"Build It Yourself" Log

konokaiden

I went ahead and renamed it something that I would look for as a newcomer. I think it's less technical in wording, and therefore easier to understand/easier to find, for a broader audience. As for the wiki, I did just add one thing because Ive still only completed the physical electronics. I've been busy with school and with the holidays, so I haven't gotten to the wiring or software yet beyond what I've already done. I won't log that until I've done it from start to finish, that way people know that what I'm saying is actually how I did it so that it works in the end. That way they don't run into "I tried it this way and then it failed, so I had to do this other thing", because I tend to do walkthroughs piece by piece. So if there are any mistakes, I will follow that too by mistake because those weren't removed. So I want to make sure my thing works before saying "this is how you do it".

But yeah, I added my stuff to the wiki because that's all the current software/BOH/Gerbers for the 2.3 after I updated the manufacturer and parts, as well as added entries for the other locations on the circuit which actually aren't used. I want people to look at my stuff and have all the information, rather than having to also seek out logs and entire project histories to find out that "oh, TP5 is just a test point and nothing goes in that hole". So this log will be like "if you see pictures or videos, this is the section you need to read, and you'll do everything correctly if you follow this. Nothing goes unexplained or corrected later."

As far as what I need to move forward, I'm working through the wiring with my electrical engineer stepfather, so he can explain that all to me and help me with it. But the software still puzzles me. In order to get notochord working, do I need to do the SSH thing? That's what I'm looking at now in order to get things working, but I'm not sure how to see that Notochord is running, or how to edit it and rename the bones, which I need to do for my applications. Even if you can't explain that process here, I'd appreciate if you link the article on the wiki or other location where it is discussed.

konokaiden

I would like to suggest making https://wiki.chordata.cc/wiki/User_Manual/1._Chordata_parts/1.1._Microcomputer
significantly more prominant. There is one line in this one section which tells you the user name and password for notochord, and the entire rest of the wiki gives the wrong idea about having access to some command line or the Chordata-net login combo. I've spent about a day and a half installing the raspberry pi OS, reflashing the notochord, etc because I had no idea how to get the Pi working and ready for me to use any commands.

I also have basically no idea how to use it as "plug and play", where you give it power and it sends signals to the computer about position and orientation. So if those sections could be made more prominent, that would be much appreciated... But I think "how to set up wifi" is prominent enough, I had no trouble figuring that part of the process up, and the SSH thing is another one I found easily enough, so it is fine. It's just the details about starting the system for the first time, as well as starting the recording, seem to be hard to find.

konokaiden

Also, a couple of important questions - when setting up the wifi, I did method 1, and checked it, but only got back the physical address for the ethernet (dc.sb.34.542.532 something like that) rather than the usual set of numbers (193.168.0.0). I then tried deleting the Chordata-net entry and just have my wifi in there, but that fried the thing, so I'm once again setting that card up from scratch.

I'm going to try using just method 2, but do you know if raspberry pi 4 has a slightly different procedure to find out your IP address?

konokaiden

Did some playing around in the shell, turns out ifconfig has a lot of subcommands. So I first had to correct the # in my password for the network, because the key for \ is the # in that. And if you want to type quotes, you need to hit @ instead of " because those two are swapped in the shell.

But anyway, after a bit of reading from the makers of Linux, via the shell and the "help" and "info ifconfig" commands, I discovered "ifconfig -a" which told me that I had three connections total. I had "eth0" which was my ethernet, I had "lo" which was my Wifi, and it had an IP address in the format I was looking for, and I had "wlan0" which is once again, my ethernet.

So if this is obvious to the team, it isn't mentioned at all in the wiki, but it seems like "ifconfig wlan0" will always return the ethernet connection even if you add your own wifi and even if you remove the default network, and you will never get the IP address. But there's another issue.

My "lo" connection was given the status "loopback", so I can imagine a universe in which wlan0 is the active network connection, and anything in loopback status is not set to wlan0. But there is no menu which allows me to set the active connection from ethernet to Wifi, so I don't know if the Wifi is working or not. Considering the fact that I tried to access the IP address that was given via PUTTy, and it wouldn't, I suppose that means "loopback = not working".

Any help that anyone can give would be nice. Or just information about all of this.

daylanKifky

Hi!
the loopback connection is a virtual connection which exists even if the physical ones are down. its IP will normally be 127.0.0.1 and it's used to reference the same machine where a communication was originated

The "eth0" should be your wired ethernet connection and the "wlan0" the WIFI one.
In order to enable or disable an interface you can use the commands ifup and ifdown.
For example to disable the WIFI you can go:

ifdown wlan0

After that the ifconfig status should be DISABLED for the wifi.

In order to assert a particular connection is working you can try pinging it from another computer like:

ping <ip_address>

if you get a response it means the connection is reachable from the outside

konokaiden But there is no menu which allows me to set the active connection from ethernet to Wifi,

There's no problem with having both connections active, you will get two different ip addresses and should be able to communicate with each one of them.

konokaiden I first had to correct the # in my password for the network, because the key for \ is the # in that. And if you want to type quotes, you need to hit @ instead of " because those two are swapped in the shell.

Is seems like your physical keyboard layout don't match the one set on the raspberry. By default it comes with a british english layout configured. You should be able to change with

sudo raspi-config

konokaiden

So, I need your help on this then. I have the correct password in the Raspberry Pi, here's the type of encryption my router is in (password is hidden, don't worry).

And yet it is on loopback, and on the right side of wlan0, it gives

wlan0 = bla bla (dc.a6.bla.bla.bla) Ethernet
etc
etc
etc

I can add a picture if it helps, but with it still being on loopback despite having the correct password, I don't really know what to do about this.

konokaiden

daylanKifky

from your screenshot it seems like the WIFI is not connected yet. You will se an inet field on the ifconfig result once you are connected.
The ether field is the device MAC address, a low level address you normally don't have to worry about, all that you need is the current IP address.

I see that you entered the WIFI password using the raspbian desktop interface. Do you get the "connected" status on the WIFI widget on the top-right corner of the screen?

konokaiden

Aha! It was the difference in an underscore and a dash in the ssid name. I can now use putty to enter the notochord.

konokaiden

Okay, now I'm having difficulty with getting the wiring...

I ordered RJ12 6p6c connectors. The first kind I got were accidentally asymmetric, which is not going to work, so I ordered a second set more carefully. Those came in, and still don't fit!

The jacks on my boards are these: https://www.digikey.com/en/products/detail/w%C3%BCrth-elektronik/615006141121/2627284
A representative at Wurth Electronic said that they are designed to fit RJ25, but everything I see says that RJ25 is the same as RJ12 (plus, even if it was different, it can't be bought as "RJ25"...)

So I need a ways to get wires that fit my connectors..... The ones I have seem like they will fit fine, but they just don't go in and make that normal secure snapping sound. So I'm not sure what's going on or how to get things straightened out...

daylanKifky

konokaiden
could you put a link to the RJ12 headers you bought?

konokaiden

Sure. The first ones I bought were like this, and the asymmetry was a problem:
https://www.showmecables.com/rj12-dec-modular-connector-6p6c-flat-cable-10-pack?gclid=CjwKCAiAgJWABhArEiwAmNVTB5h94ehb-2P8uW48seKwgkdJOfu4iBi0mYHzCo4MPCOXXuNp7HxqrBoCLRAQAvD_BwE

Then I ordered these, and it still didn't fit...
https://www.grainger.com/product/13U661?gclid=CjwKCAiAgJWABhArEiwAmNVTB9k08wPWEnQFB_h5ldtvTJU7dccs5Rx8i6bj015b7KarD_MAggewKRoCKdQQAvD_BwE&cm_mmc=PPC:+Google+PLA&ef_id=CjwKCAiAgJWABhArEiwAmNVTB9k08wPWEnQFB_h5ldtvTJU7dccs5Rx8i6bj015b7KarD_MAggewKRoCKdQQAvD_BwE:G:s&s_kwcid=AL!2966!3!281698275252!!!g!470952775171!&gucid=N:N:PS:Paid:GGL:CSM-2295:4P7A1P:20501231

and because of the limited image, it should be identical to this:
https://www.googleadservices.com/pagead/aclk?sa=L&ai=DChcSEwjQl4bD2qXuAhUzOLMAHb4nBXIYABAJGgJ5bQ&ohost=www.google.com&cid=CAESQeD2GI91JYkA5xEOqgDFcujQf77I0E8-2VQNxznbCablXRb8xaingP4DdnoSh_n0bbMfjvzcPRf2JI4fZY8RT63G&sig=AOD64_2nRGmy_YdbZyVY4qIrLYErTis4Mg&ctype=5&q=&ved=2ahUKEwibuf3C2qXuAhVJwlkKHQGcAK0Q9aACegQIDRBL&adurl=

The first one looks exactly like the one I bought, the second one is the exact entry that I bought, and the third one looks like the second one, except you get more angles to look at it from.

daylanKifky

konokaiden Then I ordered these, and it still didn't fit...

They look like the correct one, but that supplier is not providing a datasheet were to check the measurements.

Have you tried crimping them before trying to fit them in the connector? before crimping the contacts stick out of the plastic body, perhaps that's the problem.

Otherwise try getting the connectors from the same supplier you've got the jack. they put a link to the datasheet on each product page, double check the measurements there

konokaiden

I wondered about the contacts being the problem, so I'll crimp those that I have first and see if that works out. Otherwise, I'll look into getting some headers from Wurth.

konokaiden

Okay, once crimped, the wiring fits perfectly.
So here's where I am now:

Built the circuits: Check (need to fix a couple that had soldering issues)
Set up the notochord for SSH: Check
Wire a few Kceptors to the Hub: Check
Set up Blender app: Check

Next steps:
1) Print box for Kceptors and Hub (and Pi) to sit in.
2) Fix the 5 Kceptors that lost resistors due to bad soldering
3) Get Velcro to attach everything to body
4) Get battery pack for Pi
5) Spray the 3D printed boxes with Anti-static spray to reduce risk of electrical damage (already own spray)
6) Calibrate the Kceptors (?)
7) Use the system

My only question on Number 6, do each of them have to be calibrated with the cardboard box before using the system, and if so, how often is one calibration supposed to be good for?

daylanKifky

great!
I would suggest you to connect all the sensors and have the default_biped configuration working before doing the extra stuff like printing the boxes, attaching with velcro, etc. That way if you need to fix something in the hardware you won't need to undo those parts of the process.

The sensors should be calibrated only once, and they should last that way for a long time. Sometimes when mounting them on a box or support the physical properties of the sensor change and they should be calibrated again.
Keep in mind that the cardboard calibration box is just a helper to better guide you in the process of calibrating. You can eventually do the same procedure without it

konokaiden

Yeah, my actual order to things is to get the 5 sensors which lost a resistor fixed, then wire it all, then 3D print the boxes (which open and close, so I can remove a kceptor if needed without any trouble). Then I'd do the velcro, because again, I'm just feeding it around a box, so it's easy to undo, and then I'd deal with Blender.

How would I get the default_biped_configuration working without having it on my actual body or without calibrating it all first?

daylanKifky

konokaiden How would I get the default_biped_configuration working without having it on my actual body or without calibrating it all first?

You can just lay them all on a table, connect them together with the Hub and raspberry and run the notochord with the default_biped configuration.
I've seen many users having problems at this step: perhaps connectivity issues, soldering problems, software misconfiguration, etc.
If you spot these problems at this step they are easier to solve, and saves you the frustration of doing a lot of work to find out that a tiny detail forces you to undo some of it.*
Once you have it working you can also go ahead and send the data to blender. You will get a mess of entangled bones, probably slowly drifting because of the lack of calibration, but you should be able to see a particular bone moving if you move one of the physical sensors. If I were you I would check each sensor is responding using that method at this stage.
At this point you will be pretty certain that the core of your system is indeed working, and it would be a good time to wrap up the details like fixings or so..

(*)
This is a general rule I (and many others) apply to complex developments, it's know as the "Fail fast rule": It's better to identify all the possible errors of your system at the beginning, before start doing the finishes

PS: If you do the table test, please post some photos or videos of it, we can use them to explain the process to others easily 😉

konokaiden

I have the wires crimped and such now. I'll post pics of that later. I hope to do the table test later today, and I'll probably post a video of that, since I'll be moving between two rooms.