Kisssys board issue w/ uSD. M4 long boot time, high MCU

[aBUGSworstnightmare]

Hi Mullet,

please do me a favour and make the following test:

- Mount the 'bad' M4 to the aBUGSworstnightmare Expansion board
- insert the uSD which gives you 100% MCU load into the board
- connect the M4 to your PC (USB connection only)

--> since you have removed R26 the board should boot flawlessly
--> what is the MCU load?
--> does the board log?

Why can't you pair the board with your TX?

You can't do any harm to the aBUGSworstnightmare M4 Expansion board even when using the 'bad' M4 (since I still doubt there is a Problem with the M4 itself).

You have soldered the KISSSYS Expander by your own --> are you sure it's working 100%? I spend a fair amount of time to check each and every board I've build, measuring every signal line/voltage level before testing with M4r5 and M4r6 flight Controllers.

Just one thing to notice: When you make testings be sure to compare an apple for an apple! Never try to hunt-down a (what you think atm) Hardware failure by using differnet Software on different systems

[Mullet]

Here are some findings. They mirror what I've been seeing all along.

For testing... I've made sure both M4s are on same firmware. I ended up using aqv7.0.r442.b1848-hwv8.6-quatos.bin for both. Both boards are binded to DX7s. Only difference is "bad" M4 has R26 removed and "good" M4 doesn't - it never had boot problems.

1) Tested with BLDC board. Power is provided via USB.

Results:
"Bad" M4 - creates log, log grows in size, uSD doesn't mount on desktop. MCU ~55% in QGC.
"Good" M4 - creates multiple logs, logs don't appear to grow, uSD mounts on desktop. MCU ~55% in QGC.

2) Tested "Bad" M4 with Kisssys board via USB power.

Results:
No logs created. M4 has 100% MCU in QGC.

I'm thinking Kisssys board is cause of problems. I might have solder bridge somewhere inside uSD slot. Pictures are provided for analysis. Not sure why uSD won't mount with "Bad" M4 using BLDC.

Other ways to test:
-I can remove R26 from "Good" M4 to see if that makes a difference.
-Add battery leads to "Good M4 and only test with battery power with MLDC board connected.

I'm thinking the only options I have are:
Try and use hot air rework station to remove uSD slot and re-solder.
Buy another Kisssys board. Try again.
Figure out if "Bad" M4 is truly bad. The only indication of this is that the good and bad M4s act differently even with MLDC e.g. uSD mouting on desktop or not.

I'm weary of plugging the Kisssys into "Good" M4. I don't want to possibly ruin two M4s. I did test it and got 3v3 with jumper wire, so I figured I was ready to go. Does the uSD need 5v?

[Mullet]

Ooops forgot to add the pics and latest logs...

Good M4 with BLDC.zip

(168.87 KiB) Downloaded 534 times

Bad M4 with BLDC.zip

(4.12 MiB) Downloaded 564 times

[Kisssys]

The Kiss board only has passive components so it's either a bad socket or soldering, most likely it's a bad solder joint or bridge somewhere. It's not easy to hand solder so don't feel bad.

Looking at the photo I can see at least one pin on J1 that has solder on the pin and not on the pad.

Be cautious when you use the onboard 3v3 volts to power a BT module, that is the same buss as the sensors and it
may cause an issue.

Cheers
Steve

[Mullet]

Yeah hand soldering this board isn't easy with the headers so close to the uSD slot. I've don't plenty of 0603 devices with a magnifying lamp. I haven't even tried powering the BT module yet. Waiting on wiring from China. I have the HC-06, which looks to work with 3v3. Should I just get a pololu?

I will try and re-flow the solder on that joint. Maybe that's the issue.

With the Kisssys board, does the uSD mount on a computer desktop (Mac) or with a drive letter on Windows?

Also, what does J8 do?

[Kisssys]

It is suppose to mount as a drive or give you a drive letter. You can access the uSD card and read, write or delete as any other mass storage device.

You connect to QGC by selecting COMx - AQ MSC-CDC COM Port at 600 baud. It's not really at 600 baud, that's just a signal to the M4 you would like to connect to the Uart with Mavlink. If you put in 1200 baud you could talk direct to the GPS onboard.

[Mullet]

OK... so I've had a little progress.

Re-flowed that pin on J1. Now I don't get 100% MCU. Also, have been able to get intermittent logs with "Bad" M4 and KISSSYS with both USB and battery power. If I jiggle the uSD card in the right way when its in its slot I can get it to log. I can't get the card to mount on my desktop when plugged in via USB. It seems there is something wrong with this M4 board and mounting the uSD card. This is happening with both the BLDC and now KISSSYS.

I might at this point be willing to try the KISSSYS with the known "Good" M4.

[Kisssys]

Some uSD cards are a little thin, a little tape on the side can fix that.

I just tried R441 and mine wouldn't mount either, I tried 427 and it worked fine. Let me check and see if others are having a problem.

What version software are you using?

[Mullet]

I'm using R442 on both.

I'm not having very good luck with this. I'm going to keep trying though. I was able to get my "good" M4 to mount uSD every time or pretty much every time. I thought since things were starting to work out better that I would try plugging the KISSSYS board into the "good" M4. It actually mounted the uSD! OK good start. But then after that now even with the BLDC I've gotten the uSD to mount only a few times after trying 20 or 30 times. My KISSSYS is cursed.

On top of that my other "bad" M4 is even worse now. When I plug in the battery I can turn it on. But can't turn it off via the on/off switch. I have to pull the battery now to shut it off.

I refuse to throw in the towel.

[Kisssys]

We may have a mounting issue so pull the uSD card and read it directly until we narrow down what that is all about. I normally just pull the card, not sure what most guys are doing. If the green is flashing quickly then it's logging, when it's logging you won't be able to mount it. It should stop logging when the USB is plugged it.

You may have a bad board if you can't turn it on and off. It would probably still work fine as a controller until you get it fixed. I have one board I shorted out and it stays on all the time. I just use it that way until I feel ambitious and change the charge controller chip.

It might be easier to follow if we deal with one board at a time.