#garfield Logs

Mar 30 2014

16:06 rue_more http://paste.debian.net/90628/
16:07 TELunus what's that?
16:07 rue_more short form
16:07 rue_more http://paste.debian.net/90632/
16:07 rue_more 60-60+60
16:07 rue_more so 60+60 is 120, makes 60-120 = -60
16:08 rue_more however 60-60=0
16:08 rue_more 0+60 = 60
16:09 rue_more so whats the answer...
19:28 TELunus For sums there isn't priority like that. So It's the sum of all terms, where each term added preceded by a minus sign instead of a plus sign is consedered the negative of the term you are adding. So 60-+0
19:28 TELunus I mean 60-60+60 =
19:28 TELunus 60
19:29 rue_more so your saying (+60) + (-60) + (+60)
19:30 rue_more TELunus, done charlieplexing yet?
19:31 TELunus What's charlieplexing?
19:31 rue_more OOoooo
19:31 rue_more how do you operate 6 leds with 3 3-state lines?
19:31 rue_more how about 12 leds with 4 lines?
19:33 TELunus Any three objects have six total unordered pairs.
19:34 TELunus So first you wire the LEDs each to a pair of wires.
19:34 rue_more and their diodes
19:34 rue_more so they are polarity sensitiv
19:34 rue_more with 2 wires, you can operate 2 leds
19:34 rue_more no grounds
19:35 TELunus Oh, I wasn't thinking.
19:35 rue_more if you add a 3rd line
19:35 TELunus You have 3 unordered pairs, 6 ordered pairs.
19:35 rue_more then, you can put leds between all 3 lines
19:35 rue_more but each one can be back to back leds
19:35 TELunus But then you'll need to do pulse width if you want multiple on at a time.
19:35 rue_more 6 leds total
19:36 rue_more you would need to scan them, yes, or not
19:36 rue_more depends, with 3 lines, 6 diodes, you can have some combinations of 2 on at once
19:37 TELunus Ya. But there will be at least 3 mutually exclusive pairs, unless you pluse.
19:37 TELunus Of course if you pulse you get a lower average voltage than the amplitude of your square wave.
19:38 rue_more one led on | two leds on
19:38 rue_more H H L -> 0 0 1 0 0 1
19:38 rue_more H Z L -> 0 0 1 0 0 0
19:38 rue_more H L H -> 1 0 0 0 1 0
19:38 rue_more H L Z -> 1 0 0 0 0 0
19:38 rue_more H L L -> 1 0 1 0 0 0
19:38 rue_more Z H L -> 0 0 0 0 0 1
19:38 rue_more Z L H -> 0 0 0 0 1 0
19:38 rue_more L H H -> 0 1 0 1 0 0
19:38 rue_more L H Z -> 0 1 0 0 0 0
19:38 rue_more L H L -> 0 1 0 0 0 1
19:38 rue_more L Z H -> 0 0 0 1 0 0
19:38 rue_more L L H -> 0 0 0 1 1 0
22:14 rue_more https://www.youtube.com/watch?v=uPml5xC_I00