?
07:51 PM rue_mohr: somewhere I have a supply that makes +7, -5V for analog circuits from 5V
07:51 PM qu1j0t3: oh.
07:51 PM qu1j0t3: nah
07:51 PM qu1j0t3: thanks.
07:51 PM qu1j0t3: the analog switches are doing okay
07:52 PM qu1j0t3: i could do like +8v/-8v rails if i really wanted, but i just ordered some -5/+5 modules so i'll cut corners on this one
07:53 PM qu1j0t3: (they were CAD $5 each)
09:15 PM qu1j0t3: rue_mohr: why are these things so damn fragile with their CURRENT LIMITS
09:15 PM qu1j0t3: rue_mohr: some of them 10mA :|
10:03 PM rue_mohr: yup
10:03 PM rue_mohr: tell me when your ready to Rue it
10:06 PM rue_mohr: WAIT
10:06 PM rue_mohr: you dont need to base64 an SVG, its already freaking text
10:11 PM qu1j0t3: ready to rue the day
10:12 PM qu1j0t3: rue_mohr: well, utf8 text, if i'm not mistaken. (based on xml?)
10:12 PM qu1j0t3: rue_mohr: so ... strictly speaking ... you would if you don't have an 8 bit clean channel
10:13 PM qu1j0t3: rue_mohr: one thing i have considered is to limit the signal range, but i did try this once and not sure it's a sensible thing to do just so i can use a mosfet to reset lol
10:16 PM rue_mohr: bipolars work really well, which I didn't expect
10:26 PM * qu1j0t3 nods