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In this video, I engage in a deeper exploration of USB testing, encountering a range of trials and tribulations along the way. First up, I attempt to test a couple of USB cables and discuss their data lines' peculiar situatedness. Then, I delve into the assembly of the PCB boards, sourced from PCBWay, which surely turned into a learning voyage than an easy sail. The first version faced challenges of misordered large-frame stencil, unseen connection problems, and even DRC errors in the submission process. Not dwell on that, I redesign and bring to table Version 2, complete with USB connectors with broken-out pins and designed for visual inspection ease. Although this version demonstrated success, soldering difficulties and bad connections persisted. Considering all the hurdles, I decide to let PCBWay handle the assembly for the next version. For future strategies, adding test points and eliminating the lithium-ion charging circuit seemed more practically viable. Peeping into version 3, testing points for all USB cable pins have been added and even an option to break out actual USB connections, all towards ensuring an improved error checking and usefulness of the assembly.

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Transcript

[0:00] I’ve made myself a little USB tester
[0:03] So let’s try out this cable
[0:05] Plug in that end
[0:07] And then we plug in this end
[0:09] So you can see this cable is pretty good
[0:13] But it’s not going to do high speed USB
[0:15] Because it’s only got the two data lines
[0:18] It is interesting that there’s only data lines on one side of the cable
[0:22] So if I flip this over
[0:24] You can see our two data lines have swapped over
[0:29] So that’s pretty interesting
[0:31] So here’s another cable
[0:34] Let’s plug this in
[0:36] So this cable is pretty impressive
[0:39] Pretty much every single light is lighting up
[0:42] So this will do full high speed USB 4
[0:46] 40 gigabits per second
[0:48] So pretty impressive
[0:50] It’s interesting though that the two data lines
[0:53] are once again only on one side of the cable
[0:56] So if we just flip this over
[0:58] You can see our data lines have moved over
[1:01] So that’s pretty interesting
[1:03] Now all of these boards came from PCBWay
[1:05] As always did a fantastic job
[1:07] Check out our link to the PCBWay guys in the description
[1:11] But let’s talk about the actual assembly of these boards
[1:14] Because it was quite an interesting experience
[1:17] So this has been quite a traumatic experience
[1:23] Here’s version one of the board
[1:26] We have our two USB sockets
[1:28] which connect using these little USB connectors
[1:31] with all the pins exposed
[1:33] And we have our nice little battery connector
[1:36] for a coin cell battery
[1:38] And I’ve also got these rechargeable lithium coin cells
[1:42] which you can charge up using this nice little charger
[1:45] So that’s pretty cool
[1:47] So the first mistake I made was ordering the stencil
[1:53] This is not particularly practical
[1:56] So what happened is
[1:58] I ticked the wrong box when ordering the stencil
[2:01] and completely missed the fact
[2:03] that I ordered the very large framed version
[2:06] Possibly good for a wall decoration
[2:09] Not particularly practical for dispensing solder paste
[2:13] But fortunately that gave me a chance
[2:19] to try out the Voltaire for solder dispensing
[2:22] [machine working]
[2:44] And here’s what we’ve ended up with
[2:46] Note the bodge wires
[2:48] So another mistake I made when submitting this
[2:51] Despite my usual very careful checks
[2:54] and sleeping on the PCB overnight
[2:57] I managed to submit something with DRC errors
[3:00] So quite a few of the connections were just not connected
[3:03] So that’s a bit unfortunate
[3:05] Let’s try this out
[3:06] We’ll plug some cables in and see what happens
[3:09] So I have my little test cable here
[3:12] Can connect that one
[3:18] And we’ll connect this one
[3:20] So quite a few things light up
[3:23] It actually works
[3:25] but I know for a fact
[3:27] that this cable doesn’t have
[3:29] RX-, TX-, and it doesn’t have SBU2
[3:35] So what’s happened here
[3:38] is that these pins are actually really hard
[3:44] to visually inspect and connect
[3:47] Unfortunately a lot of the connections
[3:50] are hidden underneath the USB socket
[3:53] So you can’t really tell what’s happened
[3:56] and whether it’s connected or not
[3:58] So that was version 1
[4:01] Not very good
[4:03] So we come over to version 2
[4:07] This has been completely redesigned
[4:10] I’m now using these USB connectors
[4:13] which have the pins broken out with through-hole
[4:17] and the other pins broken out
[4:19] so you can actually see them
[4:21] So this is actually quite easy
[4:23] to visually inspect
[4:25] This time I ordered the proper stencil
[4:28] making life considerably easier
[4:31] The other change I made
[4:33] is I added on the option
[4:35] of having a rechargeable battery
[4:38] so you can get a lithium cell to this
[4:41] directly using this connector
[4:43] Now in hindsight
[4:45] maybe that’s a bit over the top
[4:47] as these coin cells will pretty much
[4:49] last forever given the use case
[4:51] But let’s get this assembled
[4:53] and we’ll see how it works
[4:55] [Music]
[5:18] So this is the most successful one
[5:21] I’ve managed to make
[5:22] but it’s still very difficult
[5:24] to get these USB connectors soldered on
[5:28] without causing solder bridges
[5:30] or making bad connections
[5:32] But this one works reasonably well
[5:34] You can see there’s a D- missing
[5:36] which should be there
[5:38] I don’t know if we flip this over
[5:40] There we go
[5:42] That’s a slightly better connection
[5:44] but you can see I’ve got a bad connection
[5:46] somewhere on a ground
[5:47] So I think for version 2
[5:49] I might just get PCBWay
[5:51] to actually do the assembly
[5:52] because life is way too short
[5:54] to be doing a bit of pick and place
[5:56] at home manually
[5:57] when you’re doing so many resistors
[5:59] and so many diodes
[6:00] and trying to place these USB connectors
[6:03] I just can’t get them to work properly
[6:05] so I’ll leave it to the professionals
[6:07] But what I might do
[6:09] is add a bunch of test points
[6:10] so it’ll be much easier to detect
[6:12] when there is a short
[6:13] so I can do some quality assessment
[6:15] and then reject the ones
[6:17] where they don’t work
[6:18] So it’s pretty nice
[6:19] looks very pretty
[6:20] lots of coloured lights
[6:21] If I do get something actually consistent
[6:23] and working well
[6:24] then I might stick this up somewhere
[6:26] for people to buy
[6:27] because I think it would be
[6:28] quite a useful tool
[6:29] What I will do is probably
[6:31] get rid of the additional
[6:34] lithium ion charging circuit
[6:36] I think a coin cell
[6:38] is more than sufficient
[6:40] for this use case
[6:41] especially these nice
[6:42] rechargeable coin cells
[6:44] So this is my initial thought
[6:49] What I’ve done is added test points
[6:51] for every single pin
[6:53] on the USB cable
[6:55] so we can do this best
[6:57] with the 3D viewer
[6:59] So here we go
[7:00] I’ve got all these nice test points
[7:02] so in theory
[7:04] it should be quite easy
[7:06] to test all of these
[7:08] and check for any shorts
[7:10] But then I had another idea
[7:12] and I thought
[7:13] wouldn’t it be much better
[7:14] if we could break out
[7:16] the actual USB connections
[7:18] So here’s version
[7:20] I don’t know what version this is
[7:21] Here is another version
[7:23] So what I’ve done here
[7:24] is I’ve actually put
[7:25] some header pins
[7:26] so we can actually
[7:27] connect to the USB connections
[7:29] So let’s have a quick look
[7:30] at how this looks
[7:31] in the 3D view
[7:33] So I’ve got one header
[7:35] for connecting up
[7:36] the two battery terminals
[7:38] and then this header
[7:39] in the middle
[7:40] will break out
[7:41] all of these USB connections
[7:43] So I think that’s actually
[7:44] pretty useful
[7:45] So I’ll probably go
[7:46] with this design
[7:47] It would be very easy
[7:48] to make a board
[7:49] that slots into this
[7:51] that could actually check
[7:52] all of the connections
[7:53] and make sure
[7:54] there’s no shorts
[7:55] So I think that would be
[7:56] pretty cool
[7:57] So I’ll send this off
[7:59] This time I’ll do
[8:00] a bit more sleeping on it
[8:02] and I will double check
[8:03] every single connection
[8:05] to make sure
[8:06] I’ve not missed something
[8:07] But I think this version 3
[8:09] should be good


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Chris Greening

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atomic14

A collection of slightly mad projects, instructive/educational videos, and generally interesting stuff. Building projects around the Arduino and ESP32 platforms - we'll be exploring AI, Computer Vision, Audio, 3D Printing - it may get a bit eclectic...

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