#robotics Logs

Oct 12 2019

09:08 AM robotustra: morning
10:33 AM rue_bed: need to gradually migrate to the shop where its warm
10:34 AM rue_bed: restarting work on my filter profiler
10:35 AM rue_bed: gonna change the target a bit too
10:36 AM rue_bed: as well as the output amplitude, I want to know what the voltage peaks are so I can know what bias the circuit has
10:38 AM robotustra: are you talking about your power supply?
10:39 AM robotustra: do you have snow?
11:48 AM rue_mohr: I dont have snow
11:48 AM rue_mohr: its actually become so warm up here that 2 years ago, everyones igloo melted away
11:48 AM rue_mohr: its caused quite the homeless problem
11:49 AM rue_mohr: but I'm making a machine for doing sweeps on filters
11:49 AM rue_mohr: output an amplitude/phase chart for the freq sweep
11:50 AM rue_mohr: aside from amplitude tho, I want to know the voltage of the high and low peaks
11:50 AM rue_mohr: becasue then I can sweep things that have diodes and know how digital chips will handle the signal
11:51 AM rue_mohr: as I' doing mroe and more hybrid digital/analog stuff latley
11:51 AM rue_mohr: it can go down to 1Hz, which I'm hoping to use for sweeping servos
11:52 AM rue_mohr: I'd love to know where the -3db point of a hobby servo is
09:55 PM Jak_o_Shadows: I could reverse engineer this part
09:55 PM Jak_o_Shadows: It's a LED display driver that somehow uses a multi-channel darlington array to drive a 2 digit LED dispaly
09:55 PM Jak_o_Shadows: or I could just make a part that fits int he same mounting holes
10:13 PM rue_mohr: what is it?
10:21 PM Jak_o_Shadows: I'm reusing an old (1993ish) computer case - it's a little 2 digit 7 seg display that used to show codes when the computer started up
10:23 PM chisight: wow, i thought my case was absurdly old being from the late 90s.
10:24 PM Jak_o_Shadows: well, this one has been sitting empty for nearly 2 decades
10:24 PM Jak_o_Shadows: well, nmot empty, unused
10:24 PM Jak_o_Shadows: but it amuses me to put new stuff into it
10:25 PM rue_mohr: port 80
10:25 PM rue_mohr: 0x80
10:25 PM Jak_o_Shadows: ?
10:25 PM rue_mohr: the bios status port is port 80
10:25 PM chisight: this one has been used pretty much continuously since it was new.
10:25 PM rue_mohr: try writing a program to just write to port 0x80
10:25 PM rue_mohr: er,
10:26 PM rue_mohr: well, if it wasn't part of the motherbaord :)
10:26 PM Jak_o_Shadows: yeah.
10:26 PM Jak_o_Shadows: apparently it used to be more of a thing - new motherboards just have the display onboard
10:26 PM rue_mohr: usually there was a 2 digit ont eh front of the machine to tell you what the speed was when it was in/out of turbo
10:26 PM Jak_o_Shadows: yes
10:26 PM Jak_o_Shadows: that is what this display was
10:26 PM rue_mohr: oh, then its set to display one of two numbers depending on the jumpers
10:27 PM rue_mohr: mm
10:27 PM Jak_o_Shadows: ahhhh
10:27 PM Jak_o_Shadows: yeah, ok.
10:27 PM Jak_o_Shadows: (there's a lot of jumpers)
10:27 PM rue_mohr: your making me feel old and I dont like it
10:27 PM rue_mohr: :D
10:27 PM Jak_o_Shadows: In that case reusing it probably wont' work - so I'll just make a munt-compatible copy
10:27 PM Jak_o_Shadows: ahah
10:27 PM Jak_o_Shadows: 'twas my first computer
10:28 PM rue_mohr: I'm reading a book trying to understand 1977 speech recognition tech
10:29 PM rue_mohr: several forms of making a spectral map and trying to compare it against reference maps