Can't recognize my Mini Hub

ChangyeobOk

valor My bad. The power was on.
SDA1: 10.8 K ohm
SCL1: 2.9K
2: 10K
2: 2.6K
3: 9K
3: 9.7K
4: 1.9K
4: 5.4K
5: 1.8K
5: 9.4K
6: 9.3K
6: 9.3K

As I clean the board again and again, the value gets closed to 10k. Strange huh?

Thanks for your advice but it's 4pm here. I will try to check the solder joints again. 😉

valor

ChangyeobOk
Okay, we might be on to something. Those readings are definitely off. Each of those should read as 9-10K.
Your U5 might be defective.

ChangyeobOk

ChangyeobOk After I touched the joints with a fine tip soldering iron, every joint is around 10k. Bravo!
SDA1: 10.8
SCL1: 10
10
10
10
9.7
9.9
9.9
9.9
9.8
9.5
9.6
The SDA1 is a little high and SDA6, SCL6 are a little lower but other points are almost 10K.
I think I overestimated my soldering skill. :p

ChangyeobOk

ChangyeobOk This time hub doesn't show up on i2cdetect -y 1 command. Which pin is related to hub detection?

valor

ChangyeobOk
SBC_SDA and SBC_SCL

ChangyeobOk

valor I wish I had a microscope. I am relying on the magnifying glass on my helping hands. 😅

valor

ChangyeobOk well the best tool is the tool you have 😉

ChangyeobOk

daylanKifky
While I am trying to fix the soldering issue on my hub board, I get different result for i2cdetect -y 1.
My first mini-hub appears on 0x71,
My second mini-hub appears on 0x73 at first but after I tried to fix soldering issues(retoucing the joints between chip and the board with soldering iron), it appears on 0x70

Do you have any idea what's happening? Why does it need to be always 0x73?

ChangyeobOk

ChangyeobOk I have assembled my 3rd mini-hub and it's working well. However, I would like to fix the 1st and 2nd boards for later projects.

ChangyeobOk

ChangyeobOk I get different result for i2cdetect -y 1.
My first mini-hub appears on 0x71,
My second mini-hub appears on 0x73 at first but after I tried to fix soldering issues(retoucing the joints between chip and the board with soldering iron), it appears on 0x70

Do you have any idea what's happening? Why does it need to be always 0x73?

@daylanKifky Do you have any idea by chance?

valor

ChangyeobOk sounds great! On the 2nd board: try replacing the U5 first.

daylanKifky

Hi!
The address of the Hub is set at U5's pins A0 and A1 by the resistors R2 and R3. With the configuration as in the scheme below the address should be0x73`

Check these resistors on your first Hub.

With that said, the notochord can be configured to read another address for the Hub. You know that it reads an XML file upon startup? it is normally called Chordata.xml but you can also pass another file like the default_biped.xml. Take a look at the <Mux> tag on those files: it contains the address 0x73. If you are getting a (consistent) different address you can use it this way

ChangyeobOk

daylanKifky Check these resistors on your first Hub.

They are all 10k but when I measured, some of them are lower than expected(8.6k). Then I retouched the pin un U5 that is connected to the resistor, it went back to normal(9.6k. still lower than 10k) and it showed up on 0x73.

daylanKifky for the XORH and XORL pins on the U2 of the KCeptor

I only see the XORL pin here.
https://easyeda.com/editor#id=1e9cd3d4887145d09b6f5b185f2ca3d4
@valor Am I missing something?
I have soldered 4 K-ceptors so far but none of them are showing up on ./find_KCs.sh

I feel like this is all the soldering issue. I wanted to get Chordata on Kickstarter but my project is due in November.
Also wanted to request assembly from JLC PCB but Mini version is too small to ask the service. Should I get the original version that is assembled from JLC PCB? I see they don't have some components like IMU.
If someone has done the assembly request, please share your experience...

valor

There must be a resistor mismatch if your hubs are getting different addresses, since my built is specifically made around 10K resistors, to keep the BOM short. As @daylanKifky suggested, theck those resistors. Since you fixed your earlier problem with the SDA and SCL pull up resistors being all over the place by touching up, i'd suggest that you do the same. You might also check if your flux is slightly conductive (it'd surprise me, but checking takes no time)

daylanKifky

valor You might also check if your flux is slightly conductive

Most flux have some conductivity indeed. In my experience it's particularity problematic for the XORH and XORL pins on the U2 of the KCeptor, giving erroneous translation addresses

valor

ChangyeobOk
At this point I suggest that you clean your flux off the PCB. Your flux does not sound like a no-clean flux.
Regarding the XORL, that's correct. Inly XORL is configured in the K-ceptor (and Mini K-ceptor) design, and the XORH is hardwired to the ground

The number on my multimeter fluctuating for RLT and RLB reads as 124k.

Do you mean both resistors read the same value?!?
What resistance does your multimeter measure across a single, non soldered 182K resistor on a table?

ChangyeobOk

connected one of my KC (supposed to be [2]. 976k and 182k attached) and I have this.

I measured the RLT, RLB resistors. The number on my multimeter fluctuating for RLT and RLB reads as 124k. After retouching the pins on U2 the result is the same... Don't understand what's causing a resistor's value fluctuating.

daylanKifky

In order to better see the values your KCs are getting you can use:

i2cset -y 1 0x73 0xFF && i2cdetect -y 1

This command will first open all the gates of the Hub, and then perform the detect part, so be sure to only plug 1 KCeptor at the time

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