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Built my first Cameo Aphid. Could use some help

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stepleton:
Hmm, it should work pretty well when attached to the parallel port card. How long a cable are you using? A shorter cable (ideally under a foot) will be best.

If you're already using a short cable, and if the cable has good continuity on all of the pins, then there could be a problem with the assembly of Cameo/Aphid itself. Things to check:

- Are the resistors placed exactly as shown here?
- Are there any shorts between the legs of the ICs?
- Are the ICs oriented the correct way?
- General condition of solder joints everywhere.

A different question: when you try to boot from the STARTUP FROM... menu, do the User LEDs on the PocketBeagle blink off momentarily? Does the one dark LED turn back on?

Verault:
Take a look, let me know if these are clear enough. https://photos.app.goo.gl/3DAkbGuuo7Wic9L78

But just for clarification, should I be able to see a working FAT partition on the micro SD card after the image is copied over and Its connected to my PC?

stepleton:
Well, your cable is certainly short enough. Looking at it closely, it appears to be wired correctly as well (for example, neither of the connectors appear to be the wrong way round).

Can you confirm continuity and no shorted pins? It's a drag, but that's debugging... Beeping out each wire in the ribbon cable might be worthwhile, as might confirming that no two DB25 pins that correspond to adjacent wires are connected (so pairs like pin1-pin14, pin14-pin2, pin2-pin15, pin15-pin3, and so on). It would be nice to competely eliminate the cable as a factor. I notice in this photo that a grey and a purple wire on the header connector end may have some ragged ends --- could that be a short?

The soldering on the Cameo/Aphid board looks good at a quick inspection, and all of the components seem to be in the correct places. In fact, your technique for soldering the ICs looks nicer than my own. That said, problems with SMT soldering for ICs can be difficult to spot. It seems unlikely that any of the legs are shorted, but one other possibility is that one or more of the legs do not have a good bond to the PCB pad. I've encountered this problem on other projects, and it can be almost impossible to see without a microscope (which I don't have!).

Therefore, checking continuity between the legs of the ICs and the places they connect to (for which you'll have to refer to the schematic) might be worthwhile. You might also be able to accomplish this check without the schematic by delicately placing one probe lead on the IC leg and the other probe lead on the bit of pad that sticks out from underneath it. Of course, pressing down too hard on the leg could complete the broken connection and temporarily "fix" the fault.

If all of those things are fine, the next area to investigate is probably the Beagle-to-Aphid header connectors. Attaching headers to the PocketBeagle can be tricky to do, especially right around the SOC package itself (so pins 6,8,10,...,22 of P1). In the worst case, if soldering those pins involved high heat and/or long dwell times, it might have been possible to melt some of the ball solder joints underneath the SOC. I'm not too worried about this, because your system still boots, but I also note that P1 pin 14 in this photo seems like it might have a wee "blob" that could reach under the SOC? It's very hard to tell, especially since that part of the photo is still dark.

That's most of what I can think to check for right now, other than very basic things like making sure that your PocketBeagle and the Cameo board were plugged into each other the right way round. What test equipment do you have available for debugging the problem --- do you have an oscilloscope?

As far as seeing a FAT partition goes --- I don't know for Windows 7, unfortunately, but I have seen Windows 10 not show the CAMEO_APHID partition automatically. I can describe my Windows 10 procedure for getting the partition to show up on insertion; maybe you will be able to find a similar Windows 7 method.

- First, put the SD card into the computer. Dismiss any messages about needing to format.
- Open the Disk Management control panel (use the Start search box for "Create and format hard disk partitions").
- In the bottom half of the window, you'll be able to see a row corresponding to your SD card. It should have two partitions and probably some empty space. (You may need to scroll.)
- Select the second partition, right click, select "Change Drive Letter and Paths...".
- Click the Add... button. Choose a drive letter for the partition next to the "Assign the following drive letter" option.
- Select "OK" and then "OK" again.

stepleton:
Also, when you have a chance, can you remark on this question from earlier: "when you try to boot from the STARTUP FROM... menu, do the User LEDs on the PocketBeagle blink off momentarily? Does the one dark LED turn back on?"

If yes, then we know at enough of the connections are working to get Cameo/Aphid through part of the ProFile handshake. This would be a useful clue.

Verault:
Thank you for taking the time to help me on this I really appreciate it. I will take some time and check the cable for continuity and check for shorts on the board as well. I will post back when I have gone over everything.

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