#linuxcnc-devel Logs

Dec 15 2019

12:58 PM skunkworks: burklefoo: http://electronicsam.com/images/greenmachine/IMG_20191215_124239.jpg
01:15 PM burklefoo: Ahh you have the crimper for the AMP shells?
01:24 PM skunkworks: amp shells?
01:25 PM skunkworks: I have the dupont crimper.. I didn't redo all the splices - but the ones I didn't like...
01:25 PM skunkworks: that does the header connector
01:25 PM burklefoo: the .1" pitch individual wire socket shells
01:25 PM skunkworks: yes
01:25 PM skunkworks: it is pretty nice.
01:25 PM skunkworks: or seems to be
01:26 PM skunkworks: burklefoo: https://www.amazon.com/Crimping-Preciva-Ratcheting-Connectors-0-1-1mm%C2%B2/dp/B07R1H3Z8X/ref=sr_1_4?keywords=dupont+crimper&qid=1576437589&sr=8-4
01:27 PM skunkworks: I am going to have to get magnifiers one of these days.. Old person eyes
01:29 PM skunkworks: I found a zip drive cable that seems to be working with no noise..
01:29 PM burklefoo: Yeah I have some protos to do with .5mm pitch QFNs not sure I can set then down in the exact right place first time (too shakey)
01:29 PM skunkworks: the right lenght
01:30 PM skunkworks: I always shake.. people cringe when they see me soldering or doing fine work..
01:31 PM burklefoo: An issue with bare FPGA (or parport) inputs is that 1 usec (or even shorter) impulse noise will cause an input change (if sampled at the right time)
01:34 PM burklefoo: That crimper/part set looks nice (though I usually just use the IDC headers we have and split/splice the flat cable)
01:34 PM skunkworks: heh that is what I used to do... Hack stuff out of old computers and splice
01:34 PM skunkworks: http://electronicsam.com/images/greenmachine/IMG_20191215_131330.jpg
01:36 PM skunkworks: other than trying to make my own 25 pin ribbon cable... noise hasn't been an issue.
01:36 PM skunkworks: but time will tell
01:36 PM skunkworks: jepler: are you planning on making an image for rpi4?
01:36 PM burklefoo: You could try the inm (or maybe wait until its merged)
01:38 PM skunkworks: sure - that was the plan until I found the iomega cable :)
01:38 PM burklefoo: yeah easier to change cables
01:41 PM burklefoo: But a 200 usec or so digital filter is pretty immune to impulse noise (crosstalk or ground loop coupled impulse noise tends to be less than a couple usec in length)
02:46 PM jepler: skunkworks: that's something that peter's asked me to investigate, yeah. I haven't gotten far.