#garfield Logs

Nov 18 2021

12:04 AM rue_mohr: I forgot to put supper on
10:47 AM aandrew: WormFood: there are lots of nRF24L01+ clones, they all work the same: spi on the control side, they do GMSK or GFSK and have a number of address filters and if configured, will auto-ack and auto-retransmit if they don't get an ACK
10:47 AM aandrew: done a LOT of work with those devices, the same core is in the nRF51 and nRF52 devices, although the PLL in the nRF52 is MUCH faster than the nRF51/24
10:58 AM WormFood: aandrew, how reliable and easy to work with are they?
11:04 AM WormFood: Yesterday, I'm sitting at my computer, and hear this boom, like a small bomb. I look out the window, just in time to see a squirrel fall from the power pole, and a few seconds later, I see the fuse swing down on the "pole pig" (transformer). The power company had the power back on in about 15 minutes. I was really impressed with their speed.
11:04 AM WormFood: The guy said it was his 2nd squirrel of the day, and it was only 10 am.
11:49 AM aandrew: WormFood: they're quite reliable and trivial to work with. lots of libs for them already
04:23 PM Tom_L: https://moveit.ros.org/
07:27 PM rue_mohr: heh
07:30 PM rue_mohr: aandrew, ISBN-10 ‏ : ‎ 3899291573 ISBN-13 ‏ : ‎ 978-3899291575 your the magic pdf person, what can you do?
07:33 PM rue_mohr: spice, so it might not be usefull to me anyhow
07:33 PM rue_mohr: I dispise simulators
07:51 PM Tom_L: did a tiny bit of tuning on my config
07:52 PM Tom_L: all those zeros on the pendant scale? (you mentioned that)
07:52 PM Tom_L: i did remove some but if i get it too coarse, it doesn't jog properly even though it's going the correct distance
07:57 PM rue_mohr: it should balance out with another number thats huge
07:58 PM Tom_itx: setp mux4.0.in0 .0000025
07:58 PM Tom_itx: setp mux4.0.in1 .000025
07:58 PM Tom_itx: setp mux4.0.in2 .00025
07:58 PM Tom_itx: now
07:59 PM Tom_itx: removed 2 zeros
07:59 PM Tom_itx: then on the lowpass i removed 2
07:59 PM Tom_itx: setp ilowpass.0.scale 10
07:59 PM Tom_itx: setp ilowpass.1.scale 100
07:59 PM Tom_L: instead of 1000 and 10000
08:00 PM Tom_L: any less and the steppers get choppy
08:26 PM rue_mohr: oops nodded off, today might not be the day
08:26 PM rue_mohr: forgot my 2:00 B complex
10:13 PM rue_bed2: and I just woke up
10:13 PM rue_bed2: gee that sucks
10:13 PM rue_bed2: I wonder if I can play with what I wanted to yet
10:13 PM rue_bed2: I need to work out supper
10:14 PM Tom_L: yeah you forgot it last night
10:15 PM rue_bed2: I had it late, but I was ok
10:16 PM rue_bed2: has to be ~2:00
10:29 PM aandrew: rue_mohr: I can't get that one, that's actually in my amazon wish list. like $300
10:29 PM aandrew: rue_mohr: I do have McLyman's book on inductor core selection
10:32 PM aandrew: er no, $100 not $300, maybe that's a different one
10:32 PM aandrew: I know Ott's book is $200
10:33 PM aandrew: maybe both sets was $300 is what I'm remembering
10:38 PM aandrew: https://ibb.co/PGLXjWZ that wasn't too bad
10:38 PM aandrew: is there something like a 125 that doesn't do hiz, just low if not enabled?
10:38 PM aandrew: and gate with one inverted input would be fine but that's imaginary
10:40 PM rue_mohr: is ti a good book tho,...
10:43 PM rue_mohr: .. what the heck is that aandrew ?
10:43 PM rue_mohr: it looks like half a pwm steering system
10:43 PM aandrew: I need to route a PWM to one of four destinations (and measure the current of whatever it is I'm PWMing
10:43 PM aandrew: yep
10:44 PM rue_mohr: but
10:44 PM rue_mohr: TLC5940
10:44 PM aandrew: need to measure a range of about 20mA - 2000mA on the analog feedback
10:45 PM rue_mohr: hmm
10:45 PM rue_mohr: how about a CT :)
10:45 PM rue_mohr: I'm gonna go put 1 turn around a 100mH axial and see
10:46 PM aandrew: TLC5940 is unobtanium and besides, doesn't handle nearly the current I need
10:46 PM rue_mohr: but its multichannel
10:46 PM aandrew: also 12 too man channels :)
10:46 PM rue_mohr: heh
10:47 PM aandrew: I only have 4, and one of them I need to use a boost regulator for since it's ~20V with 6 LEDs in series
10:47 PM rue_mohr: what if, instead of measuring the current, you set it
10:47 PM rue_mohr: via a flyback circuit,
10:47 PM aandrew: I thought of that too, I don't particularly like what I'm doing here but it's oky for a v1
10:48 PM rue_mohr: thats output current it determined by the pulse time
10:48 PM rue_mohr: I'm nose deep in inductors :)
10:48 PM aandrew: I can tell
10:48 PM aandrew: when all you have is a hammer, everything looks like a thumb. :-)
10:49 PM rue_mohr: but inductors are complex enough to do anyting
10:49 PM rue_mohr: even logic..
10:49 PM aandrew: you're gonna "yup" an inductor next aren't you
10:49 PM rue_mohr: been there, done that
10:49 PM rue_mohr: or you mean, make IT the new yup
10:56 PM rue_mohr: what is the ratio Vin/Vout?
10:59 PM aandrew: hm? for what, the boost regulator or my pwm range?
11:00 PM rue_mohr: voltages
11:00 PM rue_mohr: whats going in and what will the leds eat?
11:02 PM aandrew: well I noted on the schematic so I wouldn't forget. Flourescence is just one LED, ~3.2V up to 2A
11:03 PM aandrew: brightfield is one LED as well, similar (3.4V, 1.5A)
11:03 PM aandrew: sidescatter is 3 LEDs in series (hence the 12V supply instead of 5V), they're dropping approx 3 * 2.3V at 800mA
11:04 PM aandrew: and the last one is a completely separate circuit so it doesn't matter, it's 6x red LEDs, so 6 * 3.2V (yep it's a weird red led) at around 400mA, which I don't believe because those LEDs are only rated 20mA and they're currently in parallel
11:08 PM rue_mohr: so low voltage
11:09 PM aandrew: yes, definitely
11:15 PM rue_mohr: hmm
11:15 PM rue_mohr: 3.3V or 5V system?
11:16 PM aandrew: both
11:16 PM aandrew: but the logic driving the FETs is 3.3V
11:16 PM rue_mohr: the supply tho
11:16 PM aandrew: for the LEDs?
11:16 PM rue_mohr: system
11:17 PM aandrew: the two single ones are 5V, the 3 in series is 12
11:17 PM aandrew: I have 3.3, 5, 12 and 48 available, although 48 is less available
11:19 PM rue_mohr: whats the supply?
11:19 PM rue_mohr: the primary
11:22 PM aandrew: 48, but there's already the other voltages provided to this board by the power supply
11:29 PM rue_mohr: k
11:29 PM rue_mohr: definitly would want to work with something lower than that
11:29 PM rue_mohr: well
11:29 PM rue_mohr: hmm yea
11:30 PM rue_mohr: even for ~1mH the charge time would be pretty small