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View Full Version : U2 programmer problem - Saleae Logic Probe measurements, SOLVED



Demon
- 15th May 2011, 03:24
This started while completing a school project with my daughter:

- U2 USB programmer on Core2Quad-2600 PC.
- problems started after a few days of normal operation.
- 16F877 seems to program properly according to MeLabs pgmer messages.
- mcu fails to run properly on circuit.

- moved to old MeLabs Serial programmer on AMD-1800 PC.
- no problems at all using same mcu and circuit.

- tried U2 USB programmer on AMD-1800 PC.
- no problems at all using same mcu and circuit.

I have no clue what's going on. I've used many USB devices on the C2Q, the programmer had worked properly for several days. I tried front and rear USB jacks, no difference.

So I decided to connect the Saleae Probe using identical settings and see what's going on. MCLR has apparent differences right away at end of programming cycle. PGC and PCD also have differences but I didn't bother trying to get pics of those.

I would have liked to get faster sample rates, but there's a limit to the buffer size; the faster you go, the less time you can collect.

5504

Identical PIC environment on both PCs:
Windows XP Home SP3
PIC Basic Pro v2.60c
Microcode Studio Plus v3.0.0.5
MeLabs U2 Programmer v4.32
Saleae Logic Probe v1.1.8

HenrikOlsson
- 15th May 2011, 07:18
Hi Robert,
I'm afraid I currently have no idea what your actual problem is and I don't see any apparent difference between the two screenshots, what is the problem that you see on the trace? Anyway, I thought I'd write you a line about LOGIC.

Yes, there's a limited amount of samples but surely you can have more than 1M AND higher samplig frequency. On a slow(ish) computer you might not be able to reach 24MHz but you should be able to go WAY up from where you are now. Just select, say 10M samples at 500kHz instead. Or does that not work for you for some reason?

You can give each channel a name in the software, just click on the text Channel 1, Channel 2 etc and punch in your name. That way you don't have to photoshop that in later.

I don't see you have any trigger set up, did you capture it "on the fly"?

/Henrik.

Demon
- 15th May 2011, 15:20
Yup, no trigger. I just watched the programmer messages and started the sampling as soon as the Verification step finished.

I started at 1M but the sampling ended quickly. The slower the speed, the more time the sampling lasted. The programming step lasts over 10 seconds so I had to go all the way down to get it all.

Thanks for the labelling idea, didn't read the manual yet. I just wanted to try something with my new toy and thought that it might help figure what is wrong with the U2 on only 1 PC.

Demon
- 15th May 2011, 15:43
Hi Robert,
I'm afraid I currently have no idea what your actual problem is and I don't see any apparent difference between the two screenshots, what is the problem that you see on the trace? ...

Here's a zoom of the end of the programming cycle (sorry, I inverted the PCs from the pervious pic).
5506

EDIT: There's a bit more activity on the bottom chart from 14.7s, and that's the PC that programs properly.

HenrikOlsson
- 15th May 2011, 15:53
Hi,
OK, now I see the difference, I still have no idea what the problem might be though.

To the left of the sampling frequency drop down box you have another dropdown where you select how many samples to take at your currently selected sampling frequency. You can take as much at 10G samples which, at your current rate of 50kHz would last 55h. Even at the highest sampling frequency, 24Mhz (if you computer can keep up) 10G samples will last almost 7 minutes(!).

/Henrik.

Demon
- 15th May 2011, 16:18
There's also activity on PGC on the AMD PC after 13.6s. I went back for a better pic in case it was an issue with the zoom not yet picking up a short signal:

5507

I'm definitely missing pulses on the C2Q PC and have no clue why that would be.

Either something is wrong with the USB ports, which is unlikely 'cause every other device works properly; gaming wheel/yoke/thrust quadrant/joystick, mouse, keyboard, digital camera, logic probe, etc.

Or something is wrong with the U2 programmer at the driver level, 'cause the hardware works properly on the other PC.

Demon
- 15th May 2011, 16:21
...Even at the highest sampling frequency, 24Mhz (if you computer can keep up) 10G samples will last almost 7 minutes(!)...


I'll test this after breakfast (wife bellows).

Demon
- 15th May 2011, 16:26
...I don't see you have any trigger set up...

What would you suggest?

I figure using MCLR is the key, but under what conditions?

I checked the manual but didn't see too much detail on trigger. I've never used a "trigger" before, it does exactly that right? It starts the procedure and then that condition is ignored?

So I'd look for MCLR going up?

I assume getting rid of that Blank Check Before and Verify After steps could help too, it's not really necessary.

mister_e
- 15th May 2011, 21:38
Disconnect any extra hardware attached to your computer (camera, printer & plah plah plah)

Clean the USB driver with UsbDeview, reconnect your U2 programmer, wash & rinse again.

mister_e
- 15th May 2011, 21:39
BTW, is the Saelig probe able to handle the 13V (or so) on the MCLR pin?!?

Get rid of it while programming.

Demon
- 15th May 2011, 21:59
I upped the rate to 100M@200KHz.

(the bottom PC is the one that programs properly)

This is the start of the programming step:

5508

At first glance things look practically identical. The only thing I haven't figured yet in Logic is how to get the same zoom ratio to make it easier to visually compare 2 windows.


This is a zoom on that very first PGC signal from the red box:

5509


The PGC signals are somewhat delayed relative to PGD.


And this is the second PGC signal:

5510

An even bigger difference in signals.


I guess I'm stuck to using the old Pentium 4 until I figure this out.

(I have to say I love my Saleae logic probe)

Demon
- 15th May 2011, 22:48
Disconnect any extra hardware attached to your computer (camera, printer & plah plah plah)

Clean the USB driver with UsbDeview, reconnect your U2 programmer, wash & rinse again.


I only have mouse and keyboard attached.

Cleaned with Usbdeview, uninstalled programmer, rebooted, reinstalled v4.32 from CD and everything works ok!

Merci le Bleuet!
:)

mister_e
- 15th May 2011, 23:06
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[Insert Big Grin here]