These are chat archives for machinekit/machinekit

24th
Jul 2016
Michael Haberler
@mhaberler
Jul 24 2016 11:04
3-phase pwm (top 6 sigs) + 1 PWM (bottom): http://static.mah.priv.at/public/3pwm+pwm.png
I think I have it all figgad!
oops wrong channel
anyway
zhivko
@zhivko
Jul 24 2016 11:05
Nice pic anyway ;)
Michael Haberler
@mhaberler
Jul 24 2016 11:05
socfpga hostmot2 generating 3-phase inverter signal, low and high side
zhivko
@zhivko
Jul 24 2016 11:06
so you are making progress with fpga board?
is it cetus ?
or what's called ?
Michael Haberler
@mhaberler
Jul 24 2016 11:07
cetus is a UI
this is a FPGA image I created, and slowly understand how it is configured
this is a logic analyzer screenshot
zhivko
@zhivko
Jul 24 2016 11:08
ah - xilinx ?
Michael Haberler
@mhaberler
Jul 24 2016 11:08
no altera
zhivko
@zhivko
Jul 24 2016 11:08
yes . but board is ---... ah yes
Michael Haberler
@mhaberler
Jul 24 2016 11:08
but zynq works as well, just no sd image yet
zhivko
@zhivko
Jul 24 2016 11:08
very nice...
For my needs now BBB is enough it seems...
Michael Haberler
@mhaberler
Jul 24 2016 11:09
I scoped stepgens at 3.7Mhz and the encoders work up to 700kHz input
zhivko
@zhivko
Jul 24 2016 11:09
who would need such big precision ?
Have you saw onion liux board lin I sent ?
Michael Haberler
@mhaberler
Jul 24 2016 11:10
I have a spindle with a 3600ppr encoder - that generates an A/B signal at 250kHz at full speed
zhivko
@zhivko
Jul 24 2016 11:10
What do you think ? This is a linux board for 5$, wifi integrated
Michael Haberler
@mhaberler
Jul 24 2016 11:10
yes I saw it, but I would not know what to do with it?
zhivko
@zhivko
Jul 24 2016 11:10
I could us it instead esp8266, that I thought to be used as linear encoder
and than really use c++ ful blown stack to program haltalk client
you remember a talk we had back ago ?
Michael Haberler
@mhaberler
Jul 24 2016 11:11
you cannot possibly use a userland comp plus wifi as parts of a servo loop, this is orders of magnitude too slow
zhivko
@zhivko
Jul 24 2016 11:12
ah ok - but it seems nice homework ;)
Michael Haberler
@mhaberler
Jul 24 2016 11:12
for working out the stack that is fine
zhivko
@zhivko
Jul 24 2016 11:12
But really - than maybe just use another pin from BBB, to use it for encoder...
for closed loop
Michael Haberler
@mhaberler
Jul 24 2016 11:13
that is the problem which is solved with the fpga platforms - GPIO count not an issue, and number of on-board encoders or whatever functional units not an issue
zhivko
@zhivko
Jul 24 2016 11:13
I am now thinking about turning spindle on and off - could it be done with remote comp ?
Or should I just use mdi command M3 and M5 ?
Michael Haberler
@mhaberler
Jul 24 2016 11:14
well the result of m3 and m5 eventually influences a HAL pin
but if you have the cnc stack running you want the mX commands, yes
zhivko
@zhivko
Jul 24 2016 11:14
yes but I was thinking - remote component would have lovest latency
Michael Haberler
@mhaberler
Jul 24 2016 11:14
for spindle ops????
zhivko
@zhivko
Jul 24 2016 11:15
:( oops - I will stay wight gcode and mdi :)
Michael Haberler
@mhaberler
Jul 24 2016 11:15
also it's nonsense to intervene at the hal level if the whole thing is driven from the cnc stack above
very good idea
zhivko
@zhivko
Jul 24 2016 11:16
how would xilinx board look like? is there some hat to make it 5V tolerant ?
Michael Haberler
@mhaberler
Jul 24 2016 11:16
not that I know of
I use the myir z-turn
zhivko
@zhivko
Jul 24 2016 11:17
or how you imagine one should use it? should then some extra HATS be made? for such fpga to be used in diy projects ?
Michael Haberler
@mhaberler
Jul 24 2016 11:17
you can use the gpio pins directly too but they are unbuffered and no isolation
Charles card gives buffering
zhivko
@zhivko
Jul 24 2016 11:20
OK... its good to know that you experts are byting this hard stuff... but for me ... i have a lot of work with connecting plasma.... now...
i have made video of machine in action... if you wanna check: https://youtu.be/Aoq8KcUa9Lw?t=8
prototype still..
Michael Haberler
@mhaberler
Jul 24 2016 11:24
cool!
lots of mechanics . Do you work at that company?
zhivko
@zhivko
Jul 24 2016 11:29
Its my fathers company, I work for telco company otherwise ... this is also the reason why there is slow progress...
but - persistence is also important... :)
Michael Haberler
@mhaberler
Jul 24 2016 11:31
telecom SI?
zhivko
@zhivko
Jul 24 2016 11:31
yes
Telekom