#garfield Logs

Sep 28 2021

#garfield Calendar

09:19 AM rue_mohr: morning everyone
09:27 AM Tom_L: still alive
09:27 AM rue_mohr: thumbs up
09:46 AM rue_mohr: ok, rue to work
07:09 PM rue_mohr: ok, back from work
07:54 PM polprog: how was it/
07:54 PM polprog: ?
07:54 PM rue_mohr: meh
07:54 PM rue_mohr: we were efficient
07:54 PM polprog: its 3 am cause im helping some kid make a z80 computer run
07:54 PM polprog: i mean
07:54 PM rue_mohr: heh
07:54 PM polprog: its not 3am because of that
07:55 PM polprog: its because im not sleeping
07:55 PM polprog: im figuring out my IR datalink project
07:55 PM polprog: found out the hard way i need CRCs in the packets
07:56 PM polprog: so ill be doing that tomorrow...
07:56 PM polprog: ... if i wake up
07:56 PM rue_mohr: did you look up irda?
07:56 PM polprog: to some small extent
07:56 PM rue_mohr: how about TOSlink?
07:56 PM polprog: i have my own small physical layer on the 38kHz modulation
07:56 PM rue_mohr: mh
07:56 PM polprog: it's not over cables
07:56 PM rue_mohr: mhm
07:57 PM rue_mohr: toslink is optical
07:59 PM polprog: yeah i meant fiberoptic cables
07:59 PM polprog: although it would be cooler to have visible light comms
07:59 PM polprog: more tangible
07:59 PM rue_mohr: it might have some good integrity stuff
07:59 PM polprog: this will be an educational kit in the end
07:59 PM polprog: no, i want it wireless
07:59 PM rue_mohr: yes
08:00 PM polprog: gotta use the integrated IR receivers
08:00 PM rue_mohr: but it might have error stuff
08:00 PM polprog: thats why i need the CRCs
08:00 PM polprog: errors seem to happen only when there is a collision
08:01 PM polprog: while its easy to detect a collision while TXing, its harder to do that while RXing
08:01 PM polprog: you get a frame error
08:01 PM polprog: so I have to check the header and/or packet CRCs
08:01 PM polprog: and just drop bad packets
08:01 PM rue_mohr: no "what" like tcp?
08:02 PM polprog: not on this protocol level
08:02 PM polprog: this is packet level
08:02 PM polprog: that will be later
08:02 PM rue_mohr: hmm
08:02 PM rue_mohr: just make it slow ethernet :)
08:03 PM polprog: now i want an array of bytes come from A to B (possibly via C, D and E) in unchanged form
08:03 PM polprog: :)
08:03 PM polprog: 1BASE-T
08:03 PM polprog: or not -T
08:03 PM polprog: -FX? shoot, i dont remember the led wavelength
08:04 PM polprog: but I could easily swap the hardware leds and receivers for integrated fibreoptic receivers, i have 4 waiting
08:04 PM rue_mohr: :)
08:04 PM polprog: wanted to make a 100MBaud trx arduino shield
08:04 PM polprog: :D
08:04 PM rue_mohr: heh
08:04 PM rue_mohr: you could restrict the packet size and make it a link level hardware device
08:05 PM polprog: make what?
08:05 PM rue_mohr: the ir link
08:06 PM polprog: yeah, i could
08:08 PM polprog: would be nice to roll my own fiberoptic link
08:08 PM polprog: im pretty proud of this, i started with a softuart implementation onthat
08:08 PM rue_mohr: :)
08:09 PM polprog: that softuart was modified to drive a led at 38kHz (FSM with extra steps stepped by timer ISR)
08:09 PM rue_mohr: I need to get hooked on a project
08:09 PM rue_mohr: I'm drifting
08:09 PM rue_mohr: its annoying
08:09 PM polprog: planning to make money on it in undefined future helps
08:09 PM polprog: but i have like 2 or 3 other projects on
08:09 PM polprog: at the same time :V
08:09 PM rue_mohr: hmm
08:10 PM polprog: when I get it all working i wanna make several boards with different stuff and make it into an educational kit
08:15 PM rue_mohr: http://www.z80.info/z80undoc.htm
08:55 PM aandrew: hm, I think this is the first USB key I've destroyed. it was returning bad sectors and making my firewall unhappy. new usb key, happy firewall again
09:00 PM rue_mohr: hmh
09:00 PM rue_mohr: mhm
09:00 PM rue_mohr: I cant type anymore
09:01 PM rue_mohr: and I need to get obsessed on a project
10:41 PM aandrew: rue_mohr: ... you stick cat whiskers in random holes in your walls?
10:41 PM rue_mohr: pff no
10:42 PM rue_mohr: I start from one hole and work my way out in a circular fassion
10:42 PM aandrew: the weird part wasn't the random vs methodical hole selection, my friend...
10:43 PM rue_mohr: well you cant just throw out a thing like that you know!
11:31 PM rue_shop3: 187kHz, 20%
11:58 PM rue_mohr: huh the math doesn't add up
11:59 PM rue_mohr: there is a power converter for led solar lights
11:59 PM rue_mohr: they have a table