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by cpunk
Mon Aug 19, 2019 6:53 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 Ethernet Problem
Replies: 15
Views: 4398

Re: Raspberry Pi 4 Ethernet Problem

Update: I put a TP-Link wireless router downstream of it ( with routing functionality disabled in the TP-Link, so essentially my TP-Link is a switch with antennas or an access point ). Raspberries started working fine, even ping -f loses no packets. Seems to be a compatibility issue with these Cisco...
by cpunk
Mon Aug 19, 2019 12:55 pm
Forum: Troubleshooting
Topic: Raspberry Pi 4 Ethernet Problem
Replies: 15
Views: 4398

Re: Raspberry Pi 4 Ethernet Problem

Wow, this is exactly like my situation (thread over here ). I have an "EPC3940ADL EuroDocsis 3.0 2-PORT Voice Gateway" acting as my router, and I experienced packet losses of approximately 40%. Static IP didn't help. Disabling IPv6 didn't help. I presume the ethernet interfaces try to reach gigabit ...
by cpunk
Sat Aug 17, 2019 7:05 am
Forum: Troubleshooting
Topic: Big packet loss (up to 40%) after switching to Pi4
Replies: 3
Views: 638

Re: Big packet loss (up to 40%) after switching to Pi4

Until now, I have found no cure for this.

I switched over to WiFi however and left the Ethernet cables unconnected. Now, packet loss is 0%, but it's WiFi... it's not a long term solution for me. Will try to find a known-good gigabit switch to test with.
by cpunk
Fri Aug 16, 2019 11:25 pm
Forum: Troubleshooting
Topic: Big packet loss (up to 40%) after switching to Pi4
Replies: 3
Views: 638

Re: Big packet loss (up to 40%) after switching to Pi4

P.S. I also get big packet loss when I bring up a WiFi interface on a Pi and then try to ping it from my laptop on the same LAN. Pinging the router has 0% packet loss, pinging the Pi has 40%.

Ping times are around 2 ms in both cases.
by cpunk
Fri Aug 16, 2019 11:09 pm
Forum: Troubleshooting
Topic: Big packet loss (up to 40%) after switching to Pi4
Replies: 3
Views: 638

Big packet loss (up to 40%) after switching to Pi4

So I had 3 separate Pi3 computers on a LAN made of Cat5 Ethernet cables and a home router. One was a WWW server, another an API server, third one a DB server. I upgraded them to Pi4 and now I observe great packet loss, extending up to 40% of pings. All three exhibit this effect. SSH barely works but...
by cpunk
Fri Jun 01, 2018 10:16 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: XPT2046 Touch Screen instructions for Raspbery Pi 3
Replies: 51
Views: 150307

Re: XPT2046 Touch Screen instructions for Raspbery Pi 3

Thank you, everyone who wrote tips before. :) They were helpful. I recently purchased one of the 10.1 inch 1024x600 pixel resistive touch screen displays from Waveshare. My recipe for making it work was the following: -------------------- add to /boot/config.txt-------------------- # Enable XPT2046 ...
by cpunk
Tue Feb 06, 2018 10:37 pm
Forum: General discussion
Topic: TFT LCD 3.5" OSOYOO
Replies: 4
Views: 7212

Re: TFT LCD 3.5" OSOYOO

So I bought one for testing. They don't provide a driver. Instead they write: > "We do NOT support screen driver to be installed on existing OS on your Pi." I wonder how clueless can a manufacturer be? For what it's worth, the kernel or disk image they supply might contain dragons and elves, spyware...
by cpunk
Tue Dec 19, 2017 6:06 pm
Forum: Camera board
Topic: Non-blocking streaming and saving to a file (not a duplicate)
Replies: 2
Views: 928

Re: Non-blocking streaming and saving to a file (not a duplicate)

If nothing else worked, maybe you could: - tell netcat to use UDP transfer instead of TCP? - use socat instead of netcat? - modify "raspivid" to have dual outputs, one being "udp://" (it already supports that) and the other being a file? - or alternatively, write a "tee" like program yourself, conta...
by cpunk
Mon Dec 18, 2017 6:57 pm
Forum: Camera board
Topic: Howto capture 360fps (640x240) videos with Raspberry v1 camera (665fps for 640x128 !)
Replies: 7
Views: 4360

Re: Howto capture 360fps (640x240) videos with Raspberry v1 camera (665fps for 640x128 !)

Thank you for publishing such interesting results. :) My line following drone failed in competition, partly due to last-minute reconfiguration issues and partly because of time lost due to repairs after a mid-air collision with another team's drone (happy-go-lucky judges allowed two teams on the fie...
by cpunk
Fri Dec 01, 2017 1:43 pm
Forum: Camera board
Topic: How to sense gestures like right, left, front, back by using pi camera.
Replies: 3
Views: 815

Re: How to sense gestures like right, left, front, back by using pi camera.

To get gesture information, you might ask the "raspivid" command to output motion vectors from the video encoding process (there are other possibilities too). If you pick that route, you can do that with the -x command line option. The output will be one motion vector per each 16 x 16 pixel macroblo...
by cpunk
Tue Nov 14, 2017 12:20 am
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

P.S. For entertainment only... a test run that recognizes distinct areas and color-codes them. :) No longer a bug report... just getting close to something functional. :)
by cpunk
Mon Nov 13, 2017 11:16 pm
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

I can no longer recreate the bug when I work with the methods you recommended. :) But, I can show the advantages of manually adjusted settings over automatic settings, though. :) Here are 3 videos: - tiny video... - the yellow bar is an artifact from a different task entirely, plz ignore... - the bl...
by cpunk
Mon Nov 13, 2017 2:54 pm
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

Thanks for the really useful critique and explanation. :) I knew I had *some* contradictory arguments in that command line, but I didn't know I had so _many_. :) I'll try to narrow them down to the bare minimum needed, and see if I still encounter oddities or if they disappear - and I'll make use of...
by cpunk
Mon Nov 13, 2017 10:13 am
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

It's getting more and more complicated. :D I hereby (almost) promise to figure it out and make sense of it later, after the contest (on Nov 25). I was thinking that all was fine. Then I noticed instabilty in the robot's vision. I started investigating the fishy frames. I understood that either their...
by cpunk
Sun Nov 12, 2017 10:58 am
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

Sadly, for the time being, the bug defeated me. Since I'm preparing a robot for competition, I had to go around it - and my video pipeline script has transformed too, it now reads as below, and the problem doesn't happen: raspivid -sh 0 -sa -100 -br 70 -co 10 -fl -n -t 0 \ -w $1 -h $2 -b 400000 -fps...
by cpunk
Sat Nov 11, 2017 7:01 pm
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

Update: After upgrading all components and rewriting my homebrew "raspivid" command to totally exclude status messages polluting the "stderr" stream when it's being used for motion vectors, I was able to collect sample video. :) The better screenshot is from the TCP stream, the totally useless one f...
by cpunk
Sat Nov 11, 2017 5:17 pm
Forum: General discussion
Topic: How hard would it be to do something like this...
Replies: 1
Views: 383

Re: How hard would it be to do something like this...

It should be possible with reasonable amounts of coding. The basic problem seems to be "how to obtain a video feed as input, decode it to a form we can modifiy (such as RGB) and then draw "sprites" on top of the feed, and display it in a smooth enough manner?". I've personally done it many times in ...
by cpunk
Sat Nov 11, 2017 3:05 pm
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

Additional notes: - passing all ("-ex off", "-awb off" and AWB gains) --> somehow visibly altered motion vectors, tiny unreadable video file - omitting "-ex off", omitting "-awb off" and passing AWB gains --> correct behaviour - omitting "-ex off", passing "-awb off", and omitting AWB gains --> no m...
by cpunk
Sat Nov 11, 2017 2:36 pm
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

Re: "Raspivid" -o option behaving strange, affecting -x output

My first observation would be that I'm a bit silly. I'm passing the -f or "fullscreen" argument to a command that has no screen to draw on, and the -l or "listen" argument to a command that is outputting to a file... ...but removing those bits of my sillyness doesn't make the problem disappear... in...
by cpunk
Sat Nov 11, 2017 2:13 pm
Forum: Camera board
Topic: "Raspivid" -o option behaving strange, affecting -x output
Replies: 9
Views: 1547

"Raspivid" -o option behaving strange, affecting -x output

I will make my best attempt to solve this problem myself, since it would likely take others a long while to even recreate the conditions exactly... but since it is such an interesting problem for me, I want to also document what I saw, hence I'm opening this thread here. :) I'm working with my home-...
by cpunk
Sat Nov 11, 2017 11:41 am
Forum: High Altitude Balloon
Topic: Balloon on a budget
Replies: 3
Views: 11619

Re: Balloon on a budget

I got them. :) And thanks to a recommendation from a friend, I also found an ideal solution for the filling valve. :) I used part of a long-necked plastic energy drink bottle, neutral construction silicone and electrical tape. Recipe: - cut off bottle neck - make it smooth, wrap cutting line in two ...
by cpunk
Wed Nov 08, 2017 4:09 pm
Forum: Java
Topic: Problem with gnu.io.RXTXCommDriver
Replies: 3
Views: 4976

Re: Problem with gnu.io.RXTXCommDriver

So I tested them, with as much time I had. I needed to get a Scanse Sweep rotating lidar working, and get it working soon... ...I wrote the initial code for jSerialComm and it worked on my laptop. On a Pi 0W unit, it mysteriously did nothing, with no error messages whatsoever. The port opened, but n...
by cpunk
Fri Nov 03, 2017 8:00 pm
Forum: High Altitude Balloon
Topic: Balloon on a budget
Replies: 3
Views: 11619

Re: Balloon on a budget

An idea about where to get cheap balloons: "BWS Zeppelinballon" or "GL-500"... apparently made of latex and very big. No idea about lift, still waiting for my first parcel. But quite cheap.

https://www.ebay.de/itm/BWS-Zeppelinbal ... 2486493655
by cpunk
Thu Nov 02, 2017 11:12 pm
Forum: Camera board
Topic: How to bypass the crypto chip in my raspberry pi camera (v2) [you can't!]
Replies: 37
Views: 11328

Re: How to bypass the crypto chip in my raspberry pi camera (v2)

Thanks for the explanations. :) I was not intending to ask, but it was enlightening anyway. And sure enough, I understand that having one's camera design copied and then distributed at a significantly undercut price (because there were no design expenses) wouldn't be fair. I personally like designs ...
by cpunk
Thu Nov 02, 2017 10:58 pm
Forum: Java
Topic: Problem with gnu.io.RXTXCommDriver
Replies: 3
Views: 4976

Re: Problem with gnu.io.RXTXCommDriver

Another RxTx user here, and thanks for the tip. Will try the alternative in my next project. :)

My personal experience is that it works better with OpenJDK JVM, as opposed the Oracle JVM. Probably another of those library loading issues. Most likely quite solvable, but needs lots of trying.

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