LaPOD: Low cost Logic Analyzer probe for MSO5k, DHO900 and more!

[Electro Fan]

Have you made one of these yet? I'd be very interested to see one.

Me too :p

LOL

oliv3r you do great work 

[Songhua]

Now it's June 2024, have you made one?

Expect to see a real-working one.

[maxora]

Hi Guys,

So I made the thing. (POD_LMH7324 and Mini_HDMI_Breakout)
I ordered the PCBs and parts, and soldered by hand.
Checked for any dry joints or bridges. Didn't find any issues.


However, when I connected the probe to the scope, it did not work at all. I also noticed that the LMH7324 is getting hot.

So I started checking the connections and noticed that some pins are shorting out only when the HDMI cable is plugged to both PCBs.

To narrow-down the issue, I connected a HDMI header and a mini HDMI header (not soldered to the PCBs) and started checking the connections between two ends.
And that's when I noticed that the pins of the mini HDMI connector (Type C) are not in the same order as the HDMI connector (Type A).
But in the mini_hdmi_breakout PCB, the pins are in the same order as the Type-A header.
(The cable I used is a high speed HDMI cable with Ethernet)
I think someone else also should test the pin connections and confirm this. (just to make sure...)

And this is the pin order I got with my test. (Sorry about the messy image. I am too lazy to make it pretty...  )

There was no connection on pin 17 of mini HDMI connector. Not sure why though...

However, I think the HDMI breakout board should work fine. So I am going to order the PCBs for that.

[Songhua]

I'm very happy to see someone finally made an actual one.

I read that you had problems with the pins.

Did you fix it? Now. Please keep updating in this post. Appreciate your comments!

[qmichl]

I built also one with pod_sn65lvds low cost pods. And I found that the TLV74325PDBVR is a 2.5V LDO, while the SN65LVDS391PWR requires 3.0V-3.6V supply voltage. So that is the wrong voltage regulator. And R13 need to go to +3.3V instead of GND, otherwise half of the channels on the pod are disabled. The breakout_hdmi (not mini) seems to work so far, still testing.

[qmichl]

The pod_sn65lvds pods do not have GND of the SN65LVDS391PWR connected, that need to be fixed by a small wire.

The 100Ohm termination is not correct, that should be on the HDMI breakout instead on the pod_sn65lvds pod.

[jsobell]

Yes, I can see in the KiCAD schematic that the connectors pin numbers are incorrect 
I suspect @Oliv3r simply replaced the full size with a mini version without realising it had a different pinout.
This is one of the main reasons I avoid KiCAD and use EASYEDA. At least with that product it uses the models directly from LCSC, so you're guaranteed to have the correct pinouts.

Sorry, I don't see an easy workaround, other than either reordering using the standard HDMI breakout, or correct the mini HDMI breakout board replacing all HDMI_A with  HDMI_C_1.3 components. It's the same schematic footprint, but with the pins corrected, but then you'll need to re-route the entire PCB to correct it 

Here are the two different connectors. Click the 'EasyEDA Model' link to see the pinouts.
https://www.lcsc.com/product-detail/HDMI-Connectors_SHOU-HAN-HDMI-19PIN-043_C2858275.html
https://www.lcsc.com/product-detail/HDMI%20Connectors_XKB-Connection-A71-05H4-111N1_C2682170.html